Monolithic Power Systems (MPWR) 10-Q 6 Nov 24 2024 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2024	Oct. 30, 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	Q3
Document Fiscal Year Focus	2024
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 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		48,780,000

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 700,347	$ 527,843
Short-term investments	762,003	580,633
Accounts receivable, net	164,704	179,858
Inventories	424,942	383,702
Other current assets	108,454	147,463
Total current assets	2,160,450	1,819,499
Property and equipment, net	436,265	368,952
Acquisition-related intangible assets, net	10,225	0
Goodwill	26,080	6,571
Deferred tax assets, net	30,697	28,054
Other Assets, Noncurrent	191,023	211,277
Total assets	2,854,740	2,434,353
Liabilities, Current [Abstract]
Accounts payable	115,865	62,958
Accrued compensation and related benefits	81,292	56,286
Other accrued liabilities	139,431	115,791
Total current liabilities	336,588	235,035
Income tax liabilities	64,656	60,724
Other long-term liabilities	101,806	88,655
Total liabilities	503,050	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: 48,779 and 48,028, respectively	1,274,127	1,129,937
Retained earnings	1,098,759	947,064
Accumulated other comprehensive loss	(21,196)	(27,062)
Total stockholders’ equity	2,351,690	2,049,939
Total liabilities and stockholders’ equity	$ 2,854,740	$ 2,434,353

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares shares in Thousands	Sep. 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)	48,779	48,028
Common stock, shares outstanding (in shares)	48,779	48,028

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Revenue	$ 620,119	$ 474,867	$ 1,585,435	$ 1,367,060
Cost of revenue	276,676	211,326	708,973	597,064
Gross profit	343,443	263,541	876,462	769,996
Operating expenses:
Research and development	85,051	64,787	238,986	192,184
Selling, general and administrative	94,364	63,188	261,425	205,645
Total operating expenses	179,415	127,975	500,411	397,829
Operating income	164,028	135,566	376,051	372,167
Other income, net	10,278	2,289	27,330	14,129
Income before income taxes	174,306	137,855	403,381	386,296
Income tax expense	29,876	16,692	66,044	55,827
Net income	$ 144,430	$ 121,163	$ 337,337	$ 330,469
Net income per share
Basic (in dollars per share)	$ 2.96	$ 2.54	$ 6.93	$ 6.96
Diluted (in dollars per share)	$ 2.95	$ 2.48	$ 6.89	$ 6.78
Weighted-average shares outstanding:
Basic (in shares)	48,757	47,780	48,692	47,501
Diluted (in shares)	48,964	48,792	48,945	48,734

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Net income	$ 144,430	$ 121,163	$ 337,337	$ 330,469
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	22,321	(4,838)	4,186	(28,099)
Changes in unrealized gains and losses on available-for-sale securities, net of tax of $37, $156, $(161) and $625, respectively	977	1,132	1,680	4,073
Other comprehensive income (loss), net of tax:	23,298	(3,706)	5,866	(24,026)
Comprehensive income	$ 167,728	$ 117,457	$ 343,203	$ 306,443

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (Parentheticals) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Change in unrealized gain (loss) on available-for-sale securities, tax	$ 37	$ 156	$ (161)	$ 625

Condensed Consolidated Statem_4

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	330,469	0	330,469
Other comprehensive income	0	0	(24,026)	(24,026)
Dividends and dividend equivalents declared	$ 0	(147,474)	0	(147,474)
Common stock issued under the employee equity incentive plan (in shares)	786,000
Common stock issued under the employee equity incentive plan	$ 1,118	0	0	1,118
Common stock issued under the employee stock purchase plan (in shares)	18,000
Common stock issued under the employee stock purchase plan	$ 7,568	0	0	7,568
Stock-based compensation expense	$ 108,607	0	0	108,607
Balance (in shares) at Sep. 30, 2023	47,911,000
Balance at Sep. 30, 2023	$ 1,092,569	899,398	(47,103)	1,944,864
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
Net income	0	121,163	0	121,163
Other comprehensive income	0	0	(3,706)	(3,706)
Dividends and dividend equivalents declared	$ 0	(49,121)	0	(49,121)
Common stock issued under the employee equity incentive plan (in shares)	291,000
Common stock issued under the employee equity incentive plan	$ 4	0	0	4
Common stock issued under the employee stock purchase plan (in shares)	9,000
Common stock issued under the employee stock purchase plan	$ 3,831	0	0	3,831
Stock-based compensation expense	$ 33,604	0	0	33,604
Balance (in shares) at Sep. 30, 2023	47,911,000
Balance at Sep. 30, 2023	$ 1,092,569	899,398	(47,103)	$ 1,944,864
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	337,337	0	337,337
Other comprehensive income	0	0	5,866	5,866
Dividends and dividend equivalents declared	$ 0	(185,642)	0	(185,642)
Common stock issued under the employee equity incentive plan (in shares)	752,000
Common stock issued under the employee equity incentive plan	$ 0	0	0	0
Common stock issued under the employee stock purchase plan (in shares)	18,000
Common stock issued under the employee stock purchase plan	$ 8,727	0	0	$ 8,727
Repurchases of common stock (in shares)	(19,000)			(19,000)
Repurchases of common stock	$ (14,160)	0	0	$ (14,160)
Stock-based compensation expense	$ 149,623	0	0	$ 149,623
Balance (in shares) at Sep. 30, 2024	48,779,000			48,779,000
Balance at Sep. 30, 2024	$ 1,274,127	1,098,759	(21,196)	$ 2,351,690
Balance (in shares) at Jun. 30, 2024	48,698,000
Balance at Jun. 30, 2024	$ 1,224,144	1,016,208	(44,494)	2,195,858
Net income	0	144,430	0	144,430
Other comprehensive income	0	0	23,298	23,298
Dividends and dividend equivalents declared	$ 0	(61,879)	0	(61,879)
Common stock issued under the employee equity incentive plan (in shares)	81,000
Common stock issued under the employee equity incentive plan	$ 0	0	0	0
Common stock issued under the employee stock purchase plan (in shares)	7,000
Common stock issued under the employee stock purchase plan	$ 4,121			$ 4,121
Repurchases of common stock (in shares)	(7,000)			(6,000)
Repurchases of common stock	$ (5,534)	0	0	$ (5,534)
Stock-based compensation expense	$ 51,396	0	0	$ 51,396
Balance (in shares) at Sep. 30, 2024	48,779,000			48,779,000
Balance at Sep. 30, 2024	$ 1,274,127	$ 1,098,759	$ (21,196)	$ 2,351,690

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parentheticals) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Dividends and dividend equivalents declared per share (in dollars per share)	$ 1.25	$ 1	$ 3.75	$ 3

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities:
Net income	$ 337,337	$ 330,469
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	26,387	29,940
Amortization of discount on available-for-sale securities	(16,684)	(1,591)
Gain on deferred compensation plan investments	(9,180)	(3,411)
Deferred taxes, net	(6,598)	10,927
Stock-based compensation expense	149,630	108,603
Other	50	(1,447)
Changes in operating assets and liabilities:
Accounts receivable	15,148	(3,103)
Inventories	(40,535)	49,989
Other assets	57,781	(21,423)
Accounts payable	44,210	6,915
Accrued compensation and related benefits	24,450	(22,355)
Income tax liabilities	13,345	(12,797)
Other accrued liabilities	25,388	14,184
Net cash provided by operating activities	620,729	484,900
Cash flows from investing activities:
Purchases of property and equipment	(81,316)	(43,772)
Cash paid for an assumed lease	(18,175)	0
Purchases of investments	(941,451)	(492,638)
Maturities and sales of investments	779,861	328,181
Cash paid for acquisition, net of cash acquired	(33,283)	0
Contributions to deferred compensation plan, net	(1,764)	(4,466)
Net cash used in investing activities	(296,128)	(212,695)
Cash flows from financing activities:
Property and equipment purchased on extended payment terms	(2,654)	(2,732)
Proceeds from common stock issued under the employee equity incentive plan	0	1,118
Proceeds from common stock issued under the employee stock purchase plan	8,727	7,568
Repurchases of common stock	(14,160)	0
Dividends and dividend equivalents paid	(178,766)	(135,265)
Net cash used in financing activities	(186,853)	(129,311)
Effect of change in exchange rates	1,552	(10,323)
Net increase in cash, cash equivalents and restricted cash	139,300	132,571
Cash, cash equivalents and restricted cash, beginning of period	561,181	288,729
Cash, cash equivalents and restricted cash, end of period	700,481	421,300
Supplemental disclosures for cash flow information:
Cash paid for income taxes, net	58,614	73,678
Non-cash investing and financing activities:
Liability accrued for property and equipment purchases	9,577	2,893
Liability accrued for dividends and dividend equivalents	$ 63,922	$ 52,509

Note 1 - Basis of Presentation

Note 1 - Basis of Presentation	9 Months Ended
	Sep. 30, 2024
Notes to Financial Statements
Significant Accounting Policies [Text Block]	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 Goodwill and Acquisition-Related Intangible Assets 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 September 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 In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures

Note 2 - Revenue Recognition

Note 2 - Revenue Recognition	9 Months Ended
	Sep. 30, 2024
Notes to Financial Statements
Revenue from Contract with Customer [Text Block]	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 nine months ended September 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 September 30, 2024 and 2023, 88% and 77%, respectively, of the Company’s product sales were made through distribution arrangements. For the nine months ended September 30, 2024 and 2023, 87% and 79%, 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. 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 nine 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 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.

