Form 10-Q - Quarterly report [Sections 13 or 15(d)]

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

(Mark One)

☒	QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended June 30, 2024

☐	TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

Commission file number: 000-51026

Monolithic Power Systems, Inc.

(Exact name of registrant

as specified in its charter)

Delaware

77-0466789

(State or other jurisdiction of

incorporation or organization)

(I.R.S. Employer

Identification Number)

5808 Lake Washington Blvd. NE, Kirkland, Washington 98033

(Address of principal executive offices)(Zip Code)

(425) 296-9956

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading Symbol

Name of each exchange on which

registered

Common Stock, par value $0.001

per share

MPWR

The NASDAQ Global Select Market

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Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer ☒	Accelerated filer ☐	Non-accelerated filer ☐
Smaller reporting company ☐	Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒

There were 48,752,000 shares of the registrant’s common stock issued and outstanding as of July 26, 2024.

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MONOLITHIC POWER SYSTEMS, INC.

Form 10-Q

For the Quarter Ended June 30, 2024

TABLE OF CONTENTS

		PAGE
PART I. FINANCIAL INFORMATION		4
Item 1.	Financial Statements (unaudited)	4
	Condensed Consolidated Balance Sheets	4
	Condensed Consolidated Statements of Operations	5
	Condensed Consolidated Statements of Comprehensive Income	6
	Condensed Consolidated Statements of Stockholders’ Equity	7
	Condensed Consolidated Statements of Cash Flows	8
	Notes to Condensed Consolidated Financial Statements	9
Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	28
Item 3.	Quantitative and Qualitative Disclosures About Market Risk	35
Item 4.	Controls and Procedures	35

PART II. OTHER INFORMATION		36
Item 1.	Legal Proceedings	36
Item 1A.	Risk Factors	36
Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds	37
Item 3.	Defaults Upon Senior Securities	37
Item 4.	Mine Safety Disclosures	37
Item 5.	Other Information	37
Item 6.	Exhibits	38

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PART I. FINANCIAL INFORMATION

Item 1. Financial Statements

MONOLITHIC POWER SYSTEMS, INC.

CONDENSED CONSOLIDATED BALANCE SHEETS

(In thousands, except par value)

(Unaudited)

	*June 30,*			*December 31,*
	*2024*			*2023*
ASSETS
Current assets:
Cash and cash equivalents	$	550,475		$	527,843
Short-term investments		756,770			580,633
Accounts receivable, net		157,890			179,858
Inventories		426,751			383,702
Other current assets		105,547			147,463
Total current assets		1,997,433			1,819,499
Property and equipment, net		400,534			368,952
Acquisition-related intangible assets, net		10,512			-
Goodwill		26,080			6,571
Deferred tax assets, net		29,707			28,054
Other long-term assets		183,866			211,277
Total assets	$	2,648,132		$	2,434,353

LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Accounts payable	$	99,894		$	62,958
Accrued compensation and related benefits		63,917			56,286
Other accrued liabilities		131,348			115,791
Total current liabilities		295,159			235,035
Income tax liabilities		60,440			60,724
Other long-term liabilities		96,675			88,655
Total liabilities		452,274			384,414
Commitments and contingencies
Stockholders’ equity:
Common stock and additional paid-in capital: $0.001 par value; shares authorized: 150,000; shares issued and outstanding: 48,698 and 48,028, respectively		1,224,144			1,129,937
Retained earnings		1,016,208			947,064
Accumulated other comprehensive loss		(44,494	)		(27,062	)
Total stockholders’ equity		2,195,858			2,049,939
Total liabilities and stockholders’ equity	$	2,648,132		$	2,434,353

See accompanying notes to unaudited condensed consolidated financial statements.

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MONOLITHIC POWER SYSTEMS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except per-share amounts)

(Unaudited)

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Revenue	$	507,431	$	441,128	$	965,316	$	892,193
Cost of revenue		226,853		193,453		432,297		385,738
Gross profit		280,578		247,675		533,019		506,455
Operating expenses:
Research and development		77,945		63,688		153,935		127,397
Selling, general and administrative		86,097		71,662		167,061		142,457
Total operating expenses		164,042		135,350		320,996		269,854
Operating income		116,536		112,325		212,023		236,601
Other income, net		7,512		6,543		17,052		11,840
Income before income taxes		124,048		118,868		229,075		248,441
Income tax expense		23,682		19,364		36,168		39,135
Net income	$	100,366	$	99,504	$	192,907	$	209,306

Net income per share:
Basic	$	2.06	$	2.10	$	3.96	$	4.42
Diluted	$	2.05	$	2.04	$	3.94	$	4.30
Weighted-average shares outstanding:
Basic		48,687		47,489		48,660		47,361
Diluted		48,945		48,756		48,935		48,705

See accompanying notes to unaudited condensed consolidated financial statements.

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MONOLITHIC POWER SYSTEMS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME

(In thousands)

(Unaudited)

	*Three Months Ended June 30,*						*Six Months Ended June 30,*
	*2024*			*2023*			*2024*			*2023*
Net income	$	100,366		$	99,504		$	192,907		$	209,306
Other comprehensive loss, net of tax:
Foreign currency translation adjustments		(4,313	)		(26,180	)		(18,135	)		(23,261	)
Change in unrealized gains and losses on available-for-sale securities, net of tax of $50, $158, $(198) and $469, respectively		368			728			703			2,941
Other comprehensive loss, net of tax:		(3,945	)		(25,452	)		(17,432	)		(20,320	)
Comprehensive income	$	96,421		$	74,052		$	175,475		$	188,986

See accompanying notes to unaudited condensed consolidated financial statements.

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MONOLITHIC POWER SYSTEMS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY

(In thousands, except per-share amounts)

(Unaudited)

										*Accumulated*
	*Common Stock and*									*Other*			*Total*
	*Additional Paid-in Capital*						*Retained*			*Comprehensive*			*Stockholders’*
Three Months Ended June 30, 2024	*Shares*			*Amount*			*Earnings*			*Loss*			*Equity*
Balance as of April 1, 2024		48,667		$	1,176,382		$	977,724		$	(40,549	)	$	2,113,557
Net income		-			-			100,366			-			100,366
Other comprehensive loss		-			-			-			(3,945	)		(3,945	)
Dividends and dividend equivalents declared ($1.25 per share)		-			-			(61,882	)		-			(61,882	)
Common stock issued under the employee equity incentive plan		37			-			-			-			-
Repurchases of common stock		(6	)		(4,550	)		-			-			(4,550	)
Stock-based compensation expense		-			52,312			-			-			52,312
Balance as of June 30, 2024		48,698		$	1,224,144		$	1,016,208		$	(44,494	)	$	2,195,858

								*Accumulated*
	*Common Stock and*							*Other*			*Total*
	*Additional Paid-in Capital*				*Retained*			*Comprehensive*			*Stockholders’*
Three Months Ended June 30, 2023	*Shares*		*Amount*		*Earnings*			*Loss*			*Equity*
Balance as of April 1, 2023		47,411	$	1,017,131	$	777,075		$	(17,945	)	$	1,776,261
Net income		-		-		99,504			-			99,504
Other comprehensive loss		-		-		-			(25,452	)		(25,452	)
Dividends and dividend equivalents declared ($1.00 per share)		-		-		(49,223	)		-			(49,223	)
Common stock issued under the employee equity incentive plan		200		4		-			-			4
Stock-based compensation expense		-		37,995		-			-			37,995
Balance as of June 30, 2023		47,611	$	1,055,130	$	827,356		$	(43,397	)	$	1,839,089

										*Accumulated*
	*Common Stock and*									*Other*			*Total*
	*Additional Paid-in Capital*						*Retained*			*Comprehensive*			*Stockholders’*
Six Months Ended June 30, 2024	*Shares*			*Amount*			*Earnings*			*Loss*			*Equity*
Balance as of January 1, 2024		48,028		$	1,129,937		$	947,064		$	(27,062	)	$	2,049,939
Net income		-			-			192,907			-			192,907
Other comprehensive loss		-			-			-			(17,432	)		(17,432	)
Dividends and dividend equivalents declared ($2.50 per share)		-			-			(123,763	)		-			(123,763	)
Common stock issued under the employee equity incentive plan		671			-			-			-			-
Common stock issued under the employee stock purchase plan		11			4,606			-			-			4,606
Repurchases of common stock		(12	)		(8,626	)		-			-			(8,626	)
Stock-based compensation expense		-			98,227			-			-			98,227
Balance as of June 30, 2024		48,698		$	1,224,144		$	1,016,208		$	(44,494	)	$	2,195,858

								*Accumulated*
	*Common Stock and*							*Other*			*Total*
	*Additional Paid-in Capital*				*Retained*			*Comprehensive*			*Stockholders’*
Six Months Ended June 30, 2023	*Shares*		*Amount*		*Earnings*			*Loss*			*Equity*
Balance as of January 1, 2023		47,107	$	975,276	$	716,403		$	(23,077	)	$	1,668,602
Net income		-		-		209,306			-			209,306
Other comprehensive loss		-		-		-			(20,320	)		(20,320	)
Dividends and dividend equivalents declared ($2.00 per share)		-		-		(98,353	)		-			(98,353	)
Common stock issued under the employee equity incentive plan		495		1,114		-			-			1,114
Common stock issued under the employee stock purchase plan		9		3,737		-			-			3,737
Stock-based compensation expense		-		75,003		-			-			75,003
Balance as of June 30, 2023		47,611	$	1,055,130	$	827,356		$	(43,397	)	$	1,839,089

See accompanying notes to unaudited condensed consolidated financial statements.

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MONOLITHIC POWER SYSTEMS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands)

(Unaudited)

	*Six Months Ended June 30,*
	*2024*			*2023*
Cash flows from operating activities:
Net income	$	192,907		$	209,306
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		16,942			19,940
Amortization of premium (discount) on available-for-sale securities		(10,040	)		56
Gain on deferred compensation plan investments		(5,285	)		(5,022	)
Gain on sale of equity investments		-			(1,424	)
Deferred taxes, net		(5,821	)		(984	)
Stock-based compensation expense		98,232			75,001
Other		77			-
Changes in operating assets and liabilities:
Accounts receivable		21,951			13,544
Inventories		(42,350	)		19,847
Other assets		60,590			(4,881	)
Accounts payable		30,725			12,653
Accrued compensation and related benefits		8,353			(20,613	)
Income tax liabilities		7,459			(14,802	)
Other accrued liabilities		15,286			6,371
Net cash provided by operating activities		389,026			308,992
Cash flows from investing activities:
Purchases of property and equipment		(47,498	)		(16,681	)
Cash paid for an assumed lease		(18,175	)		-
Purchases of investments		(589,615	)		(211,407	)
Maturities and sales of investments		420,514			232,206
Cash paid for acquisition, net of cash acquired		(33,283	)		-
Contributions to deferred compensation plan, net		(1,309	)		(3,855	)
Net cash provided by (used in) investing activities		(269,366	)		263
Cash flows from financing activities:
Property and equipment purchased on extended payment terms		(2,010	)		(1,192	)
Proceeds from common stock issued under the employee equity incentive plan		-			1,114
Proceeds from common stock issued under the employee stock purchase plan		4,606			3,737
Repurchases of common stock		(8,626	)		-
Dividends and dividend equivalents paid		(117,608	)		(85,863	)
Net cash used in financing activities		(123,638	)		(82,204	)
Effect of change in exchange rates		(6,603	)		(8,696	)
Net increase (decrease) in cash, cash equivalents and restricted cash		(10,581	)		218,355
Cash, cash equivalents and restricted cash, beginning of period		561,181			288,729
Cash, cash equivalents and restricted cash, end of period	$	550,600		$	507,084
Supplemental disclosures for cash flow information:
Cash paid for income taxes, net	$	34,064		$	58,216
Non-cash investing and financing activities:
Liability accrued for property and equipment purchases	$	7,488		$	2,586
Liability accrued for dividends and dividend equivalents	$	62,949		$	51,037

See accompanying notes to unaudited condensed consolidated financial statements.

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MONOLITHIC POWER SYSTEMS, INC.

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

1. BASIS OF PRESENTATION

The accompanying unaudited condensed consolidated financial statements have been prepared by Monolithic Power Systems, Inc. (the “Company” or “MPS”) in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) have been condensed or omitted in accordance with these accounting principles, rules and regulations. The information in this report should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on February 29, 2024.

In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all adjustments (consisting only of normal recurring adjustments) necessary to present fairly the Company’s financial position, results of operations and cash flows for the interim periods presented. The financial statements contained in this Quarterly Report on Form 10-Q are not necessarily indicative of the results that may be expected for the year ending December 31, 2024 or for any other future periods.

Summary of Significant Accounting Policies

There have been no changes to the Company’s significant accounting policies during the three and six months ended June 30, 2024. In addition to those described in the Company’s audited consolidated financial statements included in the Annual Report on Form 10-K for the year ended December 31, 2023, the Company is subject to the following significant accounting policy due to the recent acquisition.

Goodwill and Acquisition-Related Intangible Assets

Goodwill represents the excess of fair value of purchase consideration over fair value of net tangible and identifiable intangible assets acquired as of the date of an acquisition. In-process research and development (“IPR&D”) assets represent the fair value of incomplete research and development (“R&D”) projects that had not reached technological feasibility as of the date of acquisition. IPR&D assets are initially capitalized at fair value as intangible assets with indefinite lives. When IPR&D projects are completed, they are reclassified as amortizable intangible assets and are amortized over their estimated useful lives. Alternatively, if IPR&D projects are abandoned, they are impaired and expensed as R&D costs. Acquisition-related intangible assets with finite lives consist of developed technologies, which are amortized on a straight-line basis over their estimated remaining useful lives. The amortization expense is recorded in cost of revenue in the Condensed Consolidated Statements of Operations.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of revenue and expenses during the reporting period. Significant estimates and assumptions used in these condensed consolidated financial statements primarily include those related to revenue recognition, inventory valuation, valuation of share-based awards, contingencies and income tax valuation allowances. Actual results could differ from these estimates and assumptions, and any such differences may be material to the Company’s condensed consolidated financial statements.

New Accounting Pronouncements Not Yet Adopted as of June 30, 2024

In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures, which aims to improve disclosures regarding a public entity’s reportable segments, primarily through more comprehensive disclosures around significant segment expenses. The standard is effective for annual periods beginning January 1, 2024 and for interim periods beginning January 1, 2025, and should be applied retroactively to all prior periods presented. The Company is evaluating the potential effect that the updated standard will have on its financial statement disclosures.

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which aims to improve an entity’s income tax disclosures around its effective rate reconciliation, income taxes paid, disaggregation of income before income taxes and income tax expense. The guidance will be effective for annual periods beginning January 1, 2025. The standard should be applied prospectively but retrospective application is permitted. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial statements.

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2. REVENUE RECOGNITION

Revenue from Product Sales

The Company generates revenue primarily from product sales, which include assembled and tested integrated circuits (“ICs”), power modules as well as dies in wafer form. These product sales accounted for 99% of the Company’s total revenue for each of the three and six months ended June 30, 2024 and 2023. The remaining revenue primarily includes royalty revenue from licensing arrangements and revenue from wafer testing services performed for third parties. See Note 8 for the disaggregation of the Company’s revenue by geographic region and by product family.

The Company sells its products primarily through third-party distributors, value-added resellers, original equipment manufacturers (“OEMs”), original design manufacturers (“ODMs”) and electronic manufacturing service (“EMS”) providers. For the three months ended June 30, 2024 and 2023, 90% and 80%, respectively, of the Company’s product sales were made through distribution arrangements. For the six months ended June 30, 2024 and 2023, 87% and 80%, respectively, of the Company’s product sales were made through distribution arrangements. These distribution arrangements contain enforceable rights and obligations specific to those distributors and not the end customers. Purchase orders, which are generally governed by sales agreements or the Company’s standard terms of sale, set the final terms for unit price, quantity, shipping and payment agreed between the Company and the customer. The Company considers purchase orders to be the contracts with customers. The unit price as stated on the purchase orders is considered the observable, stand-alone selling price for the arrangements.

The Company recognizes revenue when it satisfies a performance obligation by transferring control of the promised goods or services to its customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. The Company excludes taxes assessed by government authorities, such as sales taxes, from revenue.

Product sales consist of a single performance obligation that the Company satisfies at a point in time. The Company recognizes product revenue from distributors and direct end customers when the following events have occurred: (a) the Company has transferred physical possession of the products, (b) the Company has a present right to payment, (c) the customer has legal title to the products, and (d) the customer bears significant risks and rewards of ownership of the products. In accordance with the shipping terms specified in the contracts, these criteria are generally met when the products are shipped from the Company’s facilities (such as the “Ex Works” shipping term) or delivered to the customers’ locations (such as the “Delivered Duty Paid” shipping term).

Under certain consignment agreements, the Company recognizes revenue when the customers consume the products from the consigned inventory locations, at which time control transfers to the customers and the Company issues invoices.

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Variable Consideration

The Company accounts for price adjustments and stock rotation rights as variable consideration that reduces the transaction price and recognizes that reduction in the same period the associated revenue is recognized. Certain U.S.-based distributors have price adjustment rights when they sell the Company’s products to their end customers at a price that is lower than the distribution price invoiced by the Company. When the Company receives claims from the distributors that products have been sold to the end customers at the lower price, the Company issues the distributors credit memos for the price adjustments. The Company estimates the price adjustments using the expected value method based on an analysis of historical claims, at both the distributor and product level, as well as an assessment of any known trends of product sales mix. Other U.S. distributors and non-U.S. distributors do not have price adjustment rights. The Company records a credit against accounts receivable for the estimated price adjustments, with a corresponding reduction to revenue.

Certain distributors have limited stock rotation rights that permit the return of a small percentage of the previous six months’ purchases in accordance with the contract terms. The Company estimates the stock rotation returns using the expected value method based on an analysis of historical returns, and the current level of inventory in the distribution channel. The Company records a liability for the stock rotation reserve, with a corresponding reduction to revenue. In addition, the Company recognizes an asset for product returns which represents the right to recover products from the customers related to stock rotations, with a corresponding reduction to cost of revenue.

Contract Balances

Accounts Receivable:

The Company records a receivable when it has an unconditional right to receive consideration after the performance obligations are satisfied. The Company’s accounts receivables are short-term, with standard payment terms generally ranging from 30 to 90 days. The Company does not require its customers to provide collateral to support accounts receivable. The Company assesses collectability by reviewing accounts receivable on a customer-by-customer basis. To manage credit risk, management performs ongoing credit evaluations of the customers’ financial condition, monitors payment performance, and assesses current economic conditions, as well as reasonable and supportable forecasts of future economic conditions, that may affect collectability of the outstanding receivables. For certain customers, the Company requires standby letters of credit or advance payments prior to shipments of goods. The Company did not recognize any write-offs of accounts receivable or record any allowance for credit losses for the periods presented.

Contract Liabilities:

For customers without credit terms, the Company requires cash payments two weeks before the products are scheduled to be shipped to the customers. The Company records these payments received in advance of performance as customer prepayments within current accrued liabilities. As of June 30, 2024 and December 31, 2023, customer prepayments totaled $5.6 million and $2.8 million, respectively. The increase in the customer prepayment balance for the six months ended June 30, 2024 resulted from an increase in unfulfilled customer orders for which the Company had received payments.

Practical Expedients

The Company has elected the practical expedient to expense sales commissions as incurred because the amortization period would have been one year or less.

The Company’s standard payment terms generally require customers to pay 30 to 90 days after the Company satisfies the performance obligations. For those customers who are required to pay in advance, the Company satisfies the performance obligations generally within a quarter. For these reasons, the Company has elected not to determine whether contracts with customers contain significant financing components.

The Company’s unsatisfied performance obligations primarily include products held in consignment arrangements and customer purchase orders for products that the Company has not yet shipped. Because the Company expects to fulfill these performance obligations within one year, the Company has elected not to disclose the amount of these remaining performance obligations.

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3. STOCK-BASED COMPENSATION

2014 Equity Incentive Plan

In April 2013, the Board of Directors adopted the Company’s 2014 Equity Incentive Plan (the “2014 Plan”), which the Company’s stockholders approved in June 2013. In October 2014, the Board of Directors approved certain amendments to the 2014 Plan. The amended 2014 Plan became effective on November 13, 2014, and provided for the issuance of up to 5.5 million shares. In April 2020, the Board of Directors further amended and restated the amended 2014 Plan (the “Amended and Restated 2014 Plan”), which the Company’s stockholders approved in June 2020. The Amended and Restated 2014 Plan became effective on June 11, 2020, and provides for the issuance of up to 10.5 million shares. The Amended and Restated 2014 Plan will cease being available for new awards on June 11, 2030. As of June 30, 2024, 3.9 million shares remained available for future issuance under the Amended and Restated 2014 Plan.

