Note 7 - EMPLOYEE BENEFIT PLANS (Tables)

6 Months Ended

Jun. 30, 2022

Notes Tables

Schedule of Share-based Payment Awards, Stock Options, Valuation Assumptions

	2021 Purchase Plan			2010 Purchase Plan
	Six Months Ended June 30,			Six Months Ended June 30,
	2022			2021
Expected life (in years)		1.25			1.25
Volatility		48.90	%		34.25	%
Risk-free interest rate		0.86	%		1.43	%
Expected dividend		—			—
Weighted average fair value of purchase rights granted during the period	$	10.76		$	4.83

Schedule of Share-based Payment Arrangement, Expensed and Capitalized Amounts

Stock-based compensation is estimated at the grant date based on the award’s fair value and is recognized on a straight-line basis over the vesting periods, generally four years. Stock-based compensation expense before taxes related to the Company’s stock plans and employee stock purchase plans was allocated as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Costs of revenues	$	655	$	538	$	1,383	$	1,190
Research and development		1,810		1,126		4,978		2,714
Selling, general and administrative		1,407		1,078		3,064		2,207
Stock-based compensation expenses	$	3,872	$	2,742	$	9,425	$	6,111

Schedule of Share-based Payment Arrangement, Options Activity

				Weighted
		Weighted		Average
		Average		Remaining	Aggregate
	Number of	Exercise		Contractual	Intrinsic
	Options	Price		Term	Value
	(in thousands)	per Share		(Years)	(in thousands)
Outstanding, January 1, 2022	226	$	12.78
Granted	—		—
Exercised	(87)		9.10
Canceled	(4)		13.30
Expired	(2)		8.79
Outstanding, June 30, 2022	133	$	15.19	3.80	$	848
Vested and expected to vest, June 30, 2022	133	$	15.18	3.78	$	843
Exercisable, June 30, 2022	112	$	15.16	3.22	$	714

Schedule of Share-based Payment Arrangement, Restricted Stock Unit Activity

		Weighted
		Average Grant
	Shares	Date Fair Value
	(in thousands)	Per Share
Nonvested, January 1, 2022	1,872	$	18.24
Granted	331	$	27.24
Vested	(462)	$	17.94
Forfeited	(56)	$	19.38
Nonvested, June 30, 2022	1,685	$	20.05