Note 3 - Stock-based Compensati

Note 3 - Stock-based Compensation	9 Months Ended
	Sep. 30, 2024
Notes to Financial Statements
Share-Based Payment Arrangement [Text Block]	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 September 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 September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Cost of revenue $ 1,576 $ 1,020 $ 4,585 $ 3,317 Research and development 11,331 8,479 33,460 26,406 Selling, general and administrative (“SG&A”) 38,491 24,103 111,585 78,880 Total stock-based compensation expense $ 51,398 $ 33,602 $ 149,630 $ 108,603 Tax benefit related to stock-based compensation (1) $ 766 $ 667 $ 2,272 $ 1,753 (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 31 $ 643.98 344 (1) $ 593.33 - $ - 375 $ 597.56 Vested (39 ) $ 374.15 (150 ) $ 272.21 (563 ) $ 68.48 (752 ) $ 125.04 Forfeited (4 ) $ 471.15 (1 ) $ 400.96 (1 ) $ 270.15 (6 ) $ 419.22 Outstanding at September 30, 2024 90 $ 505.64 675 $ 525.43 938 $ 203.32 1,703 $ 346.88 (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. The intrinsic value related to vested RSUs was $65.7 million and $148.9 million for the three months ended September 30, 2024 and 2023, respectively. The intrinsic value related to vested RSUs was $494.4 million and $388.6 million for the nine months ended September 30, 2024 and 2023, respectively. As of September 30, 2024, the total intrinsic value of all outstanding RSUs was $1.6 billion, based on the closing stock price of $924.50. As of September 30, 2024, unamortized compensation expense related to all outstanding RSUs was $299.6 million with a weighted-average remaining recognition period of approximately two Time-Based RSUs: For the nine months ended September 30, 2024, the Compensation Committee granted 31,000 RSUs with service conditions to non-executive employees and non-employee directors. The RSUs generally vest over four one 2024 PSUs: In February 2024, the Compensation Committee granted 50,000 PSUs to the executive officers, which represent the target number of shares that can be earned based on the degree of achievement of three sets of independent 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 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. three 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. For the three months ended September 30, 2024 and 2023, 7,000 and 9,000 shares were issued under the 2004 ESPP, respectively. For the nine months ended September 30, 2024 and 2023, 18,000 and 18,000 shares were issued under the 2004 ESPP, respectively. As of September 30, 2024, 4.4 million shares were available for future issuance under the 2004 ESPP. The intrinsic value of the shares issued was $2.0 million and $0.7 million for the three months ended September 30, 2024 and 2023, respectively. The intrinsic value of the shares issued was $5.4 million and $1.4 million for the nine months ended September 30, 2024 and 2023, respectively. As of September 30, 2024, the unamortized expense was $1.4 million, which will be recognized through the first quarter of 2025. The Black-Scholes model was used to value the employee stock purchase rights with the following weighted-average assumptions: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Expected term (in years) 0.5 0.5 0.5 0.5 Expected volatility 47.8 % 50.8 % 45.1 % 53.3 % Risk-free interest rate 5.0 % 5.5 % 5.2 % 5.3 % Dividend yield 0.6 % 0.8 % 0.6 % 0.8 % Cash proceeds from the shares issued under the 2004 ESPP were $8.7 million and $7.6 million for the nine months ended September 30, 2024 and 2023, respectively.

Note 4 - Acquisition

Note 4 - Acquisition	9 Months Ended
	Sep. 30, 2024
Notes to Financial Statements
Business Combination Disclosure [Text Block]	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.

Note 5 - Balance Sheet Componen

Note 5 - Balance Sheet Components	9 Months Ended
	Sep. 30, 2024
Notes to Financial Statements
Supplemental Balance Sheet Disclosures [Text Block]	5. BALANCE SHEET COMPONENTS Inventories Inventories consist of the following (in thousands): September 30, December 31, 2024 2023 Raw materials $ 70,567 $ 118,917 Work in process 182,312 112,750 Finished goods 172,063 152,035 Total $ 424,942 $ 383,702 Other Current Assets Other current assets consist of the following (in thousands): September 30, December 31, 2024 2023 Prepaid wafer purchases (1) $ 60,000 $ - Prepaid expenses 31,379 28,964 RSU tax withholding proceeds receivable 54 20,141 Other receivables (1) - 50,000 Restricted cash (2) - 33,204 Other 17,021 15,154 Total $ 108,454 $ 147,463 (1) The Company held $60 million in prepaid wafer purchases as of September 30, 2024 related to deposits made to a supplier under a long-term wafer supply agreement. The Company held $50 million in other receivables as of December 31, 2023 associated with those deposits. See Note 9 for details about the supply agreement. (2) 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. Other Long-Term Assets Other long-term assets consist of the following (in thousands): September 30, December 31, 2024 2023 Deferred compensation plan assets $ 89,324 $ 78,381 Prepaid wafer purchases (1) 60,000 120,000 Operating lease right-of-use (“ROU”) and related assets (2) 35,026 8,355 Other 6,673 4,541 Total $ 191,023 $ 211,277 (1) 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. (2) The operating lease ROU and related assets as of September 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): September 30, December 31, 2024 2023 Dividends and dividend equivalents $ 62,564 $ 57,697 Stock rotation and sales returns 24,033 18,843 Warranty 14,344 16,906 Customer prepayments 6,315 2,792 Income tax payable 11,407 8,063 Other 20,768 11,490 Total $ 139,431 $ 115,791 Other Long-Term Liabilities Other long-term liabilities consist of the following (in thousands): September 30, December 31, 2024 2023 Deferred compensation plan liabilities $ 84,128 $ 80,903 Operating lease liabilities 13,482 5,565 Dividend equivalents 4,196 2,187 Total $ 101,806 $ 88,655

Note 6 - Leases

Note 6 - Leases	9 Months Ended
	Sep. 30, 2024
Notes to Financial Statements
Leases Disclosure [Text Block]	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 five The following table summarizes the balances of operating lease ROU assets and liabilities (in thousands): September 30, December 31, Financial Statement Line Item 2024 2023 Operating lease ROU assets Other long-term assets $ 17,522 $ 8,355 Operating lease liabilities Other accrued liabilities $ 2,814 $ 2,303 Other long-term liabilities $ 13,482 $ 5,565 The following tables summarize certain information related to the leases (in thousands, except percentages and years): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Lease costs: Operating lease costs $ 948 $ 852 $ 2,859 $ 2,327 Other 822 480 2,020 1,572 Total lease costs $ 1,770 $ 1,332 $ 4,879 $ 3,899 Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 1,704 $ 629 $ 3,404 $ 2,267 ROU assets obtained in exchange for new operating lease liabilities $ 2,339 $ 2,086 $ 11,610 $ 6,921 September 30, December 31, 2024 2023 Weighted-average remaining lease term (in years) 11.3 4.7 Weighted-average discount rate 5.4 % 4.3 % As of September 30, 2024, the maturities of the lease liabilities were as follows (in thousands): 2024 (remaining three months) $ 958 2025 3,326 2026 2,787 2027 2,298 2028 1,550 Thereafter 12,639 Total remaining lease payments 23,558 Less: imputed interest (7,262 ) Total lease liabilities $ 16,296 As of September 30, 2024 , not 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 five five For the three months ended September 30, 2024 and 2023, income related to lease payments was $0.3 million and $0.4 million, respectively. For the nine months ended September 30, 2024 and 2023, income related to lease payments was $0.7 million and $1.2 million, respectively. As of September 30, 2024, future income related to lease payments was as follows (in thousands): 2024 (remaining three months) $ 264 2025 583 2026 403 2027 373 2028 384 Thereafter 129 Total $ 2,136