Stock-Based Compensation Expense

The Company recognized stock-based compensation expenses as follows (in thousands):

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Cost of revenue	$	1,611	$	1,150	$	3,009	$	2,297
Research and development		11,682		9,313		22,129		17,927
Selling, general and administrative (“SG&A”)		39,013		27,529		73,094		54,777
Total stock-based compensation expense	$	52,306	$	37,992	$	98,232	$	75,001
Tax benefit related to stock-based compensation ⁽¹⁾	$	798	$	663	$	1,506	$	1,086

(1)

Amount reflects the tax benefit related to stock-based compensation recorded for equity awards that are expected to generate tax deductions when they vest in future periods. Equity awards granted to the Company’s executive officers are subject to the tax deduction limitations set by Section 162(m) of the Internal Revenue Code.

Restricted Stock Units (“RSUs”)

The Company’s RSUs include time-based RSUs, RSUs with performance conditions (“PSUs”), RSUs with market conditions (“MSUs”), and RSUs with both market and performance conditions (“MPSUs”). Vesting of awards with performance conditions or market conditions is subject to the achievement of pre-determined performance or market goals and the approval of such achievement by the Compensation Committee of the Board of Directors (the “Compensation Committee”). All awards include service conditions which require continued employment with or services to the Company.

A summary of RSU activity is presented in the table below (in thousands, except per-share amounts):

	*Time-Based RSUs*					*PSUs and MPSUs*						*MSUs*					*Total*
				*Weighted-*						*Weighted-*					*Weighted-*					*Weighted-*
				*Average*						*Average*					*Average*					*Average*
				*Grant Date*						*Grant Date*					*Grant Date*					*Grant Date*
	*Number of*			*Fair Value*		*Number of*				*Fair Value*		*Number of*			*Fair Value*		*Number of*			*Fair Value*
	*Shares*			*Per Share*		*Shares*				*Per Share*		*Shares*			*Per Share*		*Shares*			*Per Share*
Outstanding at January 1, 2024		102		$	411.11		482			$	397.77		1,502		$	152.89		2,086		$	222.04
Granted		30		$	635.67		344		⁽¹⁾	$	593.33		-		$	-		374		$	596.68
Vested		(31	)	$	363.82		(77	)		$	307.93		(563	)	$	68.48		(671	)	$	109.62
Forfeited		(3	)	$	465.22		(1	)		$	396.40		(1	)	$	270.15		(5	)	$	412.40
Outstanding at June 30, 2024		98		$	493.16		748			$	496.84		938		$	203.33		1,784		$	342.19

(1)	Amount reflects the number of awards that may ultimately be earned based on management’s probability assessment of the achievement of performance conditions at each reporting period.

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The intrinsic value related to vested RSUs was $25.5 million and $98.1 million for the three months ended June 30, 2024 and 2023, respectively. The intrinsic value related to vested RSUs was $428.6 million and $239.7 million for the six months ended June 30, 2024 and 2023, respectively. As of June 30, 2024, the total intrinsic value of all outstanding RSUs was $1.4 billion, based on the closing stock price of $821.68. As of June 30, 2024, unamortized compensation expense related to all outstanding RSUs was $350.8 million with a weighted-average remaining recognition period of approximately two years.

Time-Based RSUs:

For the six months ended June 30, 2024, the Compensation Committee granted 30,000 RSUs with service conditions to non-executive employees and non-employee directors. The RSUs generally vest over four years for employees and one year for directors, subject to continued service with the Company.

2024 PSUs:

In February 2024, the Compensation Committee granted 50,000 PSUs to the executive officers, which represent a target number of shares that can be earned based on the degree of achievement of three sets of performance goals (“2024 Executive PSUs”). For the first goal, the executive officers can earn up to 300% of the target number of the 2024 Executive PSUs based on the achievement of the Company’s average three-year (2024 through 2026) revenue growth rate in excess of the analog industry’s average three-year revenue growth rate as published by the Semiconductor Industry Association (the “SIA”). For the second goal, the executive officers can earn an additional 100% of the target number of the 2024 Executive PSUs if the Company achieves a reduction in 2026 of 25% global combined Scope 1 and Scope 2 greenhouse gas emissions against the 2022 baseline. For the third goal, the executive officers can earn 50% of the target number of the 2024 Executive PSUs if more than one-third of the Company’s total 2026 revenue in the automotive market is generated from Electronic Vehicle (“EV”) automakers. In addition, for the third goal, the executive officers can earn 50% of the target number of the 2024 Executive PSUs if total 2026 revenue from products enabling EV powertrains and EV 48V systems grows to 200% of the 2023 baseline. For the first goal, a percentage of the 2024 Executive PSUs will fully vest on December 31, 2026, depending on the degree to which the pre-determined goal is met during the performance period. The 2024 Executive PSUs related to the second and the third goal will fully vest on December 31, 2026 if the pre-determined goals are met during the performance period. Assuming the achievement of the highest level of the performance goals, the total stock-based compensation cost for the 2024 Executive PSUs will be $154.3 million.

In February 2024, the Compensation Committee granted 11,000 PSUs to certain non-executive employees, which represent a target number of shares that can be earned based on the degree of achievement of the Company’s 2025 revenue goals for certain regions or product line divisions, or based on the degree of achievement of the Company’s average two-year (2024 and 2025) revenue growth rate compared against the analog industry’s average two-year revenue growth rate as published by the SIA (“2024 Non-Executive PSUs”). The maximum number of shares that an employee can earn is either 200% or 300% of the target number of the 2024 Non-Executive PSUs, depending on the job classification of the employee. 50% of the 2024 Non-Executive PSUs will vest in the first quarter of 2026 depending on the degree to which the pre-determined goals are met during the performance period. The remaining 2024 Non-Executive PSUs will vest over the following two years on a quarterly basis. Assuming the achievement of the highest level of performance goals, the total stock-based compensation cost for the 2024 Non-Executive PSUs will be $17.7 million.

The 2024 Executive PSUs and the 2024 Non-Executive PSUs contain a purchase price feature, which requires the employees to pay the Company $30 per share upon vesting of the shares. The $30 purchase price requirement is deemed satisfied and waived if the Company’s stock price on the last trading day of the performance period is $30 higher than the grant date stock price of $632.98. The Company determined the grant date fair value of the 2024 Executive PSUs and the 2024 Non-Executive PSUs using a Monte Carlo simulation model with the following assumptions: stock price of $632.98, simulation term of three years, expected volatility of 49.4%, risk-free interest rate of 4.1%, and expected dividend yield of 0.8%. There is no illiquidity discount because the awards do not contain any post-vesting sales restrictions.

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2004 Employee Stock Purchase Plan (as amended and restated, the “2004 ESPP”)

On August 16, 2023, the 2004 ESPP was amended and restated to, among other changes, provide for the issuance of up to 4.4 million shares of the Company’s common stock. The 2004 ESPP will expire on August 16, 2038.

No shares were issued under the 2004 ESPP for the three months ended June 30, 2024 and 2023. For the six months ended June 30, 2024 and 2023, 11,000 and 9,000 shares were issued under the 2004 ESPP, respectively. As of June 30, 2024, 4.4 million shares were available for future issuance under the 2004 ESPP.

The intrinsic value of the shares issued was $3.5 million and $0.7 million for the six months ended June 30, 2024 and 2023, respectively. As of June 30, 2024, the unamortized expense was $0.4 million, which will be recognized through the third quarter of 2024. The Black-Scholes model was used to value the employee stock purchase rights with the following weighted-average assumptions:

	*Six Months Ended June 30,*
	*2024*			*2023*
Expected term (in years)		0.5			0.5
Expected volatility		42.4	%		55.8	%
Risk-free interest rate		5.3	%		5.0	%
Dividend yield		0.7	%		0.8	%

Cash proceeds from the shares issued under the 2004 ESPP were $4.6 million and $3.7 million for the six months ended June 30, 2024 and 2023, respectively.

4. ACQUISITION

On January 3, 2024 (the “Acquisition Date”), the Company acquired 100% of the outstanding capital stock of Axign B.V. (“Axign”), a Dutch company that designs and develops class-D audio ICs, targeting applications ranging from portable consumer speakers to automotive and professional-grade multi-speaker systems. Commencing on the Acquisition Date, Axign became a wholly-owned subsidiary of the Company and its results of operations have been included in the Company’s consolidated financial statements.

Purchase Consideration

The purchase consideration was $33.4 million in cash. Cash paid at the Acquisition Date included $3.8 million that is being held in an escrow account for a one-year period as recourse in the event of a breach of Axign’s representations and warranties.

In connection with the acquisition, the Company incurred $0.4 million in transaction costs that were expensed as incurred and included in selling, general and administrative expenses in the Condensed Consolidated Statements of Operations.

Purchase Price Allocation

The purchase price allocation for Axign is as follows (in thousands):

Inventory	$	720
Other tangible assets acquired, net of liabilities assumed		1,487
Intangible assets:
Developed technology		9,184
IPR&D		2,147
Total identifiable net assets acquired		13,538
Goodwill		19,860
Total net assets acquired	$	33,398

The intangible asset acquired with a finite life includes the core developed technology with an estimated remaining useful life of eight years. The acquired intangible asset with an indefinite life includes an incomplete R&D project that had not reached technological feasibility as of the Acquisition Date. The fair values of the developed technology and the IPR&D were determined using the income approach.

The goodwill arising from the acquisition was primarily attributed to the assembled workforce and synergies that are anticipated to enable the Company to develop solutions with lower power consumption in the consumer and automotive markets using Axign’s digital feedback technology. The goodwill is not expected to be deductible for tax purposes.

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5. BALANCE SHEET COMPONENTS

Inventories

Inventories consist of the following (in thousands):

	*June 30,*		*December 31,*
	*2024*		*2023*
Raw materials	$	93,435	$	118,917
Work in process		164,116		112,750
Finished goods		169,200		152,035
Total	$	426,751	$	383,702

Other Current Assets

Other current assets consist of the following (in thousands):

	*June 30,*		*December 31,*
	*2024*		*2023*
Prepaid wafer purchases	$	60,000	$	-
Prepaid expenses		27,570		28,964
RSU tax withholding proceeds receivable		71		20,141
Other receivables		-		50,000
Restricted cash		-		33,204
Other		17,906		15,154
Total	$	105,547	$	147,463

The Company held $60 million in prepaid wafer purchases as of June 30, 2024 and $50 million in other receivables as of December 31, 2023 related to deposits made to a supplier under a long-term wafer supply agreement. See Note 9 for details about the supply agreement. The restricted cash included in other current assets as of December 31, 2023 was related to preliminary purchase consideration held in a trust account in connection with the Company’s acquisition of Axign and was paid in January 2024. See Note 4 for further details.

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Other Long-Term Assets

Other long-term assets consist of the following (in thousands):

	*June 30,*		*December 31,*
	*2024*		*2023*
Deferred compensation plan assets	$	84,975	$	78,381
Prepaid wafer purchases		60,000		120,000
Operating lease right-of-use (“ROU”) and related assets		33,681		8,355
Other		5,210		4,541
Total	$	183,866	$	211,277

Prepaid wafer purchases relate to a deposit made to a supplier under a long-term wafer supply agreement. See Note 9 for details about the supply agreement. The operating lease ROU and related assets as of June 30, 2024 includes a fair value measurement related to favorable market terms on a building lease.

Other Accrued Liabilities

Other accrued liabilities consist of the following (in thousands):

	*June 30,*		*December 31,*
	*2024*		*2023*
Dividends and dividend equivalents	$	62,524	$	57,697
Stock rotation and sales returns		21,716		18,843
Warranty		14,702		16,906
Customer prepayments		5,564		2,792
Accrued legal expenses		4,249		1,277
Income tax payable		9,641		8,063
Other		12,952		10,213
Total	$	131,348	$	115,791

Other Long-Term Liabilities

Other long-term liabilities consist of the following (in thousands):

	*June 30,*		*December 31,*
	*2024*		*2023*
Deferred compensation plan liabilities	$	80,115	$	80,903
Operating lease liabilities		13,045		5,565
Dividend equivalents		3,515		2,187
Total	$	96,675	$	88,655

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6. LEASES

Lessee

The Company has operating leases primarily for administrative, sales and marketing offices, manufacturing operations and R&D facilities, employee housing units and certain equipment. These leases have remaining lease terms from less than one year to 20 years. Some of these leases include options to renew the lease term for up to five years or on a month-to-month basis. The Company does not have finance lease arrangements.

The following table summarizes the balances of operating lease ROU assets and liabilities (in thousands):

		*June 30,*		*December 31,*
	*Financial Statement Line Item*	*2024*		*2023*
Operating lease ROU assets	Other long-term assets	$	15,956	$	8,355

Operating lease liabilities	Other accrued liabilities	$	2,446	$	2,303
	Other long-term liabilities	$	13,045	$	5,565

The following tables summarize certain information related to the leases (in thousands, except percentages and years):

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Lease costs:
Operating lease costs	$	1,014	$	759	$	1,911	$	1,475
Other		648		554		1,198		1,092
Total lease costs	$	1,662	$	1,313	$	3,109	$	2,567

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows for operating leases	$	1,027	$	774	$	1,700	$	1,638
ROU assets obtained in exchange for new operating lease liabilities	$	7,809	$	290	$	9,271	$	4,835

	*June 30,*			*December 31,*
	*2024*			*2023*
Weighted-average remaining lease term (in years)		12.1			4.7
Weighted-average discount rate		5.4	%		4.3	%

As of June 30, 2024, the maturities of the lease liabilities were as follows (in thousands):

2024 (remaining six months)	$	1,617
2025		2,997
2026		2,249
2027		2,012
2028		1,380
Thereafter		12,534
Total remaining lease payments		22,789
Less: imputed interest		(7,298	)
Total lease liabilities	$	15,491

As of June 30, 2024, operating leases that have not yet commenced are not material.

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Lessor

The Company owns certain office buildings and leases a portion of these properties to third parties under arrangements that are classified as operating leases. These leases have remaining lease terms ranging from less than one year to five years. Some of these leases include a tenant option to renew the lease term for up to five years.

For the three months ended June 30, 2024 and 2023, income related to lease payments was $0.2 million and $0.3 million, respectively. For the six months ended June 30, 2024 and 2023, income related to lease payments was $0.4 million and $0.8 million, respectively. As of June 30, 2024, future income related to lease payments was as follows (in thousands):

2024 (remaining six months)	$	525
2025		578
2026		402
2027		373
2028		384
Thereafter		129
Total	$	2,391

7. NET INCOME PER SHARE

Basic net income per share is computed by dividing net income by the weighted-average number of shares of common stock outstanding for the period. Diluted net income per share reflects the potential dilution that would occur if outstanding securities or other contracts to issue common stock were exercised or converted into shares of common stock, and calculated using the treasury stock method. Contingently issuable shares, including equity awards with performance conditions or market conditions, are considered outstanding shares of common stock and included in the basic net income per share as of the date that all necessary conditions to earn the awards have been satisfied. Prior to the end of the contingency period, the number of contingently issuable shares included in the diluted net income per share is based on the number of shares, if any, that would be issuable under the terms of the arrangement at the end of the reporting period.

The Company’s RSUs contain forfeitable rights to receive cash dividend equivalents, which are accumulated and paid to the employees when the underlying RSUs vest. Dividend equivalents accumulated on the underlying RSUs are forfeited if the employees do not fulfill the requisite service requirement and, as a result, the awards do not vest. Accordingly, these awards are not treated as participating securities in the net income per share calculation.

The following table sets forth the computation of basic and diluted net income per share (in thousands, except per-share amounts):

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Numerator:
Net income	$	100,366	$	99,504	$	192,907	$	209,306

Denominator:
Weighted-average outstanding shares — basic		48,687		47,489		48,660		47,361
Effect of dilutive securities		258		1,267		275		1,344
Weighted-average outstanding shares — diluted		48,945		48,756		48,935		48,705

Net income per share:
Basic	$	2.06	$	2.10	$	3.96	$	4.42
Diluted	$	2.05	$	2.04	$	3.94	$	4.30

Anti-dilutive common stock equivalents were not material in any of the periods presented.

Stock Repurchase Program

In October 2023, the Board of Directors approved a new stock repurchase program authorizing the Company to repurchase up to $640.0 million in the aggregate of its common stock through October 29, 2026. Shares are retired upon repurchase. The Company repurchased 6,300 and 12,400 shares of its common stock for an aggregate purchase price of $4.5 million and $8.6 million during the three and six months ended June 30, 2024, respectively.

Stock repurchased under the program may be made through open market repurchases, privately negotiated transactions or other structures in accordance with applicable state and federal securities laws, at times and in amounts as management deems appropriate. The timing and the number of any repurchased common stock will be determined by the Company’s management based on its evaluation of market conditions, legal requirements, share price, and other factors. The repurchase program does not obligate the Company to purchase any particular number of shares, and may be suspended, modified, or discontinued at any time without prior notice.

The U.S. Inflation Reduction Act of 2022 requires a 1% excise tax based on the value of certain stock repurchases in excess of stock issued for employee compensation made after December 31, 2022. This provision did not have an impact on the Company’s condensed consolidated financial statements for the three and six months ended June 30, 2024.

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8. SEGMENT, SIGNIFICANT CUSTOMERS AND GEOGRAPHIC INFORMATION

The Company operates in one reportable segment that includes the design, development, marketing and sale of high-performance, semiconductor-based power electronics solutions for the enterprise data, storage and computing, automotive, communications, consumer and industrial markets. The Company’s chief operating decision maker is its Chief Executive Officer, who reviews financial information presented on a consolidated basis for purposes of allocating resources and evaluating financial performance. The Company derives a majority of its revenue from sales to customers located outside North America, with geographic revenue based on the customers’ ship-to locations.

The Company sells its products primarily to third-party distributors and value-added resellers, and directly to OEMs, ODMs and EMS providers. The following table summarizes those customers with sales equal to 10% or more of the Company’s total revenue:

	Three Months Ended June 30,						Six Months Ended June 30,
Customer	2024			2023			2024			2023
Distributor A		38	%		22	%		40	%		21	%
Distributor B		17	%		20	%		15	%		21	%
Distributor C		*			11	%		*			10	%

The Company’s agreements with these third-party customers were made in the ordinary course of business and may be terminated with or without cause by these customers with advance notice. Although the Company may experience a short-term disruption in the distribution of its products and a short-term decline in revenue if its agreement with any of the distributors were terminated, the Company believes that such termination would not have a material adverse effect on its financial statements because it would be able to engage alternative distributors, resellers and other distribution channels to deliver its products to end customers within a short period following any termination of the agreement with a distributor.

The following table summarizes those customers with accounts receivable equal to 10% or more of the Company’s total accounts receivable:

	*June 30,*			*December 31,*
Customer	*2024*			*2023*
Distributor A		41	%		42	%
Distributor B		24	%		13	%
Distributor C		*			10	%

* Represents less than 10%

The following is a summary of revenue by geographic region (in thousands):

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
Country or Region	*2024*		*2023*		*2024*		*2023*
China	$	282,514	$	216,172	$	545,554	$	441,224
Taiwan		127,396		70,212		227,846		119,045
South Korea		39,513		40,669		75,050		86,349
Europe		19,105		36,348		36,847		79,451
United States		13,927		27,571		28,747		58,588
Southeast Asia		11,352		21,708		24,591		48,140
Japan		13,552		28,288		26,500		59,103
Other		72		160		181		293
Total	$	507,431	$	441,128	$	965,316	$	892,193

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In the second quarter of 2024, the Company reclassified certain products in its product families. The prior periods in the table below have been updated to conform with the new methodology.

The following is a summary of revenue by product family (in thousands):

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
Product Family	*2024*		*2023*		*2024*		*2023*
Direct Current (“DC”) to DC	$	501,302	$	418,175	$	947,367	$	843,356
Lighting Control		6,129		22,953		17,949		48,837
Total	$	507,431	$	441,128	$	965,316	$	892,193

The following is a summary of long-lived assets by geographic region (in thousands):

	*June 30,*		*December 31,*
Country	*2024*		*2023*
China	$	207,614	$	184,685
United States		124,000		119,430
Taiwan		37,071		39,419
Other		31,849		25,418
Total	$	400,534	$	368,952

9. COMMITMENTS AND CONTINGENCIES

Product Warranties

The Company generally provides either a one- or two-year warranty against defects in materials and workmanship and will repair the products, provide replacements at no charge to customers or issue a refund. As they are considered assurance-type warranties, the Company does not account for them as separate performance obligations. Warranty reserve requirements are generally based on a specific assessment of the products sold with warranties when a customer asserts a claim for warranty or for a product defect.

The changes in warranty reserves are as follows (in thousands):

	*Three Months Ended June 30,*						*Six Months Ended June 30,*
	*2024*			*2023*			*2024*			*2023*
Balance at beginning of period	$	12,873		$	19,726		$	16,906		$	24,082
Warranties issued		2,225			580			2,325			942
Repairs, replacement and refund		(116	)		(1,581	)		(4,130	)		(2,253	)
Changes in liability for pre-existing warranties		(280	)		(1,071	)		(399	)		(5,117	)
Balance at end of period	$	14,702		$	17,654		$	14,702		$	17,654

Changes in liability for pre-existing warranties result from changes in estimates for warranties issued in prior periods.

Purchase Commitments

The Company has outstanding purchase obligations with its suppliers and other parties that require the purchases of goods or services. The purchase obligations primarily consist of wafer and other inventory purchases, assembly and other manufacturing services, construction of manufacturing and R&D facilities, purchases of production and other equipment, and license arrangements.

In May 2022, the Company entered into a long-term supply agreement in order to secure manufacturing production capacity for silicon wafers over a four-year period. As of June 30, 2024, the Company had remaining prepayments under this agreement of $120.0 million, of which $60.0 million was classified as short-term.

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Total estimated future unconditional purchase commitments to all suppliers and other parties, net of the $120.0 million prepayment, as of June 30, 2024 were as follows (in thousands):

2024 (remaining six months)	$	151,590
2025		388,949
2026		1,572
2027		29,476
Total	$	571,587

Litigation

The Company is a party to actions and proceedings in the ordinary course of business, including challenges to the enforceability or validity of its intellectual property, claims that the Company’s products infringe on the intellectual property rights of others, and employment matters. The Company may also be subject to litigation initiated by its stockholders. These proceedings often involve complex questions of fact and law and may require the expenditure of significant funds and the diversion of other resources to prosecute and defend. The Company defends itself vigorously against any such claims. As of June 30, 2024, there were no material pending legal proceedings to which the Company was a party.

10. CASH, CASH EQUIVALENTS, INVESTMENTS AND RESTRICTED CASH

The following is a summary of the Company’s cash, cash equivalents and debt investments (in thousands):

	*June 30,*		*December 31,*
	*2024*		*2023*
Cash	$	357,743	$	392,329
Money market funds		192,732		135,514
Certificates of deposit		165,120		127,123
Corporate debt securities		22,729		95,101
U.S. treasuries and government agency bonds		568,921		358,409
Auction-rate securities backed by student-loan notes		345		567
Total	$	1,307,590	$	1,109,043

	*June 30,*		*December 31,*
	*2024*		*2023*
Reported as:
Cash and cash equivalents	$	550,475	$	527,843
Short-term investments		756,770		580,633
Investment within other long-term assets		345		567
Total	$	1,307,590	$	1,109,043

The following table summarizes the contractual maturities of the short-term and long-term available-for-sale investments as of June 30, 2024 (in thousands):

	*Amortized Cost*		*Fair Value*
Due in less than 1 year	$	722,601	$	721,901
Due in 1 - 5 years		34,969		34,869
Due in greater than 5 years		350		345
Total	$	757,920	$	757,115

Gross realized gains and losses recognized on the sales of available-for-sale investments were not material for the periods presented.

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The following tables summarize the unrealized gain and loss positions related to the available-for-sale investments (in thousands):

	*June 30, 2024*
	*Amortized Cost*		*Unrealized Gains*		*Unrealized Losses*			*Fair Value*
Money market funds	$	192,732	$	-	$	-		$	192,732
Certificates of deposit		165,120		-		-			165,120
Corporate debt securities		23,285		1		(557	)		22,729
U.S. treasuries and government agency bonds		569,165		5		(249	)		568,921
Auction-rate securities backed by student-loan notes		350		-		(5	)		345
Total	$	950,652	$	6	$	(811	)	$	949,847

	*December 31, 2023*
	*Amortized Cost*		*Unrealized Gains*		*Unrealized Losses*			*Fair Value*
Money market funds	$	135,514	$	-	$	-		$	135,514
Certificates of deposit		127,123		-		-			127,123
Corporate debt securities		96,636		4		(1,539	)		95,101
U.S. treasuries and government agency bonds		358,177		327		(95	)		358,409
Auction-rate securities backed by student-loan notes		574		-		(7	)		567
Total	$	718,024	$	331	$	(1,641	)	$	716,714

The following tables present information about the available-for-sale investments that had been in a continuous unrealized loss position for less than 12 months and for greater than 12 months (in thousands):

	*June 30, 2024*
	*Less than 12 Months*					*Greater than 12 Months*					*Total*
	*Fair Value*		*Unrealized Losses*			*Fair Value*		*Unrealized Losses*			*Fair Value*		*Unrealized Losses*
Corporate debt securities	$	-	$	-		$	22,278	$	(557	)	$	22,278	$	(557	)
U.S. treasuries and government agency bonds		474,947		(214	)		17,351		(35	)		492,298		(249	)
Auction-rate securities backed by student-loan notes		-		-			345		(5	)		345		(5	)
Total	$	474,947	$	(214	)	$	39,974	$	(597	)	$	514,921	$	(811	)

	*December 31, 2023*
	*Less than 12 Months*					*Greater than 12 Months*					*Total*
	*Fair Value*		*Unrealized Losses*			*Fair Value*		*Unrealized Losses*			*Fair Value*		*Unrealized Losses*
Corporate debt securities	$	20,792	$	(19	)	$	70,806	$	(1,520	)	$	91,598	$	(1,539	)
U.S. treasuries and government agency bonds		97,599		(95	)		-		-			97,599		(95	)
Auction-rate securities backed by student-loan notes		-		-			567		(7	)		567		(7	)
Total	$	118,391	$	(114	)	$	71,373	$	(1,527	)	$	189,764	$	(1,641	)

An impairment exists when the fair value of an investment is less than its amortized cost basis. As of June 30, 2024 and December 31, 2023, the Company did not consider the impairment of its investments to be a result of credit losses. The Company typically invests in highly rated securities, with the primary objective of minimizing the potential risk of principal loss. The Company’s investment policy generally requires securities to be investment grade and limits the amount of credit exposure to any one issuer. When evaluating a debt security for impairment, management reviews factors such as the Company’s intent to sell, or whether it will more likely than not be required to sell, the security before recovery of its amortized cost basis, the extent to which the fair value of the security is less than its cost, the financial condition of the issuer and the credit quality of the investment.

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Restricted Cash

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported on the Condensed Consolidated Balance Sheets to the amounts reported on the Condensed Consolidated Statements of Cash Flows (in thousands):

	*June 30,*		*December 31,*
	*2024*		*2023*
Cash and cash equivalents	$	550,475	$	527,843
Restricted cash included in other current assets		-		33,204
Restricted cash included in other long-term assets		125		134
Total cash, cash equivalents and restricted cash reported on the Condensed Consolidated Statements of Cash Flows	$	550,600	$	561,181

The restricted cash included in other current assets as of December 31, 2023 was related to preliminary purchase consideration held in a trust account in connection with the Company’s acquisition of Axign and was paid in January 2024. See Note 4 for additional information. As of June 30, 2024 and December 31, 2023, restricted cash included in other long-term assets was related to a security deposit that is set aside in a bank account and cannot be withdrawn by the Company under the terms of a lease agreement. The restriction will end upon the expiration of the lease.

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11. FAIR VALUE MEASUREMENTS

Fair Value Hierarchy

The Company has estimated the fair value of its financial assets by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement:

●	Level 1 —includes instruments with quoted prices in active markets for identical assets.
●	Level 2 —includes instruments for which the valuations are based upon quoted market prices in active markets involving similar assets or inputs other than quoted prices that are observable for the assets. The market inputs used to value these instruments generally consist of market yields, recently executed transactions, broker/dealer quotes or alternative pricing sources with reasonable levels of price transparency. Pricing sources may include industry standard data providers, security master files from large financial institutions, and other third-party sources used to determine a daily market value.
●	Level 3 —includes instruments for which the valuations are based on inputs that are unobservable and significant to the overall fair value measurement.

Financial Assets Measured at Fair Value on a Recurring Basis

The following tables summarize the fair value of the Company’s financial assets measured on a recurring basis (in thousands):

	*June 30, 2024*
	*Total*		*Level 1*		*Level 2*		*Level 3*
Money market funds	$	192,732	$	192,732	$	-	$	-
Certificates of deposit		165,120		-		165,120		-
Corporate debt securities		22,729		-		22,729		-
U.S. treasuries and government agency bonds		568,921		-		568,921		-
Auction-rate securities backed by student-loan notes		345		-		-		345
Mutual funds and money market funds under deferred compensation plan		58,928		58,928		-		-
Total	$	1,008,775	$	251,660	$	756,770	$	345

	*December 31, 2023*
	*Total*		*Level 1*		*Level 2*		*Level 3*
Money market funds	$	135,514	$	135,514	$	-	$	-
Certificates of deposit		127,123		-		127,123		-
Corporate debt securities		95,101		-		95,101		-
U.S. treasuries and government agency bonds		358,409		-		358,409		-
Auction-rate securities backed by student-loan notes		567		-		-		567
Mutual funds and money market funds under deferred compensation plan		54,836		54,836		-		-
Total	$	771,550	$	190,350	$	580,633	$	567

Redemptions and changes in the fair value of the auction-rate securities classified as Level 3 assets were not material for the periods presented.

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12. DEFERRED COMPENSATION PLAN

The following table summarizes the deferred compensation plan balances on the Condensed Consolidated Balance Sheets (in thousands):

	*June 30,*		*December 31,*
	*2024*		*2023*
Deferred compensation plan asset components:
Cash surrender value of corporate-owned life insurance policies	$	26,047	$	23,545
Fair value of mutual funds and money market funds		58,928		54,836
Total	$	84,975	$	78,381

Deferred compensation plan assets reported in:
Other long-term assets	$	84,975	$	78,381

Deferred compensation plan liabilities reported in:
Accrued compensation and related benefits (short-term)	$	7,534	$	384
Other long-term liabilities		80,115		80,903
Total	$	87,649	$	81,287

13. OTHER INCOME, NET

The components of other income, net, are as follows (in thousands):

	*Three Months Ended June 30,*					*Six Months Ended June 30,*
	*2024*			*2023*		*2024*			*2023*
Interest income	$	6,630		$	5,965	$	13,544		$	10,773
Amortization of discount (premium) on available-for-sale securities		5,917			204		10,040			(56	)
Other		(5,035	)		374		(6,532	)		1,123
Total	$	7,512		$	6,543	$	17,052		$	11,840

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14. INCOME TAXES

The income tax provision or benefit for interim periods is generally determined using an estimate of the Company’s annual effective tax rate and adjusted for discrete items, if any, in the relevant period. Each quarter the estimate of the annual effective tax rate is updated, and if the Company’s estimated tax rate changes, a cumulative adjustment is made.

The income tax expense for the three months ended June 30, 2024 was $23.7 million, or 19.1% of pre-tax income. The income tax expense for the six months ended June 30, 2024 was $36.2 million, or 15.8% of pre-tax income. The effective tax rates were lower than the federal statutory rate of 21% primarily due to foreign income from the Company’s subsidiaries in Bermuda and China being taxed at lower statutory tax rates, and excess tax benefits from stock-based compensation. The decrease in the effective tax rates relative to the federal statutory rate was partially offset by the inclusion of the global intangible low-taxed income (“GILTI”) tax.

The income tax expense for the three months ended June 30, 2023 was $19.4 million, or 16.3% of pre-tax income. The income tax expense for the six months ended June 30, 2023 was $39.1 million, or 15.8% of pre-tax income. The effective tax rates were lower than the federal statutory rate of 21% primarily due to foreign income from the Company’s subsidiaries in Bermuda and China being taxed at lower statutory tax rates, and excess tax benefits from stock-based compensation. The decrease in the effective tax rates relative to the federal statutory rate was partially offset by the inclusion of the GILTI tax.

On December 27, 2023, the Bermuda Corporate Income Tax Act of 2023 (the “Bermuda CIT Act”) was enacted and signed into law. It includes a 15% CIT applicable to Bermuda businesses that are multinational enterprises (“MNE”) with annual revenue of €750M or more beginning in 2025. The Bermuda CIT Act also includes an Economic Transition Adjustment (“ETA”) that requires MNEs to revalue their assets and liabilities, excluding goodwill, at their fair value as of September 30, 2023. There is an election to opt out of the ETA. As the Bermuda CIT Act is not effective until January 1, 2025, the Company is evaluating whether or not to adopt this ETA. Based on the information available, the Company has not recorded any changes to income tax expense related to the Bermuda CIT Act as of June 30, 2024.

15. ACCUMULATED OTHER COMPREHENSIVE LOSS

The following table summarizes the changes in accumulated other comprehensive loss (in thousands):

	*Unrealized*
	*Losses on*			*Foreign Currency*
	*Available-for-Sale*			*Translation*
	*Securities*			*Adjustments*			*Total*
Balance as of January 1, 2024	$	(2,184	)	$	(24,878	)	$	(27,062	)
Other comprehensive income (loss) before reclassifications		87			(13,822	)		(13,735	)
Tax effect		248			-			248
Net current period other comprehensive income (loss)		335			(13,822	)		(13,487	)
Balance as of March 31, 2024		(1,849	)		(38,700	)		(40,549	)
Other comprehensive income (loss) before reclassifications		355			(4,313	)		(3,958	)
Amounts reclassified from accumulated other comprehensive loss		63			-			63
Tax effect		(50	)		-			(50	)
Net current period other comprehensive income (loss)		368			(4,313	)		(3,945	)
Balance as of June 30, 2024	$	(1,481	)	$	(43,013	)	$	(44,494	)

The amount reclassified from accumulated other comprehensive loss for the period presented was recorded in other income, net, on the Condensed Consolidated Statements of Operations.

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16. DIVIDENDS AND DIVIDEND EQUIVALENTS

Cash Dividend Program

The Company has a dividend program approved by the Board of Directors, pursuant to which the Company intends to pay quarterly cash dividends on its common stock. Based on the Company’s historical practice, stockholders of record as of the last business day of the quarter are entitled to receive the quarterly cash dividends when and if declared by the Board of Directors, which are payable to the stockholders in the following month. The Board of Directors declared the following cash dividends (in thousands, except per-share amounts):

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Dividend declared per share	$	1.25	$	1.00	$	2.50	$	2.00
Total amount	$	60,872	$	47,530	$	121,706	$	94,860

As of June 30, 2024 and December 31, 2023, accrued dividends totaled $60.9 million and $47.9 million, respectively.

The declaration of any future cash dividends is at the discretion of the Board of Directors and will depend on, among other things, the Company’s financial condition, results of operations, capital requirements, business conditions, and other factors that the Board of Directors may deem relevant, as well as a determination that cash dividends are in the best interests of the Company’s stockholders.

The Company anticipates that cash used for future dividend payments will come from its domestic cash, cash generated from ongoing U.S. operations, and cash repatriated from its Bermuda subsidiary. The Company also anticipates that earnings from other foreign subsidiaries will continue to be indefinitely reinvested.

Cash Dividend Equivalent Rights

The Company’s RSUs contain rights to receive cash dividend equivalents, which entitle employees who hold RSUs to the same dividend value per share as holders of common stock. The dividend equivalents are accumulated and paid to the employees when the underlying RSUs vest. Dividend equivalents accumulated on the underlying RSUs are forfeited if the employees do not fulfill the requisite service requirement and, as a result, the awards do not vest. As of June 30, 2024 and December 31, 2023, accrued dividend equivalents totaled $5.2 million and $11.9 million, respectively.

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Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations

This Quarterly Report on Form 10-Q contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, that have been made pursuant to and in reliance on the provisions of the Private Securities Litigation Reform Act of 1995. These statements include, among others, statements concerning:

•

the above-average industry growth of product and market areas that we have targeted;

•

our plan to increase our revenue through the introduction of new products within our existing product families as well as in new product categories and families;

•

our mission statement to reduce energy and material consumption to improve all aspects of quality of life and create a sustainable future;

•

the effects of macroeconomic factors, including the global economic downturn, the Russia-Ukraine conflict and the Middle East conflict on the semiconductor industry and our business;

•

the effect that liquidity of our investments has on our capital resources;

•

the continuing application of our products in the enterprise data, storage and computing, automotive, communications, consumer and industrial markets;

•

estimates of our future liquidity requirements;

•

the cyclical nature of the semiconductor industry;

•

our belief that we may incur significant legal expenses that vary with the level of activity in each of our current or future legal proceedings;

•

expectations regarding protection of our proprietary technology;

•

business outlook for the remainder of 2024 and beyond;

•

the factors that we believe will impact our business, operations and financial condition, as well as our ability to achieve revenue growth;

•

the expected percentage of our total revenue from various end markets;

•

our ability to identify, acquire and integrate companies, businesses and products, and achieve the anticipated benefits from such acquisitions and integrations;

•

the expected impact of various U.S. and international tax laws and regulations on our income tax provision, financial position and cash flows;

•

our plan to repatriate cash from our subsidiary in Bermuda;

•

our intention and ability to continue our stock repurchase program and pay cash dividends and dividend equivalents;

•

the factors that differentiate us from our competitors; and

•

our ability to adequately remediate our material weakness.

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In some cases, words such as “would,” “could,” “may,” “should,” “predict,” “potential,” “targets,” “continue,” “anticipate,” “expect,” “intend,” “plan,” “believe,” “seek,” “estimate,” “project,” “forecast,” “will,” the negative of these terms or other variations of such terms and similar expressions relating to the future identify forward-looking statements. All forward-looking statements are based on our current outlook, expectations, estimates, projections, beliefs and plans or objectives about our business, our industry and the global economy, including our expectations regarding the potential impacts of macroeconomic factors, such as the global economic downturn, the Russia-Ukraine conflict and the Middle East conflict on the semiconductor industry and our business. These statements are not guarantees of future performance and are subject to significant risks and uncertainties. Actual events or results could differ materially and adversely from those expressed in any such forward-looking statements. Risks and uncertainties that could cause actual results to differ materially include those set forth throughout this Quarterly Report on Form 10-Q and in our Annual Report on Form 10-K including, in particular, in the sections entitled “Risk Factors.” Except as required by law, we disclaim any duty, and undertake no obligation, to update any forward-looking statements, whether as a result of new information relating to existing conditions, future events or otherwise or to release publicly the results of any future revisions we may make to forward-looking statements to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events. Readers are cautioned not to place undue reliance on such statements, which speak only as of the date of this Quarterly Report on Form 10-Q and entail significant risks. Readers should carefully review future reports and documents that we file from time to time with the SEC, such as our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and any Current Reports on Form 8-K.

Overview

We are a fabless global company that provides high-performance, semiconductor-based power electronics solutions. MPS’s mission is to reduce energy and material consumption to improve all aspects of quality of life and create a sustainable future. Founded in 1997 by our CEO Michael Hsing, MPS has three core strengths: deep system-level knowledge, strong semiconductor design expertise, and innovative proprietary technologies in the areas of semiconductor processes, system integration, and packaging. These combined advantages are designed to enable MPS to deliver reliable, compact, and monolithic solutions that are highly energy-efficient, cost-effective, and environmentally responsible while providing a consistent return on investment to our stockholders.

We operate in the cyclical semiconductor industry. We are subject to industry downturns, but we have targeted product and market areas that we believe have the ability to offer above average industry performance over the long term. Historically, our revenue has generally been higher in the second half of the year than in the first half although various factors, such as market conditions and the timing of key product introductions, could impact this trend.

We work with third parties to manufacture and assemble our ICs. This has enabled us to limit our capital expenditures and fixed costs, while focusing our engineering and design resources on our core strengths.

Following the introduction of a product, our sales cycle generally takes a number of quarters after we receive an initial customer order for a new product to ramp up. Typical supply chain lead times for orders are generally 16 to 26 weeks. These factors, combined with the fact that our customers can cancel or reschedule orders without significant penalty to the customer, make the forecasting of our orders, revenue and expenses difficult.

We derive most of our revenue from sales through distribution arrangements and direct sales to customers in Asia, where our products are incorporated into end-user products. Our revenue from direct and indirect sales to customers in Asia was 93% and 85% of our total revenue for the three months ended June 30, 2024 and 2023, respectively, and 93% and 84% of our total revenue for the six months ended June 30, 2024 and 2023, respectively. Our revenue from indirect sales to one customer, which primarily comprised power management solutions for AI applications, was 21% and 5% of our total revenue for the three months ended June 30, 2024 and 2023, respectively, and 19% and 4% of our total revenue for the six months ended June 30, 2024 and 2023, respectively.

We derive a majority of our revenue from the sales of our DC to DC converter products which serve the enterprise data, storage and computing, automotive, communications, consumer and industrial markets. We believe our ability to achieve revenue growth will depend, in part, on our ability to develop new products, enter new market segments, gain market share, manage litigation risk, diversify our customer base and continue to secure manufacturing capacity.

Macroeconomic Conditions and Regulations

The semiconductor industry has historically been impacted by various macro-economic challenges including fluctuations in consumer spending, fluctuations in demand for semiconductors, rising inflation, increased interest rates, and fluctuations in currency rates. We remain cautious in light of continued challenging macroeconomic conditions and will continue to monitor the potential impact on our operations. The extent and duration of the direct and indirect impact of macroeconomic events on our business, results of operations and overall financial position remain uncertain and depend on future developments.