Note 7 - Net Income Per Share

Note 7 - Net Income Per Share	9 Months Ended
	Sep. 30, 2024
Notes to Financial Statements
Earnings Per Share [Text Block]	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 September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Numerator: Net income $ 144,430 $ 121,163 $ 337,337 $ 330,469 Denominator: Weighted-average outstanding shares — basic 48,757 47,780 48,692 47,501 Effect of dilutive securities 207 1,012 253 1,233 Weighted-average outstanding shares — diluted 48,964 48,792 48,945 48,734 Net income per share: Basic $ 2.96 $ 2.54 $ 6.93 $ 6.96 Diluted $ 2.95 $ 2.48 $ 6.89 $ 6.78 Anti-dilutive common stock equivalents were not material in any of the periods presented. Stock Repurchase Program

Note 8 - Segment, Significant C

Note 8 - Segment, Significant Customers and Geographic Information	9 Months Ended
	Sep. 30, 2024
Notes to Financial Statements
Segment Reporting Disclosure [Text Block]	8. SEGMENT, SIGNIFICANT CUSTOMERS AND GEOGRAPHIC INFORMATION The Company operates in one 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 September 30, Nine Months Ended September 30, Customer 2024 2023 2024 2023 Distributor A 24 % 27 % 33 % 23 % Distributor B 25 % 21 % 19 % 21 % Distributor C * 11 % * 10 % * Represents less than 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: September 30, December 31, Customer 2024 2023 Distributor A 25 % 42 % Distributor B 25 % 13 % Distributor C 10 % 10 % The following is a summary of revenue by geographic region (in thousands): Three Months Ended September 30, Nine Months Ended September 30, Country or Region 2024 2023 2024 2023 China $ 310,472 $ 234,924 $ 856,026 $ 676,148 Taiwan 179,747 103,537 407,593 222,582 South Korea 51,815 41,698 126,865 128,047 Europe 25,145 29,827 61,992 109,278 United States 13,797 23,565 42,544 82,153 Southeast Asia 22,772 22,538 47,363 70,678 Japan 16,286 18,605 42,786 77,708 Other 85 173 266 466 Total $ 620,119 $ 474,867 $ 1,585,435 $ 1,367,060 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 September 30, Nine Months Ended September 30, Product Family 2024 2023 2024 2023 Direct Current (“DC”) to DC $ 616,105 $ 447,394 $ 1,563,472 $ 1,290,750 Lighting Control 4,014 27,473 21,963 76,310 Total $ 620,119 $ 474,867 $ 1,585,435 $ 1,367,060 The following is a summary of long-lived assets by geographic region (in thousands): September 30, December 31, Country 2024 2023 China $ 237,113 $ 184,685 United States 125,952 119,430 Taiwan 39,929 39,419 Other 33,271 25,418 Total $ 436,265 $ 368,952

Note 9 - Commitments and Contin

Note 9 - Commitments and Contingencies	9 Months Ended
	Sep. 30, 2024
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	9. COMMITMENTS AND CONTINGENCIES Product Warranties The Company generally provides either a one two The changes in warranty reserves are as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Balance at beginning of period $ 14,702 $ 17,654 $ 16,906 $ 24,082 Warranties issued 570 1,858 2,895 2,800 Repairs, replacement and refund (849 ) (367 ) (4,979 ) (2,619 ) Changes in liability for pre-existing warranties (79 ) (2,102 ) (478 ) (7,220 ) Balance at end of period $ 14,344 $ 17,043 $ 14,344 $ 17,043 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 September 30, 2024, the Company had remaining prepayments under this agreement of $120.0 million, of which $60.0 million was classified as short-term. Total estimated future unconditional purchase commitments to all suppliers and other parties, net of the $120.0 million prepayment, as of September 30, 2024 were as follows (in thousands): 2024 (remaining three months) $ 36,496 2025 518,513 2026 1,613 2027 30,248 Total $ 586,870 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 September 30, 2024 ,

Note 10 - Cash, Cash Equivalent

Note 10 - Cash, Cash Equivalents, Investments and Restricted Cash	9 Months Ended
	Sep. 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): September 30, December 31, 2024 2023 Cash $ 413,010 $ 392,329 Money market funds 282,883 135,514 Certificates of deposit 171,065 127,123 Corporate debt securities 14,236 95,101 U.S. treasuries and government agency bonds 581,156 358,409 Auction-rate securities backed by student-loan notes 173 567 Total $ 1,462,523 $ 1,109,043 September 30, December 31, 2024 2023 Reported as: Cash and cash equivalents $ 700,347 $ 527,843 Short-term investments 762,003 580,633 Investment within other long-term assets 173 567 Total $ 1,462,523 $ 1,109,043 The following table summarizes the contractual maturities of the short-term and long-term available-for-sale investments as of September 30, 2024 (in thousands): Amortized Cost Fair Value Due in less than 1 year $ 765,440 $ 765,683 Due in 1 - 5 years 805 774 Due in greater than 5 years 175 173 Total $ 766,420 $ 766,630 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): September 30, 2024 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Money market funds $ 282,883 $ - $ - $ 282,883 Certificates of deposit 171,065 - - 171,065 Corporate debt securities 14,522 - (286 ) 14,236 U.S. treasuries and government agency bonds 580,658 515 (17 ) 581,156 Auction-rate securities backed by student-loan notes 175 - (2 ) 173 Total $ 1,049,303 $ 515 $ (305 ) $ 1,049,513 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): September 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 $ - $ - $ 14,236 $ (286 ) $ 14,236 $ (286 ) U.S. treasuries and government agency bonds 45,331 (15 ) 4,883 (2 ) 50,214 (17 ) Auction-rate securities backed by student-loan notes - - 173 (2 ) 173 (2 ) Total $ 45,331 $ (15 ) $ 19,292 $ (290 ) $ 64,623 $ (305 ) 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 September 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. 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): September 30, December 31, 2024 2023 Cash and cash equivalents $ 700,347 $ 527,843 Restricted cash included in other current assets (1) - 33,204 Restricted cash included in other long-term assets (2) 134 134 Total cash, cash equivalents and restricted cash reported on the Condensed Consolidated Statements of Cash Flows $ 700,481 $ 561,181 (1) 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. (2) The restricted cash included in other long-term assets as of September 30, 2024 and December 31, 2023 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.

Note 11 - Fair Value Measuremen

Note 11 - Fair Value Measurements	9 Months Ended
	Sep. 30, 2024
Notes to Financial Statements
Fair Value Disclosures [Text Block]	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): September 30, 2024 Total Level 1 Level 2 Level 3 Money market funds $ 282,883 $ 282,883 $ - $ - Certificates of deposit 171,065 - 171,065 - Corporate debt securities 14,236 - 14,236 - U.S. treasuries and government agency bonds 581,156 - 581,156 - Auction-rate securities backed by student-loan notes 173 - - 173 Mutual funds and money market funds under deferred compensation plan 61,637 61,637 - - Total $ 1,111,150 $ 344,520 $ 766,457 $ 173 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

Note 12 - Deferred Compensation Plan	9 Months Ended
	Sep. 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): September 30, December 31, 2024 2023 Deferred compensation plan asset components: Cash surrender value of corporate-owned life insurance policies $ 27,687 $ 23,545 Fair value of mutual funds and money market funds 61,637 54,836 Total $ 89,324 $ 78,381 Deferred compensation plan assets reported in: Other long-term assets $ 89,324 $ 78,381 Deferred compensation plan liabilities reported in: Accrued compensation and related benefits (short-term) $ 8,012 $ 384 Other long-term liabilities 84,128 80,903 Total $ 92,140 $ 81,287