We closely monitor changes to export control laws, trade regulations and other trade requirements. To date, no restrictions have had a material impact on our revenue and operations. We will continue to monitor any changes to export control laws, trade regulations and other trade requirements and are committed to complying with all applicable trade laws, regulations and other requirements.

Critical Accounting Policies and Estimates

In preparing our condensed consolidated financial statements in accordance with GAAP, we are required to make estimates, assumptions and judgments that affect the amounts reported in our financial statements and the accompanying disclosures. Estimates and judgments used in the preparation of our condensed consolidated financial statements are, by their nature, uncertain and unpredictable, and depend upon, among other things, many factors outside of our control, including demand for our products, economic conditions and other current and future events, such as macroeconomic factors, including the impact of the global economic downturn, Russia-Ukraine conflict and the Middle East conflict. Actual results could differ from these estimates and assumptions, and any such differences may be material to our condensed consolidated financial statements.

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Results of Operations

The table below sets forth the data on the Condensed Consolidated Statements of Operations as a percentage of revenue:

	Three Months Ended June 30,								Six Months Ended June 30,
	2024				2023				2024				2023
	(In thousands, except percentages)
Revenue	$	507,431	100.0	%	$	441,128	100.0	%	$	965,316	100.0	%	$	892,193	100.0	%
Cost of revenue		226,853	44.7			193,453	43.9			432,297	44.8			385,738	43.2
Gross profit		280,578	55.3			247,675	56.1			533,019	55.2			506,455	56.8
Operating expenses:
Research and development		77,945	15.3			63,688	14.4			153,935	15.9			127,397	14.3
Selling, general and administrative		86,097	17.0			71,662	16.2			167,061	17.3			142,457	16.0
Total operating expenses		164,042	32.3			135,350	30.6			320,996	33.2			269,854	30.3
Operating income		116,536	23.0			112,325	25.5			212,023	22.0			236,601	26.5
Other income, net		7,512	1.4			6,543	1.5			17,052	1.7			11,840	1.3
Income before income taxes		124,048	24.4			118,868	27.0			229,075	23.7			248,441	27.8
Income tax expense		23,682	4.6			19,364	4.4			36,168	3.7			39,135	4.3
Net income	$	100,366	19.8	%	$	99,504	22.6	%	$	192,907	20.0	%	$	209,306	23.5	%

Revenue

The following table summarizes our revenue by end market:

	Three Months Ended June 30,										Six Months Ended June 30,
End Market	2024		% of Revenue			2023		% of Revenue			2024		% of Revenue			2023		% of Revenue
	(In thousands, except percentages)
Enterprise Data	$	187,211		36.9	%	$	47,982		10.9	%	$	336,938		34.9	%	$	95,145		10.7	%
Storage and Computing		114,955		22.7			124,543		28.2			221,076		22.9			244,365		27.4
Automotive		87,193		17.2			104,394		23.6			174,285		18.1			209,736		23.5
Communications		43,566		8.5			49,293		11.2			90,211		9.3			117,199		13.1
Consumer		42,229		8.3			65,187		14.8			80,303		8.3			128,550		14.4
Industrial		32,277		6.4			49,729		11.3			62,503		6.5			97,198		10.9
Total	$	507,431		100.0	%	$	441,128		100.0	%	$	965,316		100.0	%	$	892,193		100.0	%

Revenue for the three months ended June 30, 2024 was $507.4 million, an increase of $66.3 million, or 15.0%, from $441.1 million for the three months ended June 30, 2023. The increase in revenue was primarily due to higher average selling prices resulting primarily from product mix.

For the three months ended June 30, 2024, revenue from the enterprise data market increased $139.2 million, or 290.2%, from the same period in 2023. This increase was primarily due to higher sales of our power management solutions for AI applications. Revenue from the storage and computing market for the three months ended June 30, 2024 decreased $9.6 million, or 7.7%, from the same period in 2023. This decrease was primarily due to lower sales of storage and graphic card applications. Second quarter 2024 automotive revenue decreased $17.2 million, or 16.5%, from the same period in 2023. This decrease was primarily due to lower sales of applications supporting body electronics, digital cockpits and infotainment. Revenue from the communications market decreased $5.7 million, or 11.6%, from the same period in 2023. This decrease was primarily driven by lower demand for infrastructure related products. Second quarter 2024 revenue from the consumer market decreased $23.0 million, or 35.2%, from the same period in 2023. This decrease was primarily driven by lower sales of products for gaming and home appliances. Revenue from the industrial market decreased $17.5 million, or 35.1%, from the same period in 2023. This decrease was mainly driven by lower sales of products related to industrial meter, power source and security applications.

Revenue for the six months ended June 30, 2024 was $965.3 million, an increase of $73.1 million, or 8.2%, from $892.2 million for the six months ended June 30, 2023. The increase in revenue was primarily due to higher average selling prices resulting primarily from product mix, which was partially offset by lower shipment volume.

For the six months ended June 30, 2024, revenue from the enterprise data market increased $241.8 million, or 254.1%, from the same period in 2023. This increase was primarily due to higher sales of our power management solutions for AI applications. First half 2024 revenue from the storage and computing market decreased $23.3 million, or 9.5%, from the same period in 2023. This decrease was primarily due to lower sales of storage and graphic card applications, partially offset by higher sales of commercial notebooks. Revenue from the automotive market for the first six months of 2024 decreased $35.5 million, or 16.9%, from the same period in 2023. This decrease was primarily due to lower sales of applications supporting digital cockpits, body electronics and USB connectors. Revenue from the communications market decreased $27.0 million, or 23.0%, from the same period in 2023. This decrease was primarily driven by lower demand for infrastructure related products. For the six months ended June 30, 2024, consumer revenue decreased $48.2 million, or 37.5%, from the same period in 2023. This decrease was broad-based and primarily driven by lower sales of products for gaming and home appliances. Revenue from the industrial market decreased $34.7 million, or 35.7%, from the same period in 2023. This decrease was mainly driven by lower sales of products related to industrial meter, security and power source applications.

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Cost of Revenue and Gross Margin

Cost of revenue primarily consists of costs incurred to manufacture, assemble and test our products, as well as warranty costs, inventory-related and other overhead costs, and stock-based compensation expenses.

	Three Months Ended June 30,						Six Months Ended June 30,
	2024			2023			2024			2023
	(In thousands, except percentages)
Cost of revenue	$	226,853		$	193,453		$	432,297		$	385,738
As a percentage of revenue		44.7	%		43.9	%		44.8	%		43.2	%
Gross profit	$	280,578		$	247,675		$	533,019		$	506,455
Gross margin		55.3	%		56.1	%		55.2	%		56.8	%

Cost of revenue was $226.9 million, or 44.7% of revenue, for the three months ended June 30, 2024, and $193.5 million, or 43.9% of revenue, for the three months ended June 30, 2023. The $33.4 million increase in cost of revenue was primarily driven by increases in the average costs due to product mix.

Gross margin was 55.3% for the three months ended June 30, 2024, compared with 56.1% for the three months ended June 30, 2023. The decrease in gross margin was mainly driven by an increase in inventory write-downs and warranty expenses as a percentage of revenue, partially offset by lower manufacturing overhead costs.

Cost of revenue was $432.3 million, or 44.8% of revenue, for the six months ended June 30, 2024, and $385.7 million, or 43.2% of revenue, for the six months ended June 30, 2023. The $46.6 million increase in cost of revenue was primarily driven by increases in the average costs due to product mix, higher inventory write-downs and higher warranty expenses, partially offset by lower shipment volume.

Gross margin was 55.2% for the six months ended June 30, 2024, compared with 56.8% for the six months ended June 30, 2023. The decrease in gross margin was mainly driven by an increase in inventory write-downs and warranty expenses as a percentage of revenue, partially offset by lower manufacturing overhead costs.

Research and Development

R&D expenses primarily consist of cash compensation and benefits, stock-based compensation and deferred compensation for design and product engineers, expenses related to new product development and supplies, and facility costs.

	Three Months Ended June 30,						Six Months Ended June 30,
	2024			2023			2024			2023
	(In thousands, except percentages)
R&D expenses	$	77,945		$	63,688		$	153,935		$	127,397
As a percentage of revenue		15.3	%		14.4	%		15.9	%		14.3	%

R&D expenses were $77.9 million, or 15.3% of revenue, for the three months ended June 30, 2024, and $63.7 million, or 14.4% of revenue, for the three months ended June 30, 2023. The $14.3 million increase in R&D expenses was primarily due to a $9.0 million increase in cash compensation and benefits and a $2.4 million increase in stock-based compensation expenses.

R&D expenses were $153.9 million, or 15.9% of revenue, for the six months ended June 30, 2024, and $127.4 million, or 14.3% of revenue, for the six months ended June 30, 2023. The $26.5 million increase in R&D expenses was primarily due to a $15.3 million increase in cash compensation and benefits, a $6.0 million increase in stock-based compensation expenses and related payroll taxes and a $1.4 million increase in professional services.

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Selling, General and Administrative

SG&A expenses primarily include cash compensation and benefits, stock-based compensation and deferred compensation for sales, marketing and administrative personnel, sales commissions, travel expenses, facilities costs, third party service fees and litigation expenses.

	Three Months Ended June 30,						Six Months Ended June 30,
	2024			2023			2024			2023
	(In thousands, except percentages)
SG&A expenses	$	86,097		$	71,662		$	167,061		$	142,457
As a percentage of revenue		17.0	%		16.2	%		17.3	%		16.0	%

SG&A expenses were $86.1 million, or 17.0% of revenue, for the three months ended June 30, 2024, and $71.7 million, or 16.2% of revenue, for the three months ended June 30, 2023. The $14.4 million increase in SG&A expenses was primarily driven by an $11.5 million increase in stock-based compensation expenses and a $1.8 million increase in sales commissions.

SG&A expenses were $167.1 million, or 17.3% of revenue, for the six months ended June 30, 2024, and $142.5 million, or 16.0% of revenue, for the six months ended June 30, 2023. The $24.6 million increase in SG&A expenses was primarily driven by an $18.3 million increase in stock-based compensation expenses, a $2.0 million increase in professional services and a $1.4 million increase in cash compensation and benefits.

Other Income, Net

Other income, net, was $7.5 million for the three months ended June 30, 2024, compared with $6.5 million for the three months ended June 30, 2023. The increase in other income was primarily due to an increase in net interest income, partially offset by a decrease in income related to changes in the value of deferred compensation plan investments.

Other income, net, was $17.1 million for the six months ended June 30, 2024, compared with $11.8 million for the six months ended June 30, 2023. The increase in other income was primarily due to an increase of $12.9 million in net interest income, partially offset by an increase in charitable contributions.

Income Tax Expense

The income tax provision for interim periods is generally determined using an estimate of our annual effective tax rate and adjusted for discrete items, if any, in the relevant period. Each quarter the estimate of the annual effective tax rate is updated, and if our estimated tax rate changes, a cumulative adjustment is made.

The income tax expense for the three months ended June 30, 2024 was $23.7 million, or 19.1% of pre-tax income. The income tax expense for the six months ended June 30, 2024 was $36.2 million, or 15.8% of pre-tax income. The effective tax rates were lower than the federal statutory rate of 21% primarily due to foreign income from our subsidiaries in Bermuda and China being taxed at lower statutory tax rates, and excess tax benefits from stock-based compensation. The decrease in the effective tax rates relative to the federal statutory rate was partially offset by the inclusion of the GILTI tax.

The income tax expense for the three months ended June 30, 2023 was $19.4 million, or 16.3% of pre-tax income. The income tax expense for the six months ended June 30, 2023 was $39.1 million, or 15.8% of pre-tax income. The effective tax rates were lower than the federal statutory rate of 21% primarily due to foreign income from our subsidiaries in Bermuda and China being taxed at lower statutory tax rates, and excess tax benefits from stock-based compensation. The decrease in the effective tax rates relative to the federal statutory rate was partially offset by the inclusion of the GILTI tax.

The Organization for Economic Co-operation and Development enacted model rules for a new global minimum tax framework, also known as Pillar Two, and certain governments globally have enacted, or are in the process of enacting, legislation considering these model rules. These rules did not have a material impact on our taxes for the three and six months ended June 30, 2024.

In December 2023, the Bermuda CIT Act was enacted and signed into law. See Note 14 for further details.

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Liquidity and Capital Resources

	June 30,			December 31,
	2024			2023
	(In thousands, except percentages)
Cash and cash equivalents	$	550,475		$	527,843
Short-term investments		756,770			580,633
Total cash, cash equivalents and short-term investments	$	1,307,245		$	1,108,476
Percentage of total assets		49.4	%		45.5	%

Total current assets	$	1,997,433		$	1,819,499
Total current liabilities		(295,159	)		(235,035	)
Working capital	$	1,702,274		$	1,584,464

As of June 30, 2024, we had cash and cash equivalents of $550.5 million and short-term investments of $756.8 million, compared with cash and cash equivalents of $527.8 million and short-term investments of $580.6 million as of December 31, 2023. As of June 30, 2024, $335.3 million of cash and cash equivalents and $715.1 million of short-term investments were held by our international subsidiaries. We have repatriated and may continue to repatriate cash from our Bermuda subsidiary to fund our expenditures in future periods. We anticipate that earnings from other foreign subsidiaries will continue to be indefinitely reinvested.

Summary of Cash Flows

The following table summarizes our cash flow activities:

	Six Months Ended June 30,
	2024			2023
	(In thousands)
Net cash provided by operating activities	$	389,026		$	308,992
Net cash provided by (used in) investing activities		(269,366	)		263
Net cash used in financing activities		(123,638	)		(82,204	)
Effect of change in exchange rates		(6,603	)		(8,696	)
Net increase (decrease) in cash, cash equivalents and restricted cash	$	(10,581	)	$	218,355

For the six months ended June 30, 2024, the $80.0 million increase in cash provided by operating activities compared to the same period in 2023 was primarily due to increased accounts receivable collections and the collection of $50.0 million of other receivables related to a long-term wafer supply agreement, partially offset by increased inventory purchases. This increase was also affected by changes in other working capital.

For the six months ended June 30, 2024, the $269.6 million increase in cash used in investing activities compared to the same period in 2023 was primarily due to an increase of $378.2 million in purchases of investments, partially offset by an increase of $188.3 million in sales of investments.

For the six months ended June 30, 2024, the $41.4 million increase in cash used in financing activities compared to the same period in 2023 was primarily due to an increase of $31.7 million in dividend and dividend equivalent payments.

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Cash Requirements

Although consequences of economic uncertainty and macroeconomic conditions and other factors could adversely affect our liquidity and capital resources in the future, and our cash requirements may fluctuate based on the timing and extent of many factors such as those discussed above, we believe that our balances of cash, cash equivalents and short-term investments of $1,307.2 million as of June 30, 2024, along with cash generated by ongoing operations, will be sufficient to satisfy our liquidity requirements for the next 12 months and beyond.

Our material cash requirements include the following contractual and other obligations:

Purchase Obligations

Purchase obligations represent commitments to our suppliers and other parties requiring the purchases of goods or services. Our purchase obligations primarily consist of wafer and other inventory purchases, assembly and other manufacturing services, construction of manufacturing and R&D facilities, purchases of production and other equipment, and license arrangements.

In May 2022, we entered into a long-term supply agreement in order to secure manufacturing production capacity for silicon wafers over a four-year period. As of June 30, 2024, we had remaining prepayments under this agreement of $120.0 million, of which $60.0 million was classified as short-term.

As of June 30, 2024, total estimated future unconditional purchase commitments to all suppliers and other parties, net of the $120.0 million prepayment, were $571.6 million, of which $394.1 million was classified as short-term.

Transition Tax Liability

The transition tax liability represents the one-time, mandatory deemed repatriation tax imposed on previously deferred foreign earnings under the U.S. Tax Cuts and Jobs Act enacted in December 2017 (the “2017 Tax Act”). As permitted by the 2017 Tax Act, we have elected to pay the tax liability in installments on an interest-free basis through 2025. As of June 30, 2024, the remaining liability totaled $6.2 million, all of which was classified as short-term.

Operating Leases

Operating lease obligations represent the undiscounted remaining lease payments primarily for our leased facilities and equipment. As of June 30, 2024, these obligations totaled $15.5 million, of which $2.4 million was classified as short-term.

Capital Return to Stockholders

In October 2023, our Board of Directors approved a new stock repurchase program authorizing us to repurchase up to $640.0 million in the aggregate of our common stock through October 29, 2026. Shares are retired upon repurchase. We repurchased 6,300 and 12,400 shares of our common stock for an aggregate purchase price of $4.5 million and $8.6 million during the three and six months ended June 30, 2024, respectively. As of June 30, 2024, $627.6 million remained available for future repurchases under the program.

We currently have a dividend program approved by our Board of Directors, pursuant to which we intend to pay quarterly cash dividends on our common stock. Based on our historical practice, stockholders of record as of the last business day of the quarter are entitled to receive the quarterly cash dividends when and if declared by the Board of Directors, which are payable to the stockholders in the following month. As of June 30, 2024, accrued dividends totaled $60.9 million. The declaration of any future cash dividends is at the discretion of our Board of Directors and will depend on, among other things, our financial condition, results of operations, capital requirements, business conditions and other factors that our Board of Directors may deem relevant, as well as a determination that cash dividends are in the best interests of our stockholders.

Other Long-Term Obligations

Other long-term obligations primarily include payments for deferred compensation plan liabilities and accrued dividend equivalents. As of June 30, 2024, these obligations totaled $83.6 million.

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Item 3. Quantitative and Qualitative Disclosures About Market Risk

For a discussion of market risks, refer to Item 7A, “Quantitative and Qualitative Disclosures about Market Risk” in our Annual Report on Form 10-K for the year ended December 31, 2023. During the three and six months ended June 30, 2024, there were no material changes or developments that would have materially altered, or were reasonably likely to materially alter, the market risk assessment performed as of December 31, 2023.

Item 4. Controls and Procedures

Evaluation of Disclosure Controls and Procedures

Our management, with the participation of our Chief Executive Officer and Chief Financial Officer, evaluated the effectiveness of our disclosure controls and procedures pursuant to Rule 13a-15(e) and Rule 15d-15(e) under the Securities Exchange Act of 1934 as of the end of the period covered by this Quarterly Report on Form 10-Q.

Based on this evaluation, and due to the finding of the material weakness described below, our Chief Executive Officer and Chief Financial Officer concluded that, as of June 30, 2024, our disclosure controls and procedures were not effective to provide reasonable assurance that information we are required to disclose in reports that we file or submit under the Exchange Act is recorded, processed, summarized, and reported within the time periods specified in the SEC’s rules and forms.

As previously reported in our Annual Report on Form 10-K for the year ended December 31, 2023, during the year-end financial reporting process of fiscal year 2023, a material weakness was identified in internal control over financial reporting within the Company’s demand forecast process regarding excess and obsolete inventory. The material weakness resulted from ineffective design of the controls related to management’s review and documentation of the Company’s inventory demand information and other assumptions used to determine the inventory carrying value adjustments necessary to record such quantities at the lower of their cost or net realizable value.

A material weakness is a deficiency, or a combination of deficiencies in internal control over financial reporting, such that there is a reasonable possibility that a material misstatement of the Company’s annual or interim consolidated financial statements will not be prevented or detected on a timely basis. This material weakness did not result in a misstatement to the audited consolidated financial statements for the year ended December 31, 2023.

Notwithstanding the material weakness in internal control over financial reporting described above, management believes and has concluded that the condensed consolidated financial statements included in this Quarterly Report on Form 10-Q fairly present, in all material respects, our financial position, results of operations and cash flows for the periods presented in conformity with GAAP.

Ongoing Remediation of Previously Identified Material Weakness

With respect to the material weakness described above, management, under the oversight of the Audit Committee, has implemented measures designed to ensure that control deficiencies contributing to the material weakness are remediated, such that these controls are designed, implemented, and operating effectively. However, the weakness will not be considered remediated until the applicable controls operate for a sufficient period of time and management has concluded, through testing, that these controls are operating effectively. The Company will monitor the effectiveness of its remediation plan and refine its remediation plan as appropriate.

Changes in Internal Control over Financial Reporting

As described above, we are taking steps to remediate the material weakness in our internal control over financial reporting. Other than in connection with the remediation process described above, no change in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) occurred during the quarter ended June 30, 2024 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

Limitations on Effectiveness of Controls and Procedures

In designing and evaluating the disclosure controls and procedures, management recognizes that any set of controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives. In addition, the design of disclosure controls and procedures must reflect the fact that there are resource constraints, and that management is required to apply its judgment in evaluating the benefits of possible controls and procedures relative to their costs.

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PART II. OTHER INFORMATION

Item 1. Legal Proceedings

We are a party to actions and proceedings in the ordinary course of business, including challenges to the enforceability or validity of our intellectual property, claims that our products infringe on the intellectual property rights of others, and employment matters. We may also be subject to litigation initiated by our stockholders. These proceedings often involve complex questions of fact and law and may require the expenditure of significant funds and the diversion of other resources to prosecute and defend. We defend ourselves vigorously against any such claims. As of June 30, 2024, there were no material pending legal proceedings to which we were a party.

Item 1A. Risk Factors

The Company’s business, reputation, results of operations, financial condition and stock price can be affected by a number of factors, whether currently known or unknown, including those described in Part I, Item 1A of the Annual Report on Form 10-K for the year ended December 31, 2023 under the heading “Risk Factors.” When any one or more of these risks materialize from time to time, the Company’s business, reputation, results of operations, financial condition and stock price can be materially and adversely affected. There have been no material changes to the Company’s risk factors since the filing of the Annual Report on Form 10-K for the year ended December 31, 2023.

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Item 2. Unregistered Sales of Equity Securities and Use of Proceeds

Issuer Purchases of Equity Securities

In October 2023, our Board of Directors approved a stock repurchase program authorizing us to repurchase up to $640.0 million in the aggregate of our common stock through October 29, 2026. Shares are retired upon repurchase. We repurchased 6,300 and 12,400 shares of our common stock for an aggregate purchase price of $4.5 million and $8.6 million during the three and six months ended June 30, 2024, respectively.

Stock repurchases under the program may be made through open market repurchases, privately negotiated transactions or other structures in accordance with applicable state and federal securities laws, at times and in amounts as management deems appropriate. The timing and the number of shares of any repurchased common stock will be determined by our management based on the evaluation of market conditions, legal requirements, stock price, and other factors. The repurchase program does not obligate us to purchase any particular number of shares and may be suspended, modified, or discontinued at any time without prior notice.

The following table represents details of our stock repurchase transactions during the three months ended June 30, 2024:

Period	Total Number of Shares Purchased		Average Price Paid per Share		Total Number of Shares Purchased as Part of Publicly Announced Program		Approximate Dollar Value of Shares that May Yet Be Purchased Under the Program
	(In thousands, except per share amounts)
April 1, 2024 – April 30, 2024		2	$	655.61		2	$	630,741
May 1, 2024 – May 31, 2024		2	$	727.63		2	$	629,140
June 1, 2024 – June 30, 2024		2	$	792.89		2	$	627,633
Total		6	$	722.16		6

Item 3. Defaults Upon Senior Securities

None.

Item 4. Mine Safety Disclosures

Not applicable.

Item 5. Other Information

Certain of our executive officers have entered into trading plans pursuant to Rule 10b5-1(c) of the Securities Exchange Act of 1934, as amended. A trading plan is a written document that pre-establishes the amounts, prices and dates (or formula for determining the amounts, prices and dates) of future purchases or sales of our common stock, including the exercise and sale of shares acquired pursuant to the 2004 ESPP, and upon vesting of RSUs.

During the three months ended June 30, 2024, no trading plans intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) were adopted, modified, or terminated, and no other written trading arrangements that are not intended to qualify for the Rule 10b5-1(c) affirmative defense were adopted, modified, or terminated.

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Item 6. Exhibits

Exhibit No.	Description
31.1	Certification of Chief Executive Officer pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a), as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
31.2	Certification of Chief Financial Officer pursuant to Securities Exchange Act Rules 13a-14(a) and 15d-14(a), as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
32.1*	Certification of Chief Executive Officer and Chief Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
101.INS	Inline XBRL Instance Document - the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document
101.SCH	Inline XBRL Taxonomy Extension Schema Document
101.CAL	Inline XBRL Taxonomy Extension Calculation Linkbase Document
101.DEF	Inline XBRL Taxonomy Extension Definition Linkbase Document
101.LAB	Inline XBRL Taxonomy Extension Label Linkbase Document
101.PRE	Inline XBRL Taxonomy Extension Presentation Linkbase Document
104	Cover Page Interactive Data File (formatted as Inline XBRL and contained in Exhibit 101)

This exhibit shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934 or otherwise subject to the liabilities of that Section, nor shall it be deemed incorporated by reference in any filings under the Securities Act of 1933 or the Securities Exchange Act of 1934, whether made before or after the date hereof and irrespective of any general incorporation language in any filings.

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MONOLITHIC POWER SYSTEMS, INC

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

	MONOLITHIC POWER SYSTEMS, INC.

Dated: August 2, 2024
	By:	/s/ T. Bernie Blegen
		T. Bernie Blegen
		Executive Vice President and Chief Financial Officer
		(Duly Authorized Officer and Principal
		Financial and Accounting Officer)

Exhibit 31.1

CERTIFICATION OF CHIEF EXECUTIVE OFFICER PURSUANT TO

SECURITIES EXCHANGE ACT RULES 13a-14(a) and 15d-14(a), AS ADOPTED PURSUANT TO

SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Michael Hsing, certify that:

1. I have reviewed this Quarterly Report on Form 10-Q of Monolithic Power Systems, Inc.;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

(d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: August 2, 2024

	/s/ Michael Hsing
	Michael Hsing
	Chief Executive Officer

Exhibit 31.2

CERTIFICATION OF CHIEF FINANCIAL OFFICER PURSUANT TO

SECURITIES EXCHANGE ACT RULES 13a-14(a) and 15d-14(a), AS ADOPTED PURSUANT TO

SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, T. Bernie Blegen, certify that:

1. I have reviewed this Quarterly Report on Form 10-Q of Monolithic Power Systems, Inc.;

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: August 2, 2024

	/s/ T. Bernie Blegen
	T. Bernie Blegen
	Executive Vice President and Chief Financial Officer

Exhibit 32.1

The following certification shall not be deemed “filed” for purposes of section 18 of the Securities Exchange Act of 1934 or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933 or the Securities Exchange Act of 1934, whether made before or after the date hereof and irrespective of any general incorporation language in any filings.

CERTIFICATION OF CHIEF EXECUTIVE OFFICER AND

CHIEF FINANCIAL OFFICER PURSUANT TO

18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report on Form 10-Q of Monolithic Power Systems, Inc., a Delaware corporation, for the quarter ended June 30, 2024 (the “Report”), as filed with the Securities and Exchange Commission, each of the undersigned officers of Monolithic Power Systems, Inc. certifies pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) the accompanying Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

(2) the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Monolithic Power Systems, Inc. for the periods presented therein.

Date: August 2, 2024

	/s/ Michael Hsing
	Michael Hsing
	Chief Executive Officer

Date: August 2, 2024

	/s/ T. Bernie Blegen
	T. Bernie Blegen
	Executive Vice President and Chief Financial Officer

Document And Entity Information - shares	6 Months Ended
Document And Entity Information - shares	Jun. 30, 2024	Jul. 26, 2024
Document Information [Line Items]
Entity Central Index Key	0001280452
Entity Registrant Name	MONOLITHIC POWER SYSTEMS INC
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2024
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2024
Document Transition Report	false
Entity File Number	000-51026
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	77-0466789
Entity Address, Address Line One	5808 Lake Washington Blvd. NE
Entity Address, City or Town	Kirkland
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98033
City Area Code	425
Local Phone Number	296-9956
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	MPWR
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		48,752,000

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 550,475	$ 527,843
Short-term investments	756,770	580,633
Accounts receivable, net	157,890	179,858
Inventories	426,751	383,702
Other current assets	105,547	147,463
Total current assets	1,997,433	1,819,499
Property and equipment, net	400,534	368,952
Acquisition-related intangible assets, net	10,512	0
Goodwill	26,080	6,571
Deferred tax assets, net	29,707	28,054
Other Assets, Noncurrent	183,866	211,277
Total assets	2,648,132	2,434,353
Liabilities, Current [Abstract]
Accounts payable	99,894	62,958
Accrued compensation and related benefits	63,917	56,286
Other accrued liabilities	131,348	115,791
Total current liabilities	295,159	235,035
Income tax liabilities	60,440	60,724
Other long-term liabilities	96,675	88,655
Total liabilities	452,274	384,414
Commitments and contingencies
Stockholders’ equity:
Common stock and additional paid-in capital: $0.001 par value; shares authorized: 150,000; shares issued and outstanding: 48,698 and 48,028, respectively	1,224,144	1,129,937
Retained earnings	1,016,208	947,064
Accumulated other comprehensive loss	(44,494)	(27,062)
Total stockholders’ equity	2,195,858	2,049,939
Total liabilities and stockholders’ equity	$ 2,648,132	$ 2,434,353

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares shares in Thousands	Jun. 30, 2024	Dec. 31, 2023
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	150,000	150,000
Common stock, shares issued (in shares)	48,698	48,028
Common stock, shares outstanding (in shares)	48,698	48,028

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenue	$ 507,431	$ 441,128	$ 965,316	$ 892,193
Cost of revenue	226,853	193,453	432,297	385,738
Gross profit	280,578	247,675	533,019	506,455
Operating expenses:
Research and development	77,945	63,688	153,935	127,397
Selling, general and administrative	86,097	71,662	167,061	142,457
Total operating expenses	164,042	135,350	320,996	269,854
Operating income	116,536	112,325	212,023	236,601
Other income, net	7,512	6,543	17,052	11,840
Income before income taxes	124,048	118,868	229,075	248,441
Income tax expense	23,682	19,364	36,168	39,135
Net income	$ 100,366	$ 99,504	$ 192,907	$ 209,306
Net income per share
Basic (in dollars per share)	$ 2.06	$ 2.1	$ 3.96	$ 4.42
Diluted (in dollars per share)	$ 2.05	$ 2.04	$ 3.94	$ 4.3
Weighted-average shares outstanding:
Basic (in shares)	48,687	47,489	48,660	47,361
Diluted (in shares)	48,945	48,756	48,935	48,705

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Net income	$ 100,366	$ 99,504	$ 192,907	$ 209,306
Other comprehensive loss, net of tax:
Foreign currency translation adjustments	(4,313)	(26,180)	(18,135)	(23,261)
Change in unrealized gains and losses on available-for-sale securities, net of tax of $50, $158, $(198) and $469, respectively	368	728	703	2,941
Other comprehensive loss, net of tax:	(3,945)	(25,452)	(17,432)	(20,320)
Comprehensive income	$ 96,421	$ 74,052	$ 175,475	$ 188,986

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (Parentheticals) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Change in unrealized gain (loss) on available-for-sale securities, tax	$ 50	$ 158	$ (198)	$ 469

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock Including Additional Paid in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Dec. 31, 2022	47,107,000
Balance at Dec. 31, 2022	$ 975,276	$ 716,403	$ (23,077)	$ 1,668,602
Net income	0	209,306	0	209,306
Other comprehensive loss	0	0	(20,320)	(20,320)
Dividends and dividend equivalents declared	$ 0	(98,353)	0	(98,353)
Common stock issued under the employee equity incentive plan (in shares)	495,000
Common stock issued under the employee equity incentive plan	$ 1,114	0	0	1,114
Stock-based compensation expense	75,003	0	0	75,003
Other comprehensive loss	$ 0	0	(20,320)	(20,320)
Common stock issued under the employee stock purchase plan (in shares)	9,000
Common stock issued under the employee stock purchase plan	$ 3,737	0	0	3,737
Balance (in shares) at Jun. 30, 2023	47,611,000
Balance at Jun. 30, 2023	$ 1,055,130	827,356	(43,397)	1,839,089
Balance (in shares) at Mar. 31, 2023	47,411,000
Balance at Mar. 31, 2023	$ 1,017,131	777,075	(17,945)	1,776,261
Net income	0	99,504	0	99,504
Other comprehensive loss	0	0	(25,452)	(25,452)
Dividends and dividend equivalents declared	$ 0	(49,223)	0	(49,223)
Common stock issued under the employee equity incentive plan (in shares)	200,000
Common stock issued under the employee equity incentive plan	$ 4	0	0	4
Stock-based compensation expense	37,995	0	0	37,995
Other comprehensive loss	$ 0	0	(25,452)	(25,452)
Balance (in shares) at Jun. 30, 2023	47,611,000
Balance at Jun. 30, 2023	$ 1,055,130	827,356	(43,397)	$ 1,839,089
Balance (in shares) at Dec. 31, 2023	48,028,000			48,028,000
Balance at Dec. 31, 2023	$ 1,129,937	947,064	(27,062)	$ 2,049,939
Net income	0	192,907	0	192,907
Other comprehensive loss	0	0	(17,432)	(17,432)
Dividends and dividend equivalents declared	$ 0	(123,763)	0	(123,763)
Common stock issued under the employee equity incentive plan (in shares)	671,000
Common stock issued under the employee equity incentive plan	$ 0	0	0	$ 0
Repurchases of common stock (in shares)	(12,000)			(12,400)
Repurchases of common stock	$ (8,626)	0	0	$ (8,626)
Stock-based compensation expense	98,227	0	0	98,227
Other comprehensive loss	$ 0	0	(17,432)	(17,432)
Common stock issued under the employee stock purchase plan (in shares)	11,000
Common stock issued under the employee stock purchase plan	$ 4,606	0	0	$ 4,606
Balance (in shares) at Jun. 30, 2024	48,698,000			48,698,000
Balance at Jun. 30, 2024	$ 1,224,144	1,016,208	(44,494)	$ 2,195,858
Balance (in shares) at Mar. 31, 2024	48,667,000
Balance at Mar. 31, 2024	$ 1,176,382	977,724	(40,549)	2,113,557
Net income	0	100,366	0	100,366
Other comprehensive loss	0	0	(3,945)	(3,945)
Dividends and dividend equivalents declared	$ 0	(61,882)	0	(61,882)
Common stock issued under the employee equity incentive plan (in shares)	37,000
Common stock issued under the employee equity incentive plan	$ 0	0	0	$ 0
Repurchases of common stock (in shares)	(6,000)			(6,300)
Repurchases of common stock	$ (4,550)	0	0	$ (4,550)
Stock-based compensation expense	52,312	0	0	52,312
Other comprehensive loss	$ 0	0	(3,945)	$ (3,945)
Balance (in shares) at Jun. 30, 2024	48,698,000			48,698,000
Balance at Jun. 30, 2024	$ 1,224,144	$ 1,016,208	$ (44,494)	$ 2,195,858

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parentheticals) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Dividends and dividend equivalents declared per share (in dollars per share)	$ 1.25	$ 1	$ 2.5	$ 2

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Cash flows from operating activities:
Net income	$ 192,907	$ 209,306
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	16,942	19,940
Amortization of premium (discount) on available-for-sale securities	(10,040)	56
Gain on deferred compensation plan investments	(5,285)	(5,022)
Gain on sale of equity investments	0	(1,424)
Deferred taxes, net	(5,821)	(984)
Stock-based compensation expense	98,232	75,001
Other	77	0
Changes in operating assets and liabilities:
Accounts receivable	21,951	13,544
Inventories	(42,350)	19,847
Other assets	60,590	(4,881)
Accounts payable	30,725	12,653
Accrued compensation and related benefits	8,353	(20,613)
Income tax liabilities	7,459	(14,802)
Other accrued liabilities	15,286	6,371
Net cash provided by operating activities	389,026	308,992
Cash flows from investing activities:
Purchases of property and equipment	(47,498)	(16,681)
Cash paid for an assumed lease	(18,175)	0
Purchases of investments	(589,615)	(211,407)
Maturities and sales of investments	420,514	232,206
Cash paid for acquisition, net of cash acquired	(33,283)	0
Contributions to deferred compensation plan, net	(1,309)	(3,855)
Net cash provided by (used in) investing activities	(269,366)	263
Cash flows from financing activities:
Property and equipment purchased on extended payment terms	(2,010)	(1,192)
Proceeds from common stock issued under the employee equity incentive plan	0	1,114
Proceeds from common stock issued under the employee stock purchase plan	4,606	3,737
Repurchases of common stock	(8,626)	0
Dividends and dividend equivalents paid	(117,608)	(85,863)
Net cash used in financing activities	(123,638)	(82,204)
Effect of change in exchange rates	(6,603)	(8,696)
Net increase (decrease) in cash, cash equivalents and restricted cash	(10,581)	218,355
Cash, cash equivalents and restricted cash, beginning of period	561,181	288,729
Cash, cash equivalents and restricted cash, end of period	550,600	507,084
Supplemental disclosures for cash flow information:
Cash paid for income taxes, net	34,064	58,216
Non-cash investing and financing activities:
Liability accrued for property and equipment purchases	7,488	2,586
Liability accrued for dividends and dividend equivalents	$ 62,949	$ 51,037

Note 1 - Basis of Presentation

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Significant Accounting Policies [Text Block]

1. BASIS OF PRESENTATION

Use of Estimates

New Accounting Pronouncements Not Yet Adopted as of June 30, 2024

Note 2 - Revenue Recognition

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Revenue from Contract with Customer [Text Block]

2. REVENUE RECOGNITION

Revenue from Product Sales

Variable Consideration

Contract Balances

Accounts Receivable:

Contract Liabilities:

Practical Expedients

The Company has elected the practical expedient to expense sales commissions as incurred because the amortization period would have been one year or less.

Note 3 - Stock-based Compensation

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Share-Based Payment Arrangement [Text Block]

3. STOCK-BASED COMPENSATION

2014 Equity Incentive Plan

Stock-Based Compensation Expense

The Company recognized stock-based compensation expenses as follows (in thousands):

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Cost of revenue	$	1,611	$	1,150	$	3,009	$	2,297
Research and development		11,682		9,313		22,129		17,927
Selling, general and administrative (“SG&A”)		39,013		27,529		73,094		54,777
Total stock-based compensation expense	$	52,306	$	37,992	$	98,232	$	75,001
Tax benefit related to stock-based compensation ⁽¹⁾	$	798	$	663	$	1,506	$	1,086

(1)

Restricted Stock Units (“RSUs”)

A summary of RSU activity is presented in the table below (in thousands, except per-share amounts):

	*Time-Based RSUs*					*PSUs and MPSUs*						*MSUs*					*Total*
				*Weighted-*						*Weighted-*					*Weighted-*					*Weighted-*
				*Average*						*Average*					*Average*					*Average*
				*Grant Date*						*Grant Date*					*Grant Date*					*Grant Date*
	*Number of*			*Fair Value*		*Number of*				*Fair Value*		*Number of*			*Fair Value*		*Number of*			*Fair Value*
	*Shares*			*Per Share*		*Shares*				*Per Share*		*Shares*			*Per Share*		*Shares*			*Per Share*
Outstanding at January 1, 2024		102		$	411.11		482			$	397.77		1,502		$	152.89		2,086		$	222.04
Granted		30		$	635.67		344		⁽¹⁾	$	593.33		-		$	-		374		$	596.68
Vested		(31	)	$	363.82		(77	)		$	307.93		(563	)	$	68.48		(671	)	$	109.62
Forfeited		(3	)	$	465.22		(1	)		$	396.40		(1	)	$	270.15		(5	)	$	412.40
Outstanding at June 30, 2024		98		$	493.16		748			$	496.84		938		$	203.33		1,784		$	342.19

(1)	Amount reflects the number of awards that may ultimately be earned based on management’s probability assessment of the achievement of performance conditions at each reporting period.

Time-Based RSUs:

2024 PSUs:

2004 Employee Stock Purchase Plan (as amended and restated, the “2004 ESPP”)

	*Six Months Ended June 30,*
	*2024*			*2023*
Expected term (in years)		0.5			0.5
Expected volatility		42.4	%		55.8	%
Risk-free interest rate		5.3	%		5.0	%
Dividend yield		0.7	%		0.8	%

Cash proceeds from the shares issued under the 2004 ESPP were $4.6 million and $3.7 million for the six months ended June 30, 2024 and 2023, respectively.