Note 13 - Other Income, Net

Note 13 - Other Income, Net	9 Months Ended
	Sep. 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 September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Interest income $ 6,805 $ 6,071 $ 20,349 $ 16,844 Amortization of discount on available-for-sale securities 6,644 1,647 16,684 1,591 Gain (loss) on deferred compensation plan investments 3,894 (1,611 ) 9,180 3,411 Charitable contributions (6,400 ) (3,850 ) (18,550 ) (9,650 ) Other (665 ) 32 (333 ) 1,933 Total $ 10,278 $ 2,289 $ 27,330 $ 14,129

Note 14 - Income Taxes

Note 14 - Income Taxes	9 Months Ended
	Sep. 30, 2024
Notes to Financial Statements
Income Tax Disclosure [Text Block]	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 September 30, 2024 was $29.9 million, or 17.1% of pre-tax income. The income tax expense for the nine months ended September 30, 2024 was $66.0 million, or 16.4% 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 September 30, 2023 was $16.7 million, or 12.1% of pre-tax income. The income tax expense for the nine months ended September 30, 2023 was $55.8 million, or 14.5% 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 ( “ ” In September 2024, a subsidiary of the Company was granted a tax credit with a ten-year life by a foreign jurisdiction. The tax credit may be utilized beginning in tax year 2025 to offset income tax liabilities in that jurisdiction, subject to various criteria as outlined by the granting authorities. As of September 30, 2024, the Company has evaluated the sources of income necessary to benefit from the tax credit and has determined that it currently does not meet the more likely than not criteria for realization of this deferred tax asset. As a result, the Company has recorded a full valuation allowance on this deferred tax asset. The Company is evaluating the steps necessary, some of which are not within its immediate control, to generate sufficient future taxable income in the required jurisdiction and will reassess the realizability of this deferred tax asset each reporting period.

Note 15 - Accumulated Other Com

Note 15 - Accumulated Other Comprehensive Loss	9 Months Ended
	Sep. 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 ) Other comprehensive income before reclassifications 1,014 22,321 23,335 Tax effect (37 ) - (37 ) Net current period other comprehensive income 977 22,321 23,298 Balance as of September 30, 2024 $ (504 ) $ (20,692 ) $ (21,196 ) 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 Dividen

Note 16 - Dividends and Dividend Equivalents	9 Months Ended
	Sep. 30, 2024
Notes to Financial Statements
Dividends And Dividend Equivalents [Text Block]	16. DIVIDENDS AND DIVIDEND EQUIVALENTS Cash Dividend Program The Company has a dividend program approved by its 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 September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Dividend declared per share $ 1.25 $ 1.00 $ 3.75 $ 3.00 Total amount $ 60,974 $ 47,832 $ 182,680 $ 142,692 As of September 30, 2024 and December 31, 2023, accrued dividends totaled $61.0 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 September 30, 2024 and December 31, 2023 ,

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2024 shares
ecd_TradingArrByIndTable
Non-Rule 10b5-1 Arrangement Terminated [Flag]	false
Non-Rule 10b5-1 Arrangement Adopted [Flag]	false
Victor K Lee [Member]
ecd_TradingArrByIndTable
Trading Arrangement, Securities Aggregate Available Amount	1,000
Trading Arrangement, Individual Name	Victor K. Lee
Trading Arrangement, Individual Title	Director
Trading Arrangement Adoption Date	August 21, 2024
Rule 10b5-1 Arrangement Terminated [Flag]	true
Trading Arrangement Termination Date	August 21, 2025
Rule 10b5-1 Arrangement Adopted [Flag]	true
Maurice Sciammas [Member]
ecd_TradingArrByIndTable
Trading Arrangement, Securities Aggregate Available Amount	19,000
Trading Arrangement, Individual Name	Maurice Sciammas
Trading Arrangement, Individual Title	Executive Vice President of Worldwide Sales and Marketing
Trading Arrangement Adoption Date	August 22, 2024
Rule 10b5-1 Arrangement Terminated [Flag]	true
Trading Arrangement Termination Date	August 29, 2025
Rule 10b5-1 Arrangement Adopted [Flag]	true
Michael Hsing [Member]
ecd_TradingArrByIndTable
Trading Arrangement, Securities Aggregate Available Amount	133,082
Trading Arrangement, Individual Name	Michael Hsing
Trading Arrangement, Individual Title	President, Chief Executive Officer and Director
Trading Arrangement Adoption Date	August 30, 2024
Rule 10b5-1 Arrangement Terminated [Flag]	true
Trading Arrangement Termination Date	December 31, 2025
Rule 10b5-1 Arrangement Adopted [Flag]	true
Saria Tseng [Member]
ecd_TradingArrByIndTable
Trading Arrangement, Securities Aggregate Available Amount	33,963
Trading Arrangement, Individual Name	Saria Tseng
Trading Arrangement, Individual Title	Executive Vice President, Strategic Corporate Development, General Counsel and Corporate Secretary
Trading Arrangement Adoption Date	August 30, 2024
Rule 10b5-1 Arrangement Terminated [Flag]	true
Trading Arrangement Termination Date	December 31, 2025
Rule 10b5-1 Arrangement Adopted [Flag]	true

Significant Accounting Policies

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Goodwill and Intangible Assets, Policy [Policy Text Block]	Goodwill and Acquisition-Related Intangible Assets
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 September 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 In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures

Note 3 - Stock-based Compensa_2

Note 3 - Stock-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2024
Notes Tables
Share-Based Payment Arrangement, Cost by Plan [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Cost of revenue $ 1,576 $ 1,020 $ 4,585 $ 3,317 Research and development 11,331 8,479 33,460 26,406 Selling, general and administrative (“SG&A”) 38,491 24,103 111,585 78,880 Total stock-based compensation expense $ 51,398 $ 33,602 $ 149,630 $ 108,603 Tax benefit related to stock-based compensation (1) $ 766 $ 667 $ 2,272 $ 1,753
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 31 $ 643.98 344 (1) $ 593.33 - $ - 375 $ 597.56 Vested (39 ) $ 374.15 (150 ) $ 272.21 (563 ) $ 68.48 (752 ) $ 125.04 Forfeited (4 ) $ 471.15 (1 ) $ 400.96 (1 ) $ 270.15 (6 ) $ 419.22 Outstanding at September 30, 2024 90 $ 505.64 675 $ 525.43 938 $ 203.32 1,703 $ 346.88
Schedule of Share-Based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Expected term (in years) 0.5 0.5 0.5 0.5 Expected volatility 47.8 % 50.8 % 45.1 % 53.3 % Risk-free interest rate 5.0 % 5.5 % 5.2 % 5.3 % Dividend yield 0.6 % 0.8 % 0.6 % 0.8 %

Note 4 - Acquisition (Tables)

Note 4 - Acquisition (Tables)	9 Months Ended
	Sep. 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 Compon_2

Note 5 - Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2024
Notes Tables
Schedule of Inventory, Current [Table Text Block]	September 30, December 31, 2024 2023 Raw materials $ 70,567 $ 118,917 Work in process 182,312 112,750 Finished goods 172,063 152,035 Total $ 424,942 $ 383,702
Schedule of Other Current Assets [Table Text Block]	September 30, December 31, 2024 2023 Prepaid wafer purchases (1) $ 60,000 $ - Prepaid expenses 31,379 28,964 RSU tax withholding proceeds receivable 54 20,141 Other receivables (1) - 50,000 Restricted cash (2) - 33,204 Other 17,021 15,154 Total $ 108,454 $ 147,463
Schedule of Other Assets, Noncurrent [Table Text Block]	September 30, December 31, 2024 2023 Deferred compensation plan assets $ 89,324 $ 78,381 Prepaid wafer purchases (1) 60,000 120,000 Operating lease right-of-use (“ROU”) and related assets (2) 35,026 8,355 Other 6,673 4,541 Total $ 191,023 $ 211,277
Schedule of Accrued Liabilities [Table Text Block]	September 30, December 31, 2024 2023 Dividends and dividend equivalents $ 62,564 $ 57,697 Stock rotation and sales returns 24,033 18,843 Warranty 14,344 16,906 Customer prepayments 6,315 2,792 Income tax payable 11,407 8,063 Other 20,768 11,490 Total $ 139,431 $ 115,791
Other Noncurrent Liabilities [Table Text Block]	September 30, December 31, 2024 2023 Deferred compensation plan liabilities $ 84,128 $ 80,903 Operating lease liabilities 13,482 5,565 Dividend equivalents 4,196 2,187 Total $ 101,806 $ 88,655