Note 4 - Acquisition

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Business Combination Disclosure [Text Block]

4. ACQUISITION

Purchase Consideration

Purchase Price Allocation

The purchase price allocation for Axign is as follows (in thousands):

Inventory	$	720
Other tangible assets acquired, net of liabilities assumed		1,487
Intangible assets:
Developed technology		9,184
IPR&D		2,147
Total identifiable net assets acquired		13,538
Goodwill		19,860
Total net assets acquired	$	33,398

Note 5 - Balance Sheet Components

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Supplemental Balance Sheet Disclosures [Text Block]

5. BALANCE SHEET COMPONENTS

Inventories

Inventories consist of the following (in thousands):

	*June 30,*		*December 31,*
	*2024*		*2023*
Raw materials	$	93,435	$	118,917
Work in process		164,116		112,750
Finished goods		169,200		152,035
Total	$	426,751	$	383,702

Other Current Assets

Other current assets consist of the following (in thousands):

	*June 30,*		*December 31,*
	*2024*		*2023*
Prepaid wafer purchases	$	60,000	$	-
Prepaid expenses		27,570		28,964
RSU tax withholding proceeds receivable		71		20,141
Other receivables		-		50,000
Restricted cash		-		33,204
Other		17,906		15,154
Total	$	105,547	$	147,463

Other Long-Term Assets

Other long-term assets consist of the following (in thousands):

	*June 30,*		*December 31,*
	*2024*		*2023*
Deferred compensation plan assets	$	84,975	$	78,381
Prepaid wafer purchases		60,000		120,000
Operating lease right-of-use (“ROU”) and related assets		33,681		8,355
Other		5,210		4,541
Total	$	183,866	$	211,277

Other Accrued Liabilities

Other accrued liabilities consist of the following (in thousands):

	*June 30,*		*December 31,*
	*2024*		*2023*
Dividends and dividend equivalents	$	62,524	$	57,697
Stock rotation and sales returns		21,716		18,843
Warranty		14,702		16,906
Customer prepayments		5,564		2,792
Accrued legal expenses		4,249		1,277
Income tax payable		9,641		8,063
Other		12,952		10,213
Total	$	131,348	$	115,791

Other Long-Term Liabilities

Other long-term liabilities consist of the following (in thousands):

	*June 30,*		*December 31,*
	*2024*		*2023*
Deferred compensation plan liabilities	$	80,115	$	80,903
Operating lease liabilities		13,045		5,565
Dividend equivalents		3,515		2,187
Total	$	96,675	$	88,655

Note 6 - Leases

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Leases Disclosure [Text Block]

6. LEASES

Lessee

The following table summarizes the balances of operating lease ROU assets and liabilities (in thousands):

		*June 30,*		*December 31,*
	*Financial Statement Line Item*	*2024*		*2023*
Operating lease ROU assets	Other long-term assets	$	15,956	$	8,355

Operating lease liabilities	Other accrued liabilities	$	2,446	$	2,303
	Other long-term liabilities	$	13,045	$	5,565

The following tables summarize certain information related to the leases (in thousands, except percentages and years):

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Lease costs:
Operating lease costs	$	1,014	$	759	$	1,911	$	1,475
Other		648		554		1,198		1,092
Total lease costs	$	1,662	$	1,313	$	3,109	$	2,567

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows for operating leases	$	1,027	$	774	$	1,700	$	1,638
ROU assets obtained in exchange for new operating lease liabilities	$	7,809	$	290	$	9,271	$	4,835

	*June 30,*			*December 31,*
	*2024*			*2023*
Weighted-average remaining lease term (in years)		12.1			4.7
Weighted-average discount rate		5.4	%		4.3	%

As of June 30, 2024, the maturities of the lease liabilities were as follows (in thousands):

2024 (remaining six months)	$	1,617
2025		2,997
2026		2,249
2027		2,012
2028		1,380
Thereafter		12,534
Total remaining lease payments		22,789
Less: imputed interest		(7,298	)
Total lease liabilities	$	15,491

As of June 30, 2024, operating leases that have not yet commenced are not material.

Lessor

2024 (remaining six months)	$	525
2025		578
2026		402
2027		373
2028		384
Thereafter		129
Total	$	2,391

Note 7 - Net Income Per Share

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Earnings Per Share [Text Block]

7. NET INCOME PER SHARE

The following table sets forth the computation of basic and diluted net income per share (in thousands, except per-share amounts):

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Numerator:
Net income	$	100,366	$	99,504	$	192,907	$	209,306

Denominator:
Weighted-average outstanding shares — basic		48,687		47,489		48,660		47,361
Effect of dilutive securities		258		1,267		275		1,344
Weighted-average outstanding shares — diluted		48,945		48,756		48,935		48,705

Net income per share:
Basic	$	2.06	$	2.10	$	3.96	$	4.42
Diluted	$	2.05	$	2.04	$	3.94	$	4.30

Anti-dilutive common stock equivalents were not material in any of the periods presented.

Note 8 - Segment, Significant Customers and Geographic Information

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Segment Reporting Disclosure [Text Block]

8. SEGMENT, SIGNIFICANT CUSTOMERS AND GEOGRAPHIC INFORMATION

	Three Months Ended June 30,						Six Months Ended June 30,
Customer	2024			2023			2024			2023
Distributor A		38	%		22	%		40	%		21	%
Distributor B		17	%		20	%		15	%		21	%
Distributor C		*			11	%		*			10	%

The following table summarizes those customers with accounts receivable equal to 10% or more of the Company’s total accounts receivable:

	*June 30,*			*December 31,*
Customer	*2024*			*2023*
Distributor A		41	%		42	%
Distributor B		24	%		13	%
Distributor C		*			10	%

* Represents less than 10%

The following is a summary of revenue by geographic region (in thousands):

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
Country or Region	*2024*		*2023*		*2024*		*2023*
China	$	282,514	$	216,172	$	545,554	$	441,224
Taiwan		127,396		70,212		227,846		119,045
South Korea		39,513		40,669		75,050		86,349
Europe		19,105		36,348		36,847		79,451
United States		13,927		27,571		28,747		58,588
Southeast Asia		11,352		21,708		24,591		48,140
Japan		13,552		28,288		26,500		59,103
Other		72		160		181		293
Total	$	507,431	$	441,128	$	965,316	$	892,193

In the second quarter of 2024, the Company reclassified certain products in its product families. The prior periods in the table below have been updated to conform with the new methodology.

The following is a summary of revenue by product family (in thousands):

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
Product Family	*2024*		*2023*		*2024*		*2023*
Direct Current (“DC”) to DC	$	501,302	$	418,175	$	947,367	$	843,356
Lighting Control		6,129		22,953		17,949		48,837
Total	$	507,431	$	441,128	$	965,316	$	892,193

The following is a summary of long-lived assets by geographic region (in thousands):

	*June 30,*		*December 31,*
Country	*2024*		*2023*
China	$	207,614	$	184,685
United States		124,000		119,430
Taiwan		37,071		39,419
Other		31,849		25,418
Total	$	400,534	$	368,952

Note 9 - Commitments and Contingencies

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Commitments and Contingencies Disclosure [Text Block]

9. COMMITMENTS AND CONTINGENCIES

Product Warranties

The changes in warranty reserves are as follows (in thousands):

	*Three Months Ended June 30,*						*Six Months Ended June 30,*
	*2024*			*2023*			*2024*			*2023*
Balance at beginning of period	$	12,873		$	19,726		$	16,906		$	24,082
Warranties issued		2,225			580			2,325			942
Repairs, replacement and refund		(116	)		(1,581	)		(4,130	)		(2,253	)
Changes in liability for pre-existing warranties		(280	)		(1,071	)		(399	)		(5,117	)
Balance at end of period	$	14,702		$	17,654		$	14,702		$	17,654

Changes in liability for pre-existing warranties result from changes in estimates for warranties issued in prior periods.

Purchase Commitments

Total estimated future unconditional purchase commitments to all suppliers and other parties, net of the $120.0 million prepayment, as of June 30, 2024 were as follows (in thousands):

2024 (remaining six months)	$	151,590
2025		388,949
2026		1,572
2027		29,476
Total	$	571,587

Litigation

Note 10 - Cash, Cash Equivalents, Investments and Restricted Cash

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Financial Instruments Disclosure [Text Block]

10. CASH, CASH EQUIVALENTS, INVESTMENTS AND RESTRICTED CASH

The following is a summary of the Company’s cash, cash equivalents and debt investments (in thousands):

	*June 30,*		*December 31,*
	*2024*		*2023*
Cash	$	357,743	$	392,329
Money market funds		192,732		135,514
Certificates of deposit		165,120		127,123
Corporate debt securities		22,729		95,101
U.S. treasuries and government agency bonds		568,921		358,409
Auction-rate securities backed by student-loan notes		345		567
Total	$	1,307,590	$	1,109,043

	*June 30,*		*December 31,*
	*2024*		*2023*
Reported as:
Cash and cash equivalents	$	550,475	$	527,843
Short-term investments		756,770		580,633
Investment within other long-term assets		345		567
Total	$	1,307,590	$	1,109,043

The following table summarizes the contractual maturities of the short-term and long-term available-for-sale investments as of June 30, 2024 (in thousands):

	*Amortized Cost*		*Fair Value*
Due in less than 1 year	$	722,601	$	721,901
Due in 1 - 5 years		34,969		34,869
Due in greater than 5 years		350		345
Total	$	757,920	$	757,115

Gross realized gains and losses recognized on the sales of available-for-sale investments were not material for the periods presented.

The following tables summarize the unrealized gain and loss positions related to the available-for-sale investments (in thousands):

	*June 30, 2024*
	*Amortized Cost*		*Unrealized Gains*		*Unrealized Losses*			*Fair Value*
Money market funds	$	192,732	$	-	$	-		$	192,732
Certificates of deposit		165,120		-		-			165,120
Corporate debt securities		23,285		1		(557	)		22,729
U.S. treasuries and government agency bonds		569,165		5		(249	)		568,921
Auction-rate securities backed by student-loan notes		350		-		(5	)		345
Total	$	950,652	$	6	$	(811	)	$	949,847

	*December 31, 2023*
	*Amortized Cost*		*Unrealized Gains*		*Unrealized Losses*			*Fair Value*
Money market funds	$	135,514	$	-	$	-		$	135,514
Certificates of deposit		127,123		-		-			127,123
Corporate debt securities		96,636		4		(1,539	)		95,101
U.S. treasuries and government agency bonds		358,177		327		(95	)		358,409
Auction-rate securities backed by student-loan notes		574		-		(7	)		567
Total	$	718,024	$	331	$	(1,641	)	$	716,714

	*June 30, 2024*
	*Less than 12 Months*					*Greater than 12 Months*					*Total*
	*Fair Value*		*Unrealized Losses*			*Fair Value*		*Unrealized Losses*			*Fair Value*		*Unrealized Losses*
Corporate debt securities	$	-	$	-		$	22,278	$	(557	)	$	22,278	$	(557	)
U.S. treasuries and government agency bonds		474,947		(214	)		17,351		(35	)		492,298		(249	)
Auction-rate securities backed by student-loan notes		-		-			345		(5	)		345		(5	)
Total	$	474,947	$	(214	)	$	39,974	$	(597	)	$	514,921	$	(811	)

	*December 31, 2023*
	*Less than 12 Months*					*Greater than 12 Months*					*Total*
	*Fair Value*		*Unrealized Losses*			*Fair Value*		*Unrealized Losses*			*Fair Value*		*Unrealized Losses*
Corporate debt securities	$	20,792	$	(19	)	$	70,806	$	(1,520	)	$	91,598	$	(1,539	)
U.S. treasuries and government agency bonds		97,599		(95	)		-		-			97,599		(95	)
Auction-rate securities backed by student-loan notes		-		-			567		(7	)		567		(7	)
Total	$	118,391	$	(114	)	$	71,373	$	(1,527	)	$	189,764	$	(1,641	)

Restricted Cash

	*June 30,*		*December 31,*
	*2024*		*2023*
Cash and cash equivalents	$	550,475	$	527,843
Restricted cash included in other current assets		-		33,204
Restricted cash included in other long-term assets		125		134
Total cash, cash equivalents and restricted cash reported on the Condensed Consolidated Statements of Cash Flows	$	550,600	$	561,181

Note 11 - Fair Value Measurements

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Fair Value Disclosures [Text Block]

11. FAIR VALUE MEASUREMENTS

Fair Value Hierarchy

●	Level 1 —includes instruments with quoted prices in active markets for identical assets.
●	Level 2 —includes instruments for which the valuations are based upon quoted market prices in active markets involving similar assets or inputs other than quoted prices that are observable for the assets. The market inputs used to value these instruments generally consist of market yields, recently executed transactions, broker/dealer quotes or alternative pricing sources with reasonable levels of price transparency. Pricing sources may include industry standard data providers, security master files from large financial institutions, and other third-party sources used to determine a daily market value.
●	Level 3 —includes instruments for which the valuations are based on inputs that are unobservable and significant to the overall fair value measurement.

Financial Assets Measured at Fair Value on a Recurring Basis

The following tables summarize the fair value of the Company’s financial assets measured on a recurring basis (in thousands):

	*June 30, 2024*
	*Total*		*Level 1*		*Level 2*		*Level 3*
Money market funds	$	192,732	$	192,732	$	-	$	-
Certificates of deposit		165,120		-		165,120		-
Corporate debt securities		22,729		-		22,729		-
U.S. treasuries and government agency bonds		568,921		-		568,921		-
Auction-rate securities backed by student-loan notes		345		-		-		345
Mutual funds and money market funds under deferred compensation plan		58,928		58,928		-		-
Total	$	1,008,775	$	251,660	$	756,770	$	345

	*December 31, 2023*
	*Total*		*Level 1*		*Level 2*		*Level 3*
Money market funds	$	135,514	$	135,514	$	-	$	-
Certificates of deposit		127,123		-		127,123		-
Corporate debt securities		95,101		-		95,101		-
U.S. treasuries and government agency bonds		358,409		-		358,409		-
Auction-rate securities backed by student-loan notes		567		-		-		567
Mutual funds and money market funds under deferred compensation plan		54,836		54,836		-		-
Total	$	771,550	$	190,350	$	580,633	$	567

Redemptions and changes in the fair value of the auction-rate securities classified as Level 3 assets were not material for the periods presented.

Note 12 - Deferred Compensation Plan

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Compensation and Employee Benefit Plans [Text Block]

12. DEFERRED COMPENSATION PLAN

The following table summarizes the deferred compensation plan balances on the Condensed Consolidated Balance Sheets (in thousands):

	*June 30,*		*December 31,*
	*2024*		*2023*
Deferred compensation plan asset components:
Cash surrender value of corporate-owned life insurance policies	$	26,047	$	23,545
Fair value of mutual funds and money market funds		58,928		54,836
Total	$	84,975	$	78,381

Deferred compensation plan assets reported in:
Other long-term assets	$	84,975	$	78,381

Deferred compensation plan liabilities reported in:
Accrued compensation and related benefits (short-term)	$	7,534	$	384
Other long-term liabilities		80,115		80,903
Total	$	87,649	$	81,287

Note 13 - Other Income, Net

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Other Nonoperating Income and Expense [Text Block]

13. OTHER INCOME, NET

The components of other income, net, are as follows (in thousands):

	*Three Months Ended June 30,*					*Six Months Ended June 30,*
	*2024*			*2023*		*2024*			*2023*
Interest income	$	6,630		$	5,965	$	13,544		$	10,773
Amortization of discount (premium) on available-for-sale securities		5,917			204		10,040			(56	)
Other		(5,035	)		374		(6,532	)		1,123
Total	$	7,512		$	6,543	$	17,052		$	11,840

Note 14 - Income Taxes

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Income Tax Disclosure [Text Block]

14. INCOME TAXES

Note 15 - Accumulated Other Comprehensive Loss

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Comprehensive Income (Loss) Note [Text Block]

15. ACCUMULATED OTHER COMPREHENSIVE LOSS

The following table summarizes the changes in accumulated other comprehensive loss (in thousands):

	*Unrealized*
	*Losses on*			*Foreign Currency*
	*Available-for-Sale*			*Translation*
	*Securities*			*Adjustments*			*Total*
Balance as of January 1, 2024	$	(2,184	)	$	(24,878	)	$	(27,062	)
Other comprehensive income (loss) before reclassifications		87			(13,822	)		(13,735	)
Tax effect		248			-			248
Net current period other comprehensive income (loss)		335			(13,822	)		(13,487	)
Balance as of March 31, 2024		(1,849	)		(38,700	)		(40,549	)
Other comprehensive income (loss) before reclassifications		355			(4,313	)		(3,958	)
Amounts reclassified from accumulated other comprehensive loss		63			-			63
Tax effect		(50	)		-			(50	)
Net current period other comprehensive income (loss)		368			(4,313	)		(3,945	)
Balance as of June 30, 2024	$	(1,481	)	$	(43,013	)	$	(44,494	)

The amount reclassified from accumulated other comprehensive loss for the period presented was recorded in other income, net, on the Condensed Consolidated Statements of Operations.

Note 16 - Dividends and Dividend Equivalents

6 Months Ended

Jun. 30, 2024

Notes to Financial Statements

Dividends And Dividend Equivalents [Text Block]

16. DIVIDENDS AND DIVIDEND EQUIVALENTS

Cash Dividend Program

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Dividend declared per share	$	1.25	$	1.00	$	2.50	$	2.00
Total amount	$	60,872	$	47,530	$	121,706	$	94,860

As of June 30, 2024 and December 31, 2023, accrued dividends totaled $60.9 million and $47.9 million, respectively.

Cash Dividend Equivalent Rights

Insider Trading Arrangements	3 Months Ended	6 Months Ended
Insider Trading Arrangements	Jun. 30, 2024	Jun. 30, 2024
Insider Trading Arr Line Items
Material Terms of Trading Arrangement [Text Block]		Item 5. Other Information Certain of our executive officers have entered into trading plans pursuant to Rule 10b5-1(c) of the Securities Exchange Act of 1934, as amended. A trading plan is a written document that pre-establishes the amounts, prices and dates (or formula for determining the amounts, prices and dates) of future purchases or sales of our common stock, including the exercise and sale of shares acquired pursuant to the 2004 ESPP, and upon vesting of RSUs. During the three months ended June 30, 2024, no trading plans intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) were adopted, modified, or terminated, and no other written trading arrangements that are not intended to qualify for the Rule 10b5-1(c) affirmative defense were adopted, modified, or terminated.
Rule 10b5-1 Arrangement Adopted [Flag]	false
Rule 10b5-1 Arrangement Terminated [Flag]	false
Non-Rule 10b5-1 Arrangement Adopted [Flag]	false
Non-Rule 10b5-1 Arrangement Terminated [Flag]	false

Significant Accounting Policies (Policies)	6 Months Ended
Significant Accounting Policies (Policies)	Jun. 30, 2024
Accounting Policies [Abstract]
Goodwill and Intangible Assets, Policy [Policy Text Block]	Goodwill and Acquisition-Related Intangible Assets Goodwill represents the excess of fair value of purchase consideration over fair value of net tangible and identifiable intangible assets acquired as of the date of an acquisition. In-process research and development (“IPR&D”) assets represent the fair value of incomplete research and development (“R&D”) projects that had not reached technological feasibility as of the date of acquisition. IPR&D assets are initially capitalized at fair value as intangible assets with indefinite lives. When IPR&D projects are completed, they are reclassified as amortizable intangible assets and are amortized over their estimated useful lives. Alternatively, if IPR&D projects are abandoned, they are impaired and expensed as R&D costs. Acquisition-related intangible assets with finite lives consist of developed technologies, which are amortized on a straight-line basis over their estimated remaining useful lives. The amortization expense is recorded in cost of revenue in the Condensed Consolidated Statements of Operations.
Use of Estimates, Policy [Policy Text Block]	*Use of Estimates* The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of revenue and expenses during the reporting period. Significant estimates and assumptions used in these condensed consolidated financial statements primarily include those related to revenue recognition, inventory valuation, valuation of share-based awards, contingencies and income tax valuation allowances. Actual results could differ from these estimates and assumptions, and any such differences may be material to the Company’s condensed consolidated financial statements.
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements Not Yet Adopted as of June 30, 2024 In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures, which aims to improve disclosures regarding a public entity’s reportable segments, primarily through more comprehensive disclosures around significant segment expenses. The standard is effective for annual periods beginning January 1, 2024 and for interim periods beginning January 1, 2025, and should be applied retroactively to all prior periods presented. The Company is evaluating the potential effect that the updated standard will have on its financial statement disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which aims to improve an entity’s income tax disclosures around its effective rate reconciliation, income taxes paid, disaggregation of income before income taxes and income tax expense. The guidance will be effective for annual periods beginning January 1, 2025. The standard should be applied prospectively but retrospective application is permitted. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial statements.