Note 6 - Leases (Tables)

Note 6 - Leases (Tables)	9 Months Ended
	Sep. 30, 2024
Notes Tables
Lessee, Operating Lease, Balance Sheet Information [Table Text Block]	September 30, December 31, Financial Statement Line Item 2024 2023 Operating lease ROU assets Other long-term assets $ 17,522 $ 8,355 Operating lease liabilities Other accrued liabilities $ 2,814 $ 2,303 Other long-term liabilities $ 13,482 $ 5,565
Lease, Cost [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Lease costs: Operating lease costs $ 948 $ 852 $ 2,859 $ 2,327 Other 822 480 2,020 1,572 Total lease costs $ 1,770 $ 1,332 $ 4,879 $ 3,899 Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 1,704 $ 629 $ 3,404 $ 2,267 ROU assets obtained in exchange for new operating lease liabilities $ 2,339 $ 2,086 $ 11,610 $ 6,921 September 30, December 31, 2024 2023 Weighted-average remaining lease term (in years) 11.3 4.7 Weighted-average discount rate 5.4 % 4.3 %
Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block]	2024 (remaining three months) $ 958 2025 3,326 2026 2,787 2027 2,298 2028 1,550 Thereafter 12,639 Total remaining lease payments 23,558 Less: imputed interest (7,262 ) Total lease liabilities $ 16,296
Lessor, Operating Lease, Payment to be Received, Maturity [Table Text Block]	2024 (remaining three months) $ 264 2025 583 2026 403 2027 373 2028 384 Thereafter 129 Total $ 2,136

Note 7 - Net Income Per Share (

Note 7 - Net Income Per Share (Tables)	9 Months Ended
	Sep. 30, 2024
Notes Tables
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Numerator: Net income $ 144,430 $ 121,163 $ 337,337 $ 330,469 Denominator: Weighted-average outstanding shares — basic 48,757 47,780 48,692 47,501 Effect of dilutive securities 207 1,012 253 1,233 Weighted-average outstanding shares — diluted 48,964 48,792 48,945 48,734 Net income per share: Basic $ 2.96 $ 2.54 $ 6.93 $ 6.96 Diluted $ 2.95 $ 2.48 $ 6.89 $ 6.78

Note 8 - Segment, Significant_2

Note 8 - Segment, Significant Customers and Geographic Information (Tables)	9 Months Ended
	Sep. 30, 2024
Notes Tables
Schedules of Concentration of Risk, by Risk Factor [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, Customer 2024 2023 2024 2023 Distributor A 24 % 27 % 33 % 23 % Distributor B 25 % 21 % 19 % 21 % Distributor C * 11 % * 10 % September 30, December 31, Customer 2024 2023 Distributor A 25 % 42 % Distributor B 25 % 13 % Distributor C 10 % 10 %
Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, Country or Region 2024 2023 2024 2023 China $ 310,472 $ 234,924 $ 856,026 $ 676,148 Taiwan 179,747 103,537 407,593 222,582 South Korea 51,815 41,698 126,865 128,047 Europe 25,145 29,827 61,992 109,278 United States 13,797 23,565 42,544 82,153 Southeast Asia 22,772 22,538 47,363 70,678 Japan 16,286 18,605 42,786 77,708 Other 85 173 266 466 Total $ 620,119 $ 474,867 $ 1,585,435 $ 1,367,060
Revenue from External Customers by Products and Services [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, Product Family 2024 2023 2024 2023 Direct Current (“DC”) to DC $ 616,105 $ 447,394 $ 1,563,472 $ 1,290,750 Lighting Control 4,014 27,473 21,963 76,310 Total $ 620,119 $ 474,867 $ 1,585,435 $ 1,367,060 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]	September 30, December 31, Country 2024 2023 China $ 237,113 $ 184,685 United States 125,952 119,430 Taiwan 39,929 39,419 Other 33,271 25,418 Total $ 436,265 $ 368,952

Note 9 - Commitments and Cont_2

Note 9 - Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2024
Notes Tables
Schedule of Product Warranty Liability [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Balance at beginning of period $ 14,702 $ 17,654 $ 16,906 $ 24,082 Warranties issued 570 1,858 2,895 2,800 Repairs, replacement and refund (849 ) (367 ) (4,979 ) (2,619 ) Changes in liability for pre-existing warranties (79 ) (2,102 ) (478 ) (7,220 ) Balance at end of period $ 14,344 $ 17,043 $ 14,344 $ 17,043
Contractual Obligation, Fiscal Year Maturity [Table Text Block]	2024 (remaining three months) $ 36,496 2025 518,513 2026 1,613 2027 30,248 Total $ 586,870

Note 10 - Cash, Cash Equivale_2

Note 10 - Cash, Cash Equivalents, Investments and Restricted Cash (Tables)	9 Months Ended
	Sep. 30, 2024
Notes Tables
Fair Value, by Balance Sheet Grouping [Table Text Block]	September 30, December 31, 2024 2023 Cash $ 413,010 $ 392,329 Money market funds 282,883 135,514 Certificates of deposit 171,065 127,123 Corporate debt securities 14,236 95,101 U.S. treasuries and government agency bonds 581,156 358,409 Auction-rate securities backed by student-loan notes 173 567 Total $ 1,462,523 $ 1,109,043 September 30, December 31, 2024 2023 Reported as: Cash and cash equivalents $ 700,347 $ 527,843 Short-term investments 762,003 580,633 Investment within other long-term assets 173 567 Total $ 1,462,523 $ 1,109,043
Investments Classified by Contractual Maturity Date [Table Text Block]	Amortized Cost Fair Value Due in less than 1 year $ 765,440 $ 765,683 Due in 1 - 5 years 805 774 Due in greater than 5 years 175 173 Total $ 766,420 $ 766,630
Unrealized Gain (Loss) on Investments [Table Text Block]	September 30, 2024 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Money market funds $ 282,883 $ - $ - $ 282,883 Certificates of deposit 171,065 - - 171,065 Corporate debt securities 14,522 - (286 ) 14,236 U.S. treasuries and government agency bonds 580,658 515 (17 ) 581,156 Auction-rate securities backed by student-loan notes 175 - (2 ) 173 Total $ 1,049,303 $ 515 $ (305 ) $ 1,049,513 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]	September 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 $ - $ - $ 14,236 $ (286 ) $ 14,236 $ (286 ) U.S. treasuries and government agency bonds 45,331 (15 ) 4,883 (2 ) 50,214 (17 ) Auction-rate securities backed by student-loan notes - - 173 (2 ) 173 (2 ) Total $ 45,331 $ (15 ) $ 19,292 $ (290 ) $ 64,623 $ (305 ) 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]	September 30, December 31, 2024 2023 Cash and cash equivalents $ 700,347 $ 527,843 Restricted cash included in other current assets (1) - 33,204 Restricted cash included in other long-term assets (2) 134 134 Total cash, cash equivalents and restricted cash reported on the Condensed Consolidated Statements of Cash Flows $ 700,481 $ 561,181

Note 11 - Fair Value Measurem_2

Note 11 - Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2024
Notes Tables
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	September 30, 2024 Total Level 1 Level 2 Level 3 Money market funds $ 282,883 $ 282,883 $ - $ - Certificates of deposit 171,065 - 171,065 - Corporate debt securities 14,236 - 14,236 - U.S. treasuries and government agency bonds 581,156 - 581,156 - Auction-rate securities backed by student-loan notes 173 - - 173 Mutual funds and money market funds under deferred compensation plan 61,637 61,637 - - Total $ 1,111,150 $ 344,520 $ 766,457 $ 173 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 Compensati_2

Note 12 - Deferred Compensation Plan (Tables)	9 Months Ended
	Sep. 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]	September 30, December 31, 2024 2023 Deferred compensation plan asset components: Cash surrender value of corporate-owned life insurance policies $ 27,687 $ 23,545 Fair value of mutual funds and money market funds 61,637 54,836 Total $ 89,324 $ 78,381 Deferred compensation plan assets reported in: Other long-term assets $ 89,324 $ 78,381 Deferred compensation plan liabilities reported in: Accrued compensation and related benefits (short-term) $ 8,012 $ 384 Other long-term liabilities 84,128 80,903 Total $ 92,140 $ 81,287

Note 13 - Other Income, Net (Ta

Note 13 - Other Income, Net (Tables)	9 Months Ended
	Sep. 30, 2024
Notes Tables
Schedule of Other Nonoperating Income (Expense) [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Interest income $ 6,805 $ 6,071 $ 20,349 $ 16,844 Amortization of discount on available-for-sale securities 6,644 1,647 16,684 1,591 Gain (loss) on deferred compensation plan investments 3,894 (1,611 ) 9,180 3,411 Charitable contributions (6,400 ) (3,850 ) (18,550 ) (9,650 ) Other (665 ) 32 (333 ) 1,933 Total $ 10,278 $ 2,289 $ 27,330 $ 14,129

Note 15 - Accumulated Other C_2

Note 15 - Accumulated Other Comprehensive Loss (Tables)	9 Months Ended
	Sep. 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 ) Other comprehensive income before reclassifications 1,014 22,321 23,335 Tax effect (37 ) - (37 ) Net current period other comprehensive income 977 22,321 23,298 Balance as of September 30, 2024 $ (504 ) $ (20,692 ) $ (21,196 )

Note 16 - Dividends and Divid_2

Note 16 - Dividends and Dividend Equivalents (Tables)	9 Months Ended
	Sep. 30, 2024
Notes Tables
Dividends Declared [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Dividend declared per share $ 1.25 $ 1.00 $ 3.75 $ 3.00 Total amount $ 60,974 $ 47,832 $ 182,680 $ 142,692

Note 2 - Revenue Recognition (D

Note 2 - Revenue Recognition (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Contract with Customer, Liability, Current	$ 6,315		$ 6,315		$ 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	$ 6,300		$ 6,300		$ 2,800
Product Concentration Risk [Member] | Revenue Benchmark [Member] | Product [Member]
Concentration Risk, Percentage	99%	99%	99%	99%
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Product Sales Through Distribution Arrangements [Member]
Concentration Risk, Percentage	88%	77%	87%	79%

Note 3 - Stock-based Compensa_3

Note 3 - Stock-based Compensation (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended		6 Months Ended	9 Months Ended
	Jun. 11, 2020	Feb. 29, 2024	Sep. 30, 2024	Sep. 30, 2023	Jun. 30, 2024	Sep. 30, 2024	Sep. 30, 2023	Aug. 16, 2023	Nov. 13, 2014
Share Price (in dollars per share)		$ 632.98	$ 924.5			$ 924.5
Proceeds from Stock Plans						$ 8,727	$ 7,568
Restricted Stock Units (RSUs) [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested			$ 65,700	$ 148,900		494,400	$ 388,600
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding			1,600,000			1,600,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount			$ 299,600			$ 299,600
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)						31,000
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)						31,000
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%
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%
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%
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%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Minimum Percentage Allowed		200%
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%
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			$ 1,400			$ 1,400
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares)			7,000	9,000		18,000	18,000
Employee Stock Purchase Plan Shares Issued, Intrinsic Value			$ 2,000	$ 700		$ 5,400	$ 1,400
Proceeds from Stock Plans						$ 8,700	$ 7,600

Note 3 - Stock-based Compensa_4

Note 3 - Stock-based Compensation - Stock-based Compensation Plan Expenses (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share based compensation expense		$ 51,398	$ 33,602	$ 149,630	$ 108,603
Tax benefit related to stock-based compensation	[1]	766	667	2,272	1,753
Cost of Sales [Member]
Share based compensation expense		1,576	1,020	4,585	3,317
Research and Development Expense [Member]
Share based compensation expense		11,331	8,479	33,460	26,406
Selling, General and Administrative Expenses [Member]
Share based compensation expense		$ 38,491	$ 24,103	$ 111,585	$ 78,880
[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.

Note 3 - Stock-based Compensa_5

Note 3 - Stock-based Compensation - RSU Summary (Details) shares in Thousands	9 Months Ended
	Sep. 30, 2024 $ / shares shares
Time-Based RSUs [Member]
Balance (in shares) | shares	102
Outstanding, weighted average (in dollars per share) | $ / shares	$ 411.11
Granted (in shares) | shares	31
Granted, weighted average (in dollars per share) | $ / shares	$ 643.98
Vested (in shares) | shares	(39)
Vested, weighted average (in dollars per share) | $ / shares	$ 374.15
Forfeited (in shares) | shares	(4)
Forfeited, weighted average (in dollars per share) | $ / shares	$ 471.15
Balance (in shares) | shares	90
Outstanding, weighted average (in dollars per share) | $ / shares	$ 505.64
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	(150)
Vested, weighted average (in dollars per share) | $ / shares	$ 272.21
Forfeited (in shares) | shares	(1)
Forfeited, weighted average (in dollars per share) | $ / shares	$ 400.96
Balance (in shares) | shares	675
Outstanding, weighted average (in dollars per share) | $ / shares	$ 525.43
MSUs [Member]
Balance (in shares) | shares	1,502
Outstanding, weighted average (in dollars per share) | $ / shares	$ 152.89
Granted (in shares) | shares	0
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	$ 203.32
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	375
Granted, weighted average (in dollars per share) | $ / shares	$ 597.56
Vested (in shares) | shares	(752)
Vested, weighted average (in dollars per share) | $ / shares	$ 125.04
Forfeited (in shares) | shares	(6)
Forfeited, weighted average (in dollars per share) | $ / shares	$ 419.22
Balance (in shares) | shares	1,703
Outstanding, weighted average (in dollars per share) | $ / shares	$ 346.88
[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 4 - Acquisition (Details T

Note 4 - Acquisition (Details Textual) - Axign [Member] - USD ($) $ in Millions	Jan. 03, 2024	Sep. 30, 2024
Business Acquisition, Percentage of Voting Interests Acquired	100%
Business Combination, Consideration Transferred	$ 33.4
Payment to Acquire Business Held in Escrow	$ 3.8
Business Acquisition, Transaction Costs		$ 0.4

Note 4 - Acquisitions - Prelimi

Note 4 - Acquisitions - Preliminary Purchase Price Allocation (Details) - USD ($) $ in Thousands	Sep. 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 Compon_3

Note 5 - Balance Sheet Components (Details Textual) - USD ($) $ in Thousands		Sep. 30, 2024	Dec. 31, 2023
Prepaid Wafer Purchase, Current		$ 60,000
Other Receivables, Net, Current	[1]	$ 0	$ 50,000
[1]The Company held $60 million in prepaid wafer purchases as of September 30, 2024 related to deposits made to a supplier under a long-term wafer supply agreement. The Company held $50 million in other receivables as of December 31, 2023 associated with those deposits. See Note 9 for details about the supply agreement.

Note 5 - Balance Sheet Compon_4

Note 5 - Balance Sheet Components - Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Raw materials	$ 70,567	$ 118,917
Work in process	182,312	112,750
Finished goods	172,063	152,035
Total	$ 424,942	$ 383,702

Note 5 - Balance Sheet Compon_5

Note 5 - Balance Sheet Components - Other Current Assets (Details) - USD ($) $ in Thousands		Sep. 30, 2024	Dec. 31, 2023
Prepaid wafer purchases	[1]	$ 60,000	$ 0
Prepaid expenses		31,379	28,964
RSU tax withholding proceeds receivable		54	20,141
Other receivables	[1]	0	50,000
Restricted cash	[2],[3]	0	33,204
Other		17,021	15,154
Total		$ 108,454	$ 147,463
[1]The Company held $60 million in prepaid wafer purchases as of September 30, 2024 related to deposits made to a supplier under a long-term wafer supply agreement. The Company held $50 million in other receivables as of December 31, 2023 associated with those deposits. See Note 9 for details about the supply agreement.[2]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.[3]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.

Note 5 - Balance Sheet Compon_6

Note 5 - Balance Sheet Components - Other Long-term Assets (Details) - USD ($) $ in Thousands		Sep. 30, 2024	Dec. 31, 2023
Deferred compensation plan assets		$ 89,324	$ 78,381
Prepaid wafer purchases	[1]	60,000	120,000
Operating lease right-of-use (“ROU”) and related assets	[2]	35,026	8,355
Other		6,673	4,541
Total		$ 191,023	$ 211,277
[1]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.[2]The operating lease ROU and related assets as of September 30, 2024 includes a fair value measurement related to favorable market terms on a building lease.