Note 3 - Stock-based Compensation (Tables)

6 Months Ended

Jun. 30, 2024

Notes Tables

Share-Based Payment Arrangement, Cost by Plan [Table Text Block]

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Cost of revenue	$	1,611	$	1,150	$	3,009	$	2,297
Research and development		11,682		9,313		22,129		17,927
Selling, general and administrative (“SG&A”)		39,013		27,529		73,094		54,777
Total stock-based compensation expense	$	52,306	$	37,992	$	98,232	$	75,001
Tax benefit related to stock-based compensation ⁽¹⁾	$	798	$	663	$	1,506	$	1,086

Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]

	*Time-Based RSUs*					*PSUs and MPSUs*						*MSUs*					*Total*
				*Weighted-*						*Weighted-*					*Weighted-*					*Weighted-*
				*Average*						*Average*					*Average*					*Average*
				*Grant Date*						*Grant Date*					*Grant Date*					*Grant Date*
	*Number of*			*Fair Value*		*Number of*				*Fair Value*		*Number of*			*Fair Value*		*Number of*			*Fair Value*
	*Shares*			*Per Share*		*Shares*				*Per Share*		*Shares*			*Per Share*		*Shares*			*Per Share*
Outstanding at January 1, 2024		102		$	411.11		482			$	397.77		1,502		$	152.89		2,086		$	222.04
Granted		30		$	635.67		344		⁽¹⁾	$	593.33		-		$	-		374		$	596.68
Vested		(31	)	$	363.82		(77	)		$	307.93		(563	)	$	68.48		(671	)	$	109.62
Forfeited		(3	)	$	465.22		(1	)		$	396.40		(1	)	$	270.15		(5	)	$	412.40
Outstanding at June 30, 2024		98		$	493.16		748			$	496.84		938		$	203.33		1,784		$	342.19

Schedule of Share-Based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]

	*Six Months Ended June 30,*
	*2024*			*2023*
Expected term (in years)		0.5			0.5
Expected volatility		42.4	%		55.8	%
Risk-free interest rate		5.3	%		5.0	%
Dividend yield		0.7	%		0.8	%

Note 4 - Acquisition (Tables)

6 Months Ended

Jun. 30, 2024

Notes Tables

Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]

Inventory	$	720
Other tangible assets acquired, net of liabilities assumed		1,487
Intangible assets:
Developed technology		9,184
IPR&D		2,147
Total identifiable net assets acquired		13,538
Goodwill		19,860
Total net assets acquired	$	33,398

Note 5 - Balance Sheet Components (Tables)

6 Months Ended

Jun. 30, 2024

Notes Tables

Schedule of Inventory, Current [Table Text Block]

	*June 30,*		*December 31,*
	*2024*		*2023*
Raw materials	$	93,435	$	118,917
Work in process		164,116		112,750
Finished goods		169,200		152,035
Total	$	426,751	$	383,702

Schedule of Other Current Assets [Table Text Block]

	*June 30,*		*December 31,*
	*2024*		*2023*
Prepaid wafer purchases	$	60,000	$	-
Prepaid expenses		27,570		28,964
RSU tax withholding proceeds receivable		71		20,141
Other receivables		-		50,000
Restricted cash		-		33,204
Other		17,906		15,154
Total	$	105,547	$	147,463

Schedule of Other Assets, Noncurrent [Table Text Block]

	*June 30,*		*December 31,*
	*2024*		*2023*
Deferred compensation plan assets	$	84,975	$	78,381
Prepaid wafer purchases		60,000		120,000
Operating lease right-of-use (“ROU”) and related assets		33,681		8,355
Other		5,210		4,541
Total	$	183,866	$	211,277

Schedule of Accrued Liabilities [Table Text Block]

	*June 30,*		*December 31,*
	*2024*		*2023*
Dividends and dividend equivalents	$	62,524	$	57,697
Stock rotation and sales returns		21,716		18,843
Warranty		14,702		16,906
Customer prepayments		5,564		2,792
Accrued legal expenses		4,249		1,277
Income tax payable		9,641		8,063
Other		12,952		10,213
Total	$	131,348	$	115,791

Other Noncurrent Liabilities [Table Text Block]

	*June 30,*		*December 31,*
	*2024*		*2023*
Deferred compensation plan liabilities	$	80,115	$	80,903
Operating lease liabilities		13,045		5,565
Dividend equivalents		3,515		2,187
Total	$	96,675	$	88,655

Note 6 - Leases (Tables)

6 Months Ended

Jun. 30, 2024

Notes Tables

Lessee, Operating Lease, Balance Sheet Information [Table Text Block]

		*June 30,*		*December 31,*
	*Financial Statement Line Item*	*2024*		*2023*
Operating lease ROU assets	Other long-term assets	$	15,956	$	8,355

Operating lease liabilities	Other accrued liabilities	$	2,446	$	2,303
	Other long-term liabilities	$	13,045	$	5,565

Lease, Cost [Table Text Block]

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Lease costs:
Operating lease costs	$	1,014	$	759	$	1,911	$	1,475
Other		648		554		1,198		1,092
Total lease costs	$	1,662	$	1,313	$	3,109	$	2,567

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows for operating leases	$	1,027	$	774	$	1,700	$	1,638
ROU assets obtained in exchange for new operating lease liabilities	$	7,809	$	290	$	9,271	$	4,835

	*June 30,*			*December 31,*
	*2024*			*2023*
Weighted-average remaining lease term (in years)		12.1			4.7
Weighted-average discount rate		5.4	%		4.3	%

Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block]

2024 (remaining six months)	$	1,617
2025		2,997
2026		2,249
2027		2,012
2028		1,380
Thereafter		12,534
Total remaining lease payments		22,789
Less: imputed interest		(7,298	)
Total lease liabilities	$	15,491

Lessor, Operating Lease, Payment to be Received, Maturity [Table Text Block]

2024 (remaining six months)	$	525
2025		578
2026		402
2027		373
2028		384
Thereafter		129
Total	$	2,391

Note 7 - Net Income Per Share (Tables)

6 Months Ended

Jun. 30, 2024

Notes Tables

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Numerator:
Net income	$	100,366	$	99,504	$	192,907	$	209,306

Denominator:
Weighted-average outstanding shares — basic		48,687		47,489		48,660		47,361
Effect of dilutive securities		258		1,267		275		1,344
Weighted-average outstanding shares — diluted		48,945		48,756		48,935		48,705

Net income per share:
Basic	$	2.06	$	2.10	$	3.96	$	4.42
Diluted	$	2.05	$	2.04	$	3.94	$	4.30

Note 8 - Segment, Significant Customers and Geographic Information (Tables)

6 Months Ended

Jun. 30, 2024

Notes Tables

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

	Three Months Ended June 30,						Six Months Ended June 30,
Customer	2024			2023			2024			2023
Distributor A		38	%		22	%		40	%		21	%
Distributor B		17	%		20	%		15	%		21	%
Distributor C		*			11	%		*			10	%

	*June 30,*			*December 31,*
Customer	*2024*			*2023*
Distributor A		41	%		42	%
Distributor B		24	%		13	%
Distributor C		*			10	%

Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block]

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
Country or Region	*2024*		*2023*		*2024*		*2023*
China	$	282,514	$	216,172	$	545,554	$	441,224
Taiwan		127,396		70,212		227,846		119,045
South Korea		39,513		40,669		75,050		86,349
Europe		19,105		36,348		36,847		79,451
United States		13,927		27,571		28,747		58,588
Southeast Asia		11,352		21,708		24,591		48,140
Japan		13,552		28,288		26,500		59,103
Other		72		160		181		293
Total	$	507,431	$	441,128	$	965,316	$	892,193

Revenue from External Customers by Products and Services [Table Text Block]

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
Product Family	*2024*		*2023*		*2024*		*2023*
Direct Current (“DC”) to DC	$	501,302	$	418,175	$	947,367	$	843,356
Lighting Control		6,129		22,953		17,949		48,837
Total	$	507,431	$	441,128	$	965,316	$	892,193

The following is a summary of long-lived assets by geographic region (in thousands):

Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country [Table Text Block]

	*June 30,*		*December 31,*
Country	*2024*		*2023*
China	$	207,614	$	184,685
United States		124,000		119,430
Taiwan		37,071		39,419
Other		31,849		25,418
Total	$	400,534	$	368,952

Note 9 - Commitments and Contingencies (Tables)

6 Months Ended

Jun. 30, 2024

Notes Tables

Schedule of Product Warranty Liability [Table Text Block]

	*Three Months Ended June 30,*						*Six Months Ended June 30,*
	*2024*			*2023*			*2024*			*2023*
Balance at beginning of period	$	12,873		$	19,726		$	16,906		$	24,082
Warranties issued		2,225			580			2,325			942
Repairs, replacement and refund		(116	)		(1,581	)		(4,130	)		(2,253	)
Changes in liability for pre-existing warranties		(280	)		(1,071	)		(399	)		(5,117	)
Balance at end of period	$	14,702		$	17,654		$	14,702		$	17,654

Contractual Obligation, Fiscal Year Maturity [Table Text Block]

2024 (remaining six months)	$	151,590
2025		388,949
2026		1,572
2027		29,476
Total	$	571,587

Note 10 - Cash, Cash Equivalents, Investments and Restricted Cash (Tables)

6 Months Ended

Jun. 30, 2024

Notes Tables

Fair Value, by Balance Sheet Grouping [Table Text Block]

	*June 30,*		*December 31,*
	*2024*		*2023*
Cash	$	357,743	$	392,329
Money market funds		192,732		135,514
Certificates of deposit		165,120		127,123
Corporate debt securities		22,729		95,101
U.S. treasuries and government agency bonds		568,921		358,409
Auction-rate securities backed by student-loan notes		345		567
Total	$	1,307,590	$	1,109,043

	*June 30,*		*December 31,*
	*2024*		*2023*
Reported as:
Cash and cash equivalents	$	550,475	$	527,843
Short-term investments		756,770		580,633
Investment within other long-term assets		345		567
Total	$	1,307,590	$	1,109,043

Investments Classified by Contractual Maturity Date [Table Text Block]

	*Amortized Cost*		*Fair Value*
Due in less than 1 year	$	722,601	$	721,901
Due in 1 - 5 years		34,969		34,869
Due in greater than 5 years		350		345
Total	$	757,920	$	757,115

Unrealized Gain (Loss) on Investments [Table Text Block]

	*June 30, 2024*
	*Amortized Cost*		*Unrealized Gains*		*Unrealized Losses*			*Fair Value*
Money market funds	$	192,732	$	-	$	-		$	192,732
Certificates of deposit		165,120		-		-			165,120
Corporate debt securities		23,285		1		(557	)		22,729
U.S. treasuries and government agency bonds		569,165		5		(249	)		568,921
Auction-rate securities backed by student-loan notes		350		-		(5	)		345
Total	$	950,652	$	6	$	(811	)	$	949,847

	*December 31, 2023*
	*Amortized Cost*		*Unrealized Gains*		*Unrealized Losses*			*Fair Value*
Money market funds	$	135,514	$	-	$	-		$	135,514
Certificates of deposit		127,123		-		-			127,123
Corporate debt securities		96,636		4		(1,539	)		95,101
U.S. treasuries and government agency bonds		358,177		327		(95	)		358,409
Auction-rate securities backed by student-loan notes		574		-		(7	)		567
Total	$	718,024	$	331	$	(1,641	)	$	716,714

Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block]

	*June 30, 2024*
	*Less than 12 Months*					*Greater than 12 Months*					*Total*
	*Fair Value*		*Unrealized Losses*			*Fair Value*		*Unrealized Losses*			*Fair Value*		*Unrealized Losses*
Corporate debt securities	$	-	$	-		$	22,278	$	(557	)	$	22,278	$	(557	)
U.S. treasuries and government agency bonds		474,947		(214	)		17,351		(35	)		492,298		(249	)
Auction-rate securities backed by student-loan notes		-		-			345		(5	)		345		(5	)
Total	$	474,947	$	(214	)	$	39,974	$	(597	)	$	514,921	$	(811	)

	*December 31, 2023*
	*Less than 12 Months*					*Greater than 12 Months*					*Total*
	*Fair Value*		*Unrealized Losses*			*Fair Value*		*Unrealized Losses*			*Fair Value*		*Unrealized Losses*
Corporate debt securities	$	20,792	$	(19	)	$	70,806	$	(1,520	)	$	91,598	$	(1,539	)
U.S. treasuries and government agency bonds		97,599		(95	)		-		-			97,599		(95	)
Auction-rate securities backed by student-loan notes		-		-			567		(7	)		567		(7	)
Total	$	118,391	$	(114	)	$	71,373	$	(1,527	)	$	189,764	$	(1,641	)

Restrictions on Cash and Cash Equivalents [Table Text Block]

	*June 30,*		*December 31,*
	*2024*		*2023*
Cash and cash equivalents	$	550,475	$	527,843
Restricted cash included in other current assets		-		33,204
Restricted cash included in other long-term assets		125		134
Total cash, cash equivalents and restricted cash reported on the Condensed Consolidated Statements of Cash Flows	$	550,600	$	561,181

Note 11 - Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2024

Notes Tables

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	*June 30, 2024*
	*Total*		*Level 1*		*Level 2*		*Level 3*
Money market funds	$	192,732	$	192,732	$	-	$	-
Certificates of deposit		165,120		-		165,120		-
Corporate debt securities		22,729		-		22,729		-
U.S. treasuries and government agency bonds		568,921		-		568,921		-
Auction-rate securities backed by student-loan notes		345		-		-		345
Mutual funds and money market funds under deferred compensation plan		58,928		58,928		-		-
Total	$	1,008,775	$	251,660	$	756,770	$	345

	*December 31, 2023*
	*Total*		*Level 1*		*Level 2*		*Level 3*
Money market funds	$	135,514	$	135,514	$	-	$	-
Certificates of deposit		127,123		-		127,123		-
Corporate debt securities		95,101		-		95,101		-
U.S. treasuries and government agency bonds		358,409		-		358,409		-
Auction-rate securities backed by student-loan notes		567		-		-		567
Mutual funds and money market funds under deferred compensation plan		54,836		54,836		-		-
Total	$	771,550	$	190,350	$	580,633	$	567

Note 12 - Deferred Compensation Plan (Tables)

6 Months Ended

Jun. 30, 2024

Notes Tables

Schedule of Deferred Compensation Arrangement with Individual, Excluding Share-Based Payments and Postretirement Benefits by Title of Individual and Type of Deferred Compensation [Table Text Block]

	*June 30,*		*December 31,*
	*2024*		*2023*
Deferred compensation plan asset components:
Cash surrender value of corporate-owned life insurance policies	$	26,047	$	23,545
Fair value of mutual funds and money market funds		58,928		54,836
Total	$	84,975	$	78,381

Deferred compensation plan assets reported in:
Other long-term assets	$	84,975	$	78,381

Deferred compensation plan liabilities reported in:
Accrued compensation and related benefits (short-term)	$	7,534	$	384
Other long-term liabilities		80,115		80,903
Total	$	87,649	$	81,287

Note 13 - Other Income, Net (Tables)

6 Months Ended

Jun. 30, 2024

Notes Tables

Schedule of Other Nonoperating Income (Expense) [Table Text Block]

	*Three Months Ended June 30,*					*Six Months Ended June 30,*
	*2024*			*2023*		*2024*			*2023*
Interest income	$	6,630		$	5,965	$	13,544		$	10,773
Amortization of discount (premium) on available-for-sale securities		5,917			204		10,040			(56	)
Other		(5,035	)		374		(6,532	)		1,123
Total	$	7,512		$	6,543	$	17,052		$	11,840

Note 15 - Accumulated Other Comprehensive Loss (Tables)

6 Months Ended

Jun. 30, 2024

Notes Tables

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

	*Unrealized*
	*Losses on*			*Foreign Currency*
	*Available-for-Sale*			*Translation*
	*Securities*			*Adjustments*			*Total*
Balance as of January 1, 2024	$	(2,184	)	$	(24,878	)	$	(27,062	)
Other comprehensive income (loss) before reclassifications		87			(13,822	)		(13,735	)
Tax effect		248			-			248
Net current period other comprehensive income (loss)		335			(13,822	)		(13,487	)
Balance as of March 31, 2024		(1,849	)		(38,700	)		(40,549	)
Other comprehensive income (loss) before reclassifications		355			(4,313	)		(3,958	)
Amounts reclassified from accumulated other comprehensive loss		63			-			63
Tax effect		(50	)		-			(50	)
Net current period other comprehensive income (loss)		368			(4,313	)		(3,945	)
Balance as of June 30, 2024	$	(1,481	)	$	(43,013	)	$	(44,494	)

Note 16 - Dividends and Dividend Equivalents (Tables)

6 Months Ended

Jun. 30, 2024

Notes Tables

Dividends Declared [Table Text Block]

	*Three Months Ended June 30,*				*Six Months Ended June 30,*
	*2024*		*2023*		*2024*		*2023*
Dividend declared per share	$	1.25	$	1.00	$	2.50	$	2.00
Total amount	$	60,872	$	47,530	$	121,706	$	94,860

Note 2 - Revenue Recognition (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Contract with Customer, Liability, Current	$ 5,564		$ 5,564		$ 2,792
Minimum [Member]
Contract with Customer, Payment Term (Day)			30 days
Maximum [Member]
Contract with Customer, Payment Term (Day)			90 days
Certain Customers in China [Member]
Contract with Customer, Payment Term Required Prior to Shipping Products (Week)			14 days
Certain Customers in China [Member] \| Accrued Liabilities, Current [Member]
Contract with Customer, Liability, Current	$ 5,600		$ 5,600		$ 2,800
Product [Member]
Percentage of Revenue	99.00%	99.00%	99.00%	99.00%
Product Sales Through Distribution Arrangements [Member] \| Customer Concentration Risk [Member] \| Revenue Benchmark [Member]
Concentration Risk, Percentage	90.00%	80.00%	87.00%	80.00%

Note 3 - Stock-based Compensation (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 11, 2020	Feb. 29, 2024	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Aug. 16, 2023	Nov. 13, 2014
Share Price (in dollars per share)		$ 632.98	$ 821.68		$ 821.68
Proceeds from Stock Plans					$ 4,606	$ 3,737
Restricted Stock Units (RSUs) [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested			$ 25,500	$ 98,100	428,600	$ 239,700
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding			1,400,000		1,400,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount			$ 350,800		$ 350,800
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)					2 years
Time-Based RSUs [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)					30,000
Time-Based RSUs [Member] \| Employees [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)					30,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)					4 years
Time-Based RSUs [Member] \| Director [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)					1 year
PSU 2024 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Price Per Share Payable Upon Vesting of Equity Instruments Other than Options (in dollars per share)					$ 30
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term (Year)					3 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate					49.40%
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate					4.10%
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate					0.80%
PSU 2024 [Member] \| Executive Officer [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)		50,000
Maximum Stock Compensation Costs					$ 154,300
PSU 2024 [Member] \| Executive Officer [Member] \| Share-Based Payment Arrangement, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Maximum Percentage Allowed		300.00%
PSU 2024 [Member] \| Executive Officer [Member] \| Share-Based Payment Arrangement, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Maximum Percentage Allowed		100.00%
PSU 2024 [Member] \| Executive Officer [Member] \| Share-Based Payment Arrangement, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Maximum Percentage Allowed		50.00%
PSU 2024 [Member] \| Non-Executive Employees [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)		11,000
Maximum Stock Compensation Costs					$ 17,700
PSU 2024 [Member] \| Non-Executive Employees [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Maximum Percentage Allowed		300.00%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Minimum Percentage Allowed		200.00%
PSU 2024 [Member] \| Non-Executive Employees [Member] \| Vesting First Quarter of 2026 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		50.00%
The2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)								5,500,000
Amended and Restated 2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized (in shares)	10,500,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)			3,900,000		3,900,000
The 2004 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)							4,400,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)			4,400,000		4,400,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount			$ 400		$ 400
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares)			0	0	11,000	9,000
Employee Stock Purchase Plan Shares Issued, Intrinsic Value					$ 3,500	$ 700
Proceeds from Stock Plans					$ 4,600	$ 3,700

Note 3 - Stock-based Compensation - Stock-based Compensation Plan Expenses (Details) - USD ($)
$ in Thousands

3 Months Ended

6 Months Ended

Jun. 30, 2024

Jun. 30, 2023

Jun. 30, 2024

Jun. 30, 2023

Share based compensation expense

$ 52,306

$ 37,992

$ 98,232

$ 75,001

^[1]

798

663

1,506

1,086

Cost of Sales [Member]

Share based compensation expense

1,611

1,150

3,009

2,297

Research and Development Expense [Member]

Share based compensation expense

11,682

9,313

22,129

17,927

Selling, General and Administrative Expenses [Member]

Share based compensation expense

$ 39,013

$ 27,529

$ 73,094

$ 54,777

[1]

Note 3 - Stock-based Compensation - RSU Summary (Details)
shares in Thousands

6 Months Ended

Jun. 30, 2024

$ / shares

Time-Based RSUs [Member]

Balance (in shares) | shares

102

Outstanding, weighted average (in dollars per share) | $ / shares

$ 411.11

Granted (in shares) | shares

Granted, weighted average (in dollars per share) | $ / shares

$ 635.67

Vested (in shares) | shares

(31)

Vested, weighted average (in dollars per share) | $ / shares

$ 363.82

Forfeited (in shares) | shares

(3)

Forfeited, weighted average (in dollars per share) | $ / shares

$ 465.22

Balance (in shares) | shares

Outstanding, weighted average (in dollars per share) | $ / shares

$ 493.16

PSUs and MPSUs [Member]

Balance (in shares) | shares

482

Outstanding, weighted average (in dollars per share) | $ / shares

$ 397,770

Granted (in shares) | shares

344

^[1]

Granted, weighted average (in dollars per share) | $ / shares

$ 593.33

Vested (in shares) | shares

(77)

Vested, weighted average (in dollars per share) | $ / shares

$ 307.93

Forfeited (in shares) | shares

(1)

Forfeited, weighted average (in dollars per share) | $ / shares

$ 396.4

Balance (in shares) | shares

748

Outstanding, weighted average (in dollars per share) | $ / shares

$ 496.84

MSUs [Member]

Balance (in shares) | shares

1,502

Outstanding, weighted average (in dollars per share) | $ / shares

$ 152.89

Granted (in shares) | shares

Granted, weighted average (in dollars per share) | $ / shares

$ 0

Vested (in shares) | shares

(563)

Vested, weighted average (in dollars per share) | $ / shares

$ 68.48

Forfeited (in shares) | shares

(1)

Forfeited, weighted average (in dollars per share) | $ / shares

$ 270.15

Balance (in shares) | shares

938

Outstanding, weighted average (in dollars per share) | $ / shares

$ 203.33

Time-Based RSUs PSUs MSUs [Member]

Balance (in shares) | shares

2,086

Outstanding, weighted average (in dollars per share) | $ / shares

$ 222.04

Granted (in shares) | shares

374

Granted, weighted average (in dollars per share) | $ / shares

$ 596.68

Vested (in shares) | shares

(671)

Vested, weighted average (in dollars per share) | $ / shares

$ 109.62

Forfeited (in shares) | shares

(5)

Forfeited, weighted average (in dollars per share) | $ / shares

$ 412.4

Balance (in shares) | shares

1,784

Outstanding, weighted average (in dollars per share) | $ / shares

$ 342.19

[1]	Amount reflects the number of awards that may ultimately be earned based on management's probability assessment of the achievement of performance conditions at each reporting period.