Note 5 - Balance Sheet Compon_7

Note 5 - Balance Sheet Components - Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Dividends and dividend equivalents	$ 62,564	$ 57,697
Stock rotation and sales returns	24,033	18,843
Warranty	14,344	16,906
Customer prepayments	6,315	2,792
Income tax payable	11,407	8,063
Other	20,768	11,490
Total	$ 139,431	$ 115,791

Note 5 - Balance Sheet Compon_8

Note 5 - Balance Sheet Components - Other Long-term Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Deferred compensation plan liabilities	$ 84,128	$ 80,903
Operating lease liabilities	13,482	5,565
Dividend equivalents	4,196	2,187
Total	$ 101,806	$ 88,655

Note 6 - Leases (Details Textua

Note 6 - Leases (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Lessee, Operating Lease, Lease Not yet Commenced, Future Lease Obligations	$ 0		$ 0
Operating Lease, Lease Income, Lease Payments	$ 300	$ 400	$ 700	$ 1,200
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

Note 6 - Leases - Balance Sheet Information (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Operating lease ROU assets	$ 17,522	$ 8,355
Operating lease liabilities, current	2,814	2,303
Operating lease liabilities, noncurrent	$ 13,482	$ 5,565

Note 6 - Leases - Balance She_2

Note 6 - Leases - Balance Sheet Information (Details) (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Assets [Abstract]
Other Assets, Noncurrent	$ 191,023	$ 211,277
Liabilities, Current [Abstract]
Accrued Liabilities, Current	139,431	115,791
Liabilities, Noncurrent [Abstract]
Other Liabilities, Noncurrent	$ 101,806	$ 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 (D

Note 6 - Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Operating lease costs	$ 948	$ 852	$ 2,859	$ 2,327
Other	822	480	2,020	1,572
Total lease costs	1,770	1,332	4,879	3,899
Operating cash flows for operating leases	1,704	629	3,404	2,267
ROU assets obtained in exchange for new operating lease liabilities	$ 2,339	$ 2,086	$ 11,610	$ 6,921
Weighted-average remaining lease term (in years) (Year)	11 years 3 months 18 days		11 years 3 months 18 days		4 years 8 months 12 days
Weighted-average discount rate	5.40%		5.40%		4.30%

Note 6 - Leases - Maturities of

Note 6 - Leases - Maturities of Lease Liabilities (Details) $ in Thousands	Sep. 30, 2024 USD ($)
2024 (remaining three months)	$ 958
2025	3,326
2026	2,787
2027	2,298
2028	1,550
Thereafter	12,639
Total remaining lease payments	23,558
Less: imputed interest	(7,262)
Total lease liabilities	$ 16,296

Note 6 - Leases - Maturities _2

Note 6 - Leases - Maturities of Income Related to Lease Payments (Details) $ in Thousands	Sep. 30, 2024 USD ($)
2024 (remaining three months)	$ 264
2025	583
2026	403
2027	373
2028	384
Thereafter	129
Total	$ 2,136

Note 7 - Net Income Per Share_2

Note 7 - Net Income Per Share (Details Textual) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2024	Oct. 31, 2023
Stock Repurchased and Retired During Period, Shares (in shares)	6,000	19,000
Stock Repurchased and Retired During Period, Value	$ 5,534	$ 14,160
Maximum [Member]
Share Repurchase Program, Authorized, Amount			$ 640,000

Note 7 - Net Income Per Share -

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		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Net income	$ 144,430	$ 121,163	$ 337,337	$ 330,469
Weighted-average outstanding shares — basic (in shares)	48,757	47,780	48,692	47,501
Effect of dilutive securities (in shares)	207	1,012	253	1,233
Weighted-average outstanding shares — diluted (in shares)	48,964	48,792	48,945	48,734
Earnings per share, basic (in dollars per share)	$ 2.96	$ 2.54	$ 6.93	$ 6.96
Earnings per share, diluted (in dollars per share)	$ 2.95	$ 2.48	$ 6.89	$ 6.78

Note 8 - Segment, Significant_3

Note 8 - Segment, Significant Customers and Geographic Information (Details Textual)	9 Months Ended
	Sep. 30, 2024
Number of Reportable Segments	1

Note 8 - Segment, Significant_4

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		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Accounts Receivable [Member] | Distributor A [Member]
Concentration risk			25%		42%
Accounts Receivable [Member] | Distributor B [Member]
Concentration risk			25%		13%
Accounts Receivable [Member] | Distributor C [Member]
Concentration risk			10%		10%
Revenue Benchmark [Member] | Distributor A [Member]
Concentration risk	24%	27%	33%	23%
Revenue Benchmark [Member] | Distributor B [Member]
Concentration risk	25%	21%	19%	21%
Revenue Benchmark [Member] | Distributor C [Member]
Concentration risk				10%

Note 8 - Segment, Significant_5

Note 8 - Segment, Significant Customers and Geographic Information - Revenue By Region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Revenue	$ 620,119	$ 474,867	$ 1,585,435	$ 1,367,060
CHINA
Revenue	310,472	234,924	856,026	676,148
TAIWAN
Revenue	179,747	103,537	407,593	222,582
KOREA, REPUBLIC OF
Revenue	51,815	41,698	126,865	128,047
Europe [Member]
Revenue	25,145	29,827	61,992	109,278
UNITED STATES
Revenue	13,797	23,565	42,544	82,153
South East Asia [Member]
Revenue	22,772	22,538	47,363	70,678
JAPAN
Revenue	16,286	18,605	42,786	77,708
Other Region [Member]
Revenue	$ 85	$ 173	$ 266	$ 466

Note 8 - Segment, Significant_6

Note 8 - Segment, Significant Customers and Geographic Information - Revenue By Product Family (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Revenue	$ 620,119	$ 474,867	$ 1,585,435	$ 1,367,060
DC To DC Products [Member]
Revenue	616,105	447,394	1,563,472	1,290,750
Lighting Control Products [Member]
Revenue	$ 4,014	$ 27,473	$ 21,963	$ 76,310

Note 8 - Segment, Significant_7

Note 8 - Segment, Significant Customers and Geographic Information - Long Lived Assets By Geographic Region (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Long lived assets by region	$ 436,265	$ 368,952
CHINA
Long lived assets by region	237,113	184,685
UNITED STATES
Long lived assets by region	125,952	119,430
TAIWAN
Long lived assets by region	39,929	39,419
Other Region [Member]
Long lived assets by region	$ 33,271	$ 25,418

Note 9 - Commitments and Cont_3

Note 9 - Commitments and Contingencies (Details Textual) $ in Thousands	Sep. 30, 2024 USD ($)
Purchase Obligation	$ 586,870
Prepaid Wafer Purchase, Current	60,000
Long-term Supply Agreement [Member]
Purchase Obligation	$ 120,000
Minimum [Member]
Product Warranty Obligation, Term (Year)	1 year
Maximum [Member]
Product Warranty Obligation, Term (Year)	2 years

Note 9 - Commitments and Cont_4

Note 9 - Commitments and Contingencies - Changes in Warranty Reserve (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Balance	$ 14,702	$ 17,654	$ 16,906	$ 24,082
Warranties issued	570	1,858	2,895	2,800
Repairs, replacement and refund	(849)	(367)	(4,979)	(2,619)
Changes in liability for pre-existing warranties	(79)	(2,102)	(478)	(7,220)
Balance	$ 14,344	$ 17,043	$ 14,344	$ 17,043

Note 9 - Commitments and Cont_5

Note 9 - Commitments and Contingencies - Estimated Future Unconditional Purchase Commitments (Details) $ in Thousands	Sep. 30, 2024 USD ($)
2024 (remaining three months)	$ 36,496
2025	518,513
2026	1,613
2027	30,248
Total	$ 586,870

Note 10 - Cash, Cash Equivale_3

Note 10 - Cash, Cash Equivalents, Investments and Restricted Cash - Cash, Cash Equivalents, Short-term and Long-term Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Cash	$ 413,010	$ 392,329
Money market funds	282,883	135,514
Certificates of deposit	171,065	127,123
U.S. treasuries and government agency bonds	581,156	358,409
Total	1,462,523	1,109,043
Cash and cash equivalents	700,347	527,843
Short-term investments	762,003	580,633
Investment within other long-term assets	173	567
Corporate Debt Securities [Member]
Available-for-sale securities	14,236	95,101
Auction Rate Securities [Member]
Available-for-sale securities	$ 173	$ 567