Note 3 - Stock-based Compensation - Valuation Assumptions (Details) - 2004 Employee Stock Plan [Member] - Employee Stock Purchase Plan [Member]	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Expected term (Year)	6 months	6 months
Expected volatility	42.40%	55.80%
Risk-free interest rate	5.30%	5.00%
Dividend yield	0.70%	0.80%

Note 4 - Acquisition (Details Textual) - Axign [Member] - USD ($) $ in Millions	Jan. 03, 2024	Jun. 30, 2024
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Business Combination, Consideration Transferred	$ 33.4
Payment to Acquire Business Held in Escrow	$ 3.8
Business Acquisition, Transaction Costs		$ 0.4

Note 4 - Acquisitions - Preliminary Purchase Price Allocation (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Jan. 03, 2024	Dec. 31, 2023
Goodwill	$ 26,080		$ 6,571
Axign [Member]
Inventory		$ 720
Other tangible assets acquired, net of liabilities assumed		1,487
Developed technology		9,184
IPR&D		2,147
Total identifiable net assets acquired		13,538
Goodwill		19,860
Total net assets acquired		$ 33,398

Note 5 - Balance Sheet Components (Details Textual) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Prepaid Wafer Purchase, Current	$ 60,000
Other Receivables, Net, Current	$ 0	$ 50,000

Note 5 - Balance Sheet Components - Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Raw materials	$ 93,435	$ 118,917
Work in process	164,116	112,750
Finished goods	169,200	152,035
Total	$ 426,751	$ 383,702

Note 5 - Balance Sheet Components - Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Prepaid wafer purchases	$ 60,000	$ 0
Prepaid expenses	27,570	28,964
RSU tax withholding proceeds receivable	71	20,141
Other receivables	0	50,000
Restricted cash	0	33,204
Other	17,906	15,154
Total	$ 105,547	$ 147,463

Note 5 - Balance Sheet Components - Other Long-term Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Deferred compensation plan assets	$ 84,975	$ 78,381
Prepaid wafer purchases	60,000	120,000
Operating lease right-of-use (“ROU”) and related assets	33,681	8,355
Other	5,210	4,541
Total	$ 183,866	$ 211,277

Note 5 - Balance Sheet Components - Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Dividends and dividend equivalents	$ 62,524	$ 57,697
Stock rotation and sales returns	21,716	18,843
Warranty	14,702	16,906
Customer prepayments	5,564	2,792
Accrued legal expenses	4,249	1,277
Income tax payable	9,641	8,063
Other	12,952	10,213
Total	$ 131,348	$ 115,791

Note 5 - Balance Sheet Components - Other Long-term Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Deferred compensation plan liabilities	$ 80,115	$ 80,903
Operating lease liabilities	13,045	5,565
Dividend equivalents	3,515	2,187
Total	$ 96,675	$ 88,655

Note 6 - Leases (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
Note 6 - Leases (Details Textual) - USD ($) $ in Thousands	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Lessee, Operating Lease, Lease Not yet Commenced, Future Lease Obligations	$ 0		$ 0
Operating Lease, Lease Income, Lease Payments	$ 200	$ 300	$ 400	$ 800
Minimum [Member]
Lessee, Operating Lease, Remaining Lease Term (Year)	1 year		1 year
Lessor, Operating Lease, Remaining Lease Term (Year)			1 year
Maximum [Member]
Lessee, Operating Lease, Remaining Lease Term (Year)	20 years		20 years
Lessee, Operating Lease, Renewal Term (Year)	5 years		5 years
Lessor, Operating Lease, Remaining Lease Term (Year)			5 years
Lessor, Operating Lease, Renewal Term (Year)	5 years		5 years

Note 6 - Leases - Balance Sheet Information (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Operating lease ROU assets	$ 15,956	$ 8,355
Operating lease liabilities, current	2,446	2,303
Operating lease liabilities, noncurrent	$ 13,045	$ 5,565

Note 6 - Leases - Balance Sheet Information (Details) (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Assets [Abstract]
Other Assets, Noncurrent	$ 183,866	$ 211,277
Liabilities, Current [Abstract]
Accrued Liabilities, Current	131,348	115,791
Liabilities, Noncurrent [Abstract]
Other Liabilities, Noncurrent	$ 96,675	$ 88,655
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets, Noncurrent	Other Assets, Noncurrent
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued Liabilities, Current	Accrued Liabilities, Current
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent

Note 6 - Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Operating lease costs	$ 1,014	$ 759	$ 1,911	$ 1,475
Other	648	554	1,198	1,092
Total lease costs	1,662	1,313	3,109	2,567
Operating cash flows for operating leases	1,027	774	1,700	1,638
ROU assets obtained in exchange for new operating lease liabilities	$ 7,809	$ 290	$ 9,271	$ 4,835
Weighted-average remaining lease term (in years) (Year)	12 years 1 month 6 days		12 years 1 month 6 days		4 years 8 months 12 days
Weighted-average discount rate	5.40%		5.40%		4.30%

Note 6 - Leases - Maturities of Lease Liabilities (Details) $ in Thousands	Jun. 30, 2024 USD ($)
2024 (remaining six months)	$ 1,617
2025	2,997
2026	2,249
2027	2,012
2028	1,380
Thereafter	12,534
Total remaining lease payments	22,789
Less: imputed interest	(7,298)
Total lease liabilities	$ 15,491

Note 6 - Leases - Maturities of Income Related to Lease Payments (Details) $ in Thousands	Jun. 30, 2024 USD ($)
2024 (remaining six months)	$ 525
2025	578
2026	402
2027	373
2028	384
Thereafter	129
Total	$ 2,391

Note 7 - Net Income Per Share (Details Textual) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2024	Oct. 31, 2023
Stock Repurchased and Retired During Period, Shares (in shares)	6,300	12,400
Stock Repurchased and Retired During Period, Value	$ 4,550	$ 8,626
Maximum [Member]
Share Repurchase Program, Authorized, Amount			$ 640,000

Note 7 - Net Income Per Share - Net Income Per Share Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Net income	$ 100,366	$ 99,504	$ 192,907	$ 209,306
Weighted-average outstanding shares — basic (in shares)	48,687	47,489	48,660	47,361
Effect of dilutive securities (in shares)	258	1,267	275	1,344
Weighted-average outstanding shares — diluted (in shares)	48,945	48,756	48,935	48,705
Earnings per share, basic (in dollars per share)	$ 2.06	$ 2.1	$ 3.96	$ 4.42
Earnings per share, diluted (in dollars per share)	$ 2.05	$ 2.04	$ 3.94	$ 4.3

Note 8 - Segment, Significant Customers and Geographic Information (Details Textual)	6 Months Ended
	Jun. 30, 2024
Number of Reportable Segments	1

Note 8 - Segment, Significant Customers and Geographic Information - Customers with Sales and Accounts Receivable Greater Than 10% (Details) - Customer Concentration Risk [Member]	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenue Benchmark [Member] \| Distributor A [Member]
Concentration risk	38.00%	22.00%	40.00%	21.00%
Revenue Benchmark [Member] \| Distributor B [Member]
Concentration risk	17.00%	20.00%	15.00%	21.00%
Revenue Benchmark [Member] \| Distributor C [Member]
Concentration risk		11.00%		10.00%
Accounts Receivable [Member] \| Distributor A [Member]
Concentration risk			41.00%	42.00%
Accounts Receivable [Member] \| Distributor B [Member]
Concentration risk			24.00%	13.00%
Accounts Receivable [Member] \| Distributor C [Member]
Concentration risk				10.00%

Note 8 - Segment, Significant Customers and Geographic Information - Revenue By Region (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenue	$ 507,431	$ 441,128	$ 965,316	$ 892,193
CHINA
Revenue	282,514	216,172	545,554	441,224
TAIWAN
Revenue	127,396	70,212	227,846	119,045
KOREA, REPUBLIC OF
Revenue	39,513	40,669	75,050	86,349
Europe [Member]
Revenue	19,105	36,348	36,847	79,451
UNITED STATES
Revenue	13,927	27,571	28,747	58,588
South East Asia [Member]
Revenue	11,352	21,708	24,591	48,140
JAPAN
Revenue	13,552	28,288	26,500	59,103
Other Region [Member]
Revenue	$ 72	$ 160	$ 181	$ 293

Note 8 - Segment, Significant Customers and Geographic Information - Revenue By Product Family (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenue	$ 507,431	$ 441,128	$ 965,316	$ 892,193
DC To DC Products [Member]
Revenue	501,302	418,175	947,367	843,356
Lighting Control Products [Member]
Revenue	$ 6,129	$ 22,953	$ 17,949	$ 48,837

Note 8 - Segment, Significant Customers and Geographic Information - Long Lived Assets By Geographic Region (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Long lived assets by region	$ 400,534	$ 368,952
CHINA
Long lived assets by region	207,614	184,685
UNITED STATES
Long lived assets by region	124,000	119,430
TAIWAN
Long lived assets by region	37,071	39,419
Other Region [Member]
Long lived assets by region	$ 31,849	$ 25,418

Note 9 - Commitments and Contingencies (Details Textual) $ in Thousands	6 Months Ended
	Jun. 30, 2024 USD ($)
Purchase Obligation	$ 571,587
Prepaid Wafer Purchase, Current	60,000
Long-term Supply Agreement [Member]
Purchase Obligation	$ 120,000
Minimum [Member]
Warranty Term (Year)	1 year
Maximum [Member]
Warranty Term (Year)	2 years

Note 9 - Commitments and Contingencies - Changes in Warranty Reserve (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Balance	$ 12,873	$ 19,726	$ 16,906	$ 24,082
Warranties issued	2,225	580	2,325	942
Repairs, replacement and refund	(116)	(1,581)	(4,130)	(2,253)
Changes in liability for pre-existing warranties	(280)	(1,071)	(399)	(5,117)
Balance	$ 14,702	$ 17,654	$ 14,702	$ 17,654

Note 9 - Commitments and Contingencies - Estimated Future Unconditional Purchase Commitments (Details) $ in Thousands	Jun. 30, 2024 USD ($)
2024 (remaining six months)	$ 151,590
2025	388,949
2026	1,572
2027	29,476
Total	$ 571,587

Note 10 - Cash, Cash Equivalents, Investments and Restricted Cash - Cash, Cash Equivalents, Short-term and Long-term Investments (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Cash	$ 357,743	$ 392,329
Money market funds	192,732	135,514
Certificates of deposit	165,120	127,123
U.S. treasuries and government agency bonds	568,921	358,409
Total	1,307,590	1,109,043
Cash and cash equivalents	550,475	527,843
Short-term investments	756,770	580,633
Investment within other long-term assets	345	567
Corporate Debt Securities [Member]
Available-for-sale securities	22,729	95,101
Auction Rate Securities [Member]
Available-for-sale securities	$ 345	$ 567

Note 10 - Cash, Cash Equivalents, Investments and Restricted Cash - Investment Maturity Classification (Details) $ in Thousands	Jun. 30, 2024 USD ($)
Due in less than 1 year, Amortized cost	$ 722,601
Due in less than 1 year, fair value	721,901
Due in 1 - 5 years, Amortized cost	34,969
Due in 1 - 5 years, fair value	34,869
Due in greater than 5 years, Amortized cost	350
Due in greater than 5 years, fair value	345
Total, Amortized cost	757,920
Total, fair value	$ 757,115

Note 10 - Cash, Cash Equivalents, Investments and Restricted Cash - Unrealized Gains and Losses on Investments (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Amortized Cost	$ 950,652	$ 718,024
Unrealized Gains	6	331
Unrealized Losses	(811)	(1,641)
Total Fair Value	949,847	716,714
Money Market Funds [Member]
Amortized Cost	192,732	135,514
Unrealized Gains	0	0
Unrealized Losses	0	0
Total Fair Value	192,732	135,514
Certificates of Deposit [Member]
Amortized Cost	165,120	127,123
Unrealized Gains	0	0
Unrealized Losses	0	0
Total Fair Value	165,120	127,123
Corporate Debt Securities [Member]
Amortized Cost	23,285	96,636
Unrealized Gains	1	4
Unrealized Losses	(557)	(1,539)
Total Fair Value	22,729	95,101
US Government Agencies Short-Term Debt Securities [Member]
Amortized Cost	569,165	358,177
Unrealized Gains	5	327
Unrealized Losses	(249)	(95)
Total Fair Value	568,921	358,409
Auction Rate Securities [Member]
Amortized Cost	350	574
Unrealized Gains	0	0
Unrealized Losses	(5)	(7)
Total Fair Value	$ 345	$ 567

Note 10 - Cash, Cash Equivalents, Investments and Restricted Cash - Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Continuous Unrealized Loss Position, Less than 12 Months	$ 474,947	$ 118,391
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(214)	(114)
Continuous Unrealized Loss Position, 12 Months or Longer	39,974	71,373
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(597)	(1,527)
Unrealized Loss Position, Total	514,921	189,764
Unrealized Loss Position, Accumulated Loss, Total	(811)	(1,641)
Corporate Debt Securities [Member]
Continuous Unrealized Loss Position, Less than 12 Months	0	20,792
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	(19)
Continuous Unrealized Loss Position, 12 Months or Longer	22,278	70,806
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(557)	(1,520)
Unrealized Loss Position, Total	22,278	91,598
Unrealized Loss Position, Accumulated Loss, Total	(557)	(1,539)
US Treasury and Government Short-Term Debt Securities [Member]
Continuous Unrealized Loss Position, Less than 12 Months	474,947
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(214)
Continuous Unrealized Loss Position, 12 Months or Longer	17,351
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(35)
Unrealized Loss Position, Total	492,298
Unrealized Loss Position, Accumulated Loss, Total	(249)
US Government Agencies Short-Term Debt Securities [Member]
Continuous Unrealized Loss Position, Less than 12 Months		97,599
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(95)
Continuous Unrealized Loss Position, 12 Months or Longer		0
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0
Unrealized Loss Position, Total		97,599
Unrealized Loss Position, Accumulated Loss, Total		(95)
Auction Rate Securities [Member]
Continuous Unrealized Loss Position, Less than 12 Months	0	0
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Continuous Unrealized Loss Position, 12 Months or Longer	345	567
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(5)	(7)
Unrealized Loss Position, Total	345	567
Unrealized Loss Position, Accumulated Loss, Total	$ (5)	$ (7)

Note 10 - Cash, Cash Equivalents, Investments and Restricted Cash - Restricted Cash (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023	Dec. 31, 2022
Cash and cash equivalents	$ 550,475	$ 527,843
Restricted cash	0	33,204
Restricted cash included in other long-term assets	125	134
Total cash, cash equivalents and restricted cash reported on the Condensed Consolidated Statements of Cash Flows	$ 550,600	$ 561,181	$ 507,084	$ 288,729

Note 11 - Fair Value Measurements - Financial Assets and Liabilities, Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Total Fair Value	$ 949,847	$ 716,714
Assets, fair value	1,008,775	771,550
Fair Value, Inputs, Level 1 [Member]
Assets, fair value	251,660	190,350
Fair Value, Inputs, Level 2 [Member]
Assets, fair value	756,770	580,633
Fair Value, Inputs, Level 3 [Member]
Assets, fair value	345	567
Money Market Funds [Member]
Total Fair Value	192,732	135,514
Money Market Funds [Member] \| Fair Value, Inputs, Level 1 [Member]
Total Fair Value	192,732	135,514
Money Market Funds [Member] \| Fair Value, Inputs, Level 2 [Member]
Total Fair Value	0	0
Money Market Funds [Member] \| Fair Value, Inputs, Level 3 [Member]
Total Fair Value	0	0
Certificates of Deposit [Member]
Total Fair Value	165,120	127,123
Certificates of Deposit [Member] \| Fair Value, Inputs, Level 1 [Member]
Total Fair Value	0	0
Certificates of Deposit [Member] \| Fair Value, Inputs, Level 2 [Member]
Total Fair Value	165,120	127,123
Certificates of Deposit [Member] \| Fair Value, Inputs, Level 3 [Member]
Total Fair Value	0	0
Corporate Debt Securities [Member]
Total Fair Value	22,729	95,101
Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Total Fair Value	0	0
Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Total Fair Value	22,729	95,101
Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Total Fair Value	0	0
US Government Agencies Short-Term Debt Securities [Member]
Total Fair Value	568,921	358,409
US Government Agencies Short-Term Debt Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Total Fair Value	0	0
US Government Agencies Short-Term Debt Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Total Fair Value	568,921	358,409
US Government Agencies Short-Term Debt Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Total Fair Value	0	0
Auction Rate Securities [Member]
Total Fair Value	345	567
Auction Rate Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Total Fair Value	0	0
Auction Rate Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Total Fair Value	0	0
Auction Rate Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Total Fair Value	345	567
Mutual Fund [Member]
Total Fair Value	58,928	54,836
Mutual Fund [Member] \| Fair Value, Inputs, Level 1 [Member]
Total Fair Value	58,928	54,836
Mutual Fund [Member] \| Fair Value, Inputs, Level 2 [Member]
Total Fair Value	0	0
Mutual Fund [Member] \| Fair Value, Inputs, Level 3 [Member]
Total Fair Value	$ 0	$ 0

Note 12 - Deferred Compensation Plan - Summary of Deferred Compensation Plan (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Deferred compensation plan assets	$ 84,975	$ 78,381
Deferred compensation plan liabilities	87,649	81,287
Other Long-term Assets [Member]
Deferred compensation plan assets	84,975	78,381
Accrued Compensation and Related Benefits [Member]
Deferred compensation plan liabilities	7,534	384
Other Long-term Liabilities [Member]
Deferred compensation plan liabilities	80,115	80,903
Cash Surrender Value [Member]
Deferred compensation plan assets	26,047	23,545
Mutual Funds and Money Market Funds, Fair Value [Member]
Deferred compensation plan assets	$ 58,928	$ 54,836

Note 13 - Other Income, Net - Interest and Other Income Components (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Interest income	$ 6,630	$ 5,965	$ 13,544	$ 10,773
Amortization of discount (premium) on available-for-sale securities	5,917	204	10,040	(56)
Other	(5,035)	374	(6,532)	1,123
Total	$ 7,512	$ 6,543	$ 17,052	$ 11,840

Note 14 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Tax Expense (Benefit)	$ 23,682	$ 19,364	$ 36,168	$ 39,135
Effective Income Tax Rate Reconciliation, Percent	19.10%	16.30%	15.80%	15.80%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			21.00%	21.00%

Note 15 - Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2024	Mar. 31, 2024
Balance	$ 2,113,557	$ 2,049,939
Balance	2,195,858	2,113,557
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Balance	(1,849)	(2,184)
Other comprehensive income (loss) before reclassifications	355	87
Tax effect	(50)	248
Amounts reclassified from accumulated other comprehensive loss	63
Other comprehensive loss, net of tax	368	335
Balance	(1,481)	(1,849)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	(38,700)	(24,878)
Other comprehensive income (loss) before reclassifications	(4,313)	(13,822)
Tax effect	0	0
Amounts reclassified from accumulated other comprehensive loss	0
Other comprehensive loss, net of tax	(4,313)	(13,822)
Balance	(43,013)	(38,700)
AOCI Attributable to Parent [Member]
Balance	(40,549)	(27,062)
Other comprehensive income (loss) before reclassifications	(3,958)	(13,735)
Tax effect	(50)	248
Amounts reclassified from accumulated other comprehensive loss	63
Other comprehensive loss, net of tax	(3,945)	(13,487)
Balance	$ (44,494)	$ (40,549)

Note 16 - Dividends and Dividend Equivalents (Details Textual) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Dividends Payable, Current	$ 60.9	$ 47.9
Accrued Dividend Equivalents	$ 5.2	$ 11.9

Note 16 - Dividends and Dividend Equivalents - Cash Dividends (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Dividend declared per share (in dollars per share)	$ 1.25	$ 1	$ 2.5	$ 2
Total amount	$ 60,872	$ 47,530	$ 121,706	$ 94,860