Note 10 - Cash, Cash Equivale_4

Note 10 - Cash, Cash Equivalents, Investments and Restricted Cash - Investment Maturity Classification (Details) $ in Thousands	Sep. 30, 2024 USD ($)
Due in less than 1 year, Amortized cost	$ 765,440
Due in less than 1 year, fair value	765,683
Due in 1 - 5 years, Amortized cost	805
Due in 1 - 5 years, fair value	774
Due in greater than 5 years, Amortized cost	175
Due in greater than 5 years, fair value	173
Total, Amortized cost	766,420
Total, fair value	$ 766,630

Note 10 - Cash, Cash Equivale_5

Note 10 - Cash, Cash Equivalents, Investments and Restricted Cash - Unrealized Gains and Losses on Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Amortized Cost	$ 1,049,303	$ 718,024
Unrealized Gains	515	331
Unrealized Losses	(305)	(1,641)
Total Fair Value	1,049,513	716,714
Money Market Funds [Member]
Amortized Cost	282,883	135,514
Unrealized Gains	0	0
Unrealized Losses	0	0
Total Fair Value	282,883	135,514
Certificates of Deposit [Member]
Amortized Cost	171,065	127,123
Unrealized Gains	0	0
Unrealized Losses	0	0
Total Fair Value	171,065	127,123
Corporate Debt Securities [Member]
Amortized Cost	14,522	96,636
Unrealized Gains	0	4
Unrealized Losses	(286)	(1,539)
Total Fair Value	14,236	95,101
US Government Agencies Short-Term Debt Securities [Member]
Amortized Cost	580,658	358,177
Unrealized Gains	515	327
Unrealized Losses	(17)	(95)
Total Fair Value	581,156	358,409
Auction Rate Securities [Member]
Amortized Cost	175	574
Unrealized Gains	0	0
Unrealized Losses	(2)	(7)
Total Fair Value	$ 173	$ 567

Note 10 - Cash, Cash Equivale_6

Note 10 - Cash, Cash Equivalents, Investments and Restricted Cash - Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Continuous Unrealized Loss Position, Less than 12 Months	$ 45,331	$ 118,391
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(15)	(114)
Continuous Unrealized Loss Position, 12 Months or Longer	19,292	71,373
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(290)	(1,527)
Unrealized Loss Position, Total	64,623	189,764
Unrealized Loss Position, Accumulated Loss, Total	(305)	(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	14,236	70,806
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(286)	(1,520)
Unrealized Loss Position, Total	14,236	91,598
Unrealized Loss Position, Accumulated Loss, Total	(286)	(1,539)
US Treasury and Government Short-Term Debt Securities [Member]
Continuous Unrealized Loss Position, Less than 12 Months	45,331
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(15)
Continuous Unrealized Loss Position, 12 Months or Longer	4,883
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(2)
Unrealized Loss Position, Total	50,214
Unrealized Loss Position, Accumulated Loss, Total	(17)
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	173	567
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(2)	(7)
Unrealized Loss Position, Total	173	567
Unrealized Loss Position, Accumulated Loss, Total	$ (2)	$ (7)

Note 10 - Cash, Cash Equivale_7

Note 10 - Cash, Cash Equivalents, Investments and Restricted Cash - Restricted Cash (Details) - USD ($) $ in Thousands		Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022
Cash and cash equivalents		$ 700,347	$ 527,843
Restricted cash	[1],[2]	0	33,204
Restricted cash included in other long-term assets	[3]	134	134
Total cash, cash equivalents and restricted cash reported on the Condensed Consolidated Statements of Cash Flows		$ 700,481	$ 561,181	$ 421,300	$ 288,729
[1]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.[2]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.[3]The restricted cash included in other long-term assets as of September 30, 2024 and December 31, 2023 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.

Note 11 - Fair Value Measurem_3

Note 11 - Fair Value Measurements - Financial Assets and Liabilities, Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Total Fair Value	$ 1,049,513	$ 716,714
Assets, fair value	1,111,150	771,550
Fair Value, Inputs, Level 1 [Member]
Assets, fair value	344,520	190,350
Fair Value, Inputs, Level 2 [Member]
Assets, fair value	766,457	580,633
Fair Value, Inputs, Level 3 [Member]
Assets, fair value	173	567
Money Market Funds [Member]
Total Fair Value	282,883	135,514
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Total Fair Value	282,883	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	171,065	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	171,065	127,123
Certificates of Deposit [Member] | Fair Value, Inputs, Level 3 [Member]
Total Fair Value	0	0
Corporate Debt Securities [Member]
Total Fair Value	14,236	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	14,236	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	581,156	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	581,156	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	173	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	173	567
Mutual Fund [Member]
Total Fair Value	61,637	54,836
Mutual Fund [Member] | Fair Value, Inputs, Level 1 [Member]
Total Fair Value	61,637	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 Compensati_3

Note 12 - Deferred Compensation Plan - Summary of Deferred Compensation Plan (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Deferred compensation plan assets	$ 89,324	$ 78,381
Deferred compensation plan liabilities	92,140	81,287
Other Long-term Assets [Member]
Deferred compensation plan assets	89,324	78,381
Accrued Compensation and Related Benefits [Member]
Deferred compensation plan liabilities	8,012	384
Other Long-term Liabilities [Member]
Deferred compensation plan liabilities	84,128	80,903
Cash Surrender Value [Member]
Deferred compensation plan assets	27,687	23,545
Mutual Funds and Money Market Funds, Fair Value [Member]
Deferred compensation plan assets	$ 61,637	$ 54,836

Note 13 - Other Income, Net - I

Note 13 - Other Income, Net - Interest and Other Income Components (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Interest income	$ 6,805	$ 6,071	$ 20,349	$ 16,844
Amortization of discount on available-for-sale securities	6,644	1,647	16,684	1,591
Gain (loss) on deferred compensation plan investments	3,894	(1,611)	9,180	3,411
Charitable contributions	(6,400)	(3,850)	(18,550)	(9,650)
Other	(665)	32	(333)	1,933
Total	$ 10,278	$ 2,289	$ 27,330	$ 14,129

Note 14 - Income Taxes (Details

Note 14 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Tax Expense (Benefit)	$ 29,876	$ 16,692	$ 66,044	$ 55,827
Effective Income Tax Rate Reconciliation, Percent	17.10%	12.10%	16.40%	14.50%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			21%	21%

Note 15 - Accumulated Other C_3

Note 15 - Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024
Balance	$ 2,195,858		$ 2,049,939
Balance	2,351,690	$ 2,195,858
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Balance	(1,481)	(1,849)	(2,184)
Other comprehensive income (loss) before reclassifications	1,014	355	87
Tax effect	(37)	(50)	248
Other comprehensive loss, net of tax	977	368	335
Amounts reclassified from accumulated other comprehensive loss		63
Balance	(504)	(1,481)	(1,849)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance	(43,013)	(38,700)	(24,878)
Other comprehensive income (loss) before reclassifications	22,321	(4,313)	(13,822)
Tax effect	0	0	0
Other comprehensive loss, net of tax	22,321	(4,313)	(13,822)
Amounts reclassified from accumulated other comprehensive loss		0
Balance	(20,692)	(43,013)	(38,700)
AOCI Attributable to Parent [Member]
Balance	(44,494)	(40,549)	(27,062)
Other comprehensive income (loss) before reclassifications	23,335	(3,958)	(13,735)
Tax effect	(37)	(50)	248
Other comprehensive loss, net of tax	23,298	(3,945)	(13,487)
Amounts reclassified from accumulated other comprehensive loss		63
Balance	$ (21,196)	$ (44,494)	$ (40,549)

Note 16 - Dividends and Divid_3

Note 16 - Dividends and Dividend Equivalents (Details Textual) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Dividends Payable, Current	$ 61	$ 47.9
Accrued Dividend Equivalents	$ 5.8	$ 11.9

Note 16 - Dividends and Divid_4

Note 16 - Dividends and Dividend Equivalents - Cash Dividends (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Dividend declared per share (in dollars per share)	$ 1.25	$ 1	$ 3.75	$ 3
Total amount	$ 60,974	$ 47,832	$ 182,680	$ 142,692