Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 24, 2022	Sep. 25, 2021	Sep. 24, 2022	Sep. 25, 2021
Net sales		$ 206,687	$ 225,063	$ 621,670	$ 695,354
Cost and expenses:
Cost of sales (1)	[1]	108,621	129,358	331,495	392,787
Research and development		23,372	22,792	69,638	69,367
Selling, general and administrative		32,764	30,377	96,541	95,835
Amortization of purchased intangible assets		8,206	8,879	25,082	27,168
Restructuring charges		17	31	600	1,988
Gain on sale of PCB Test business		0	(90)	0	(75,754)
Costs and Expenses, Total		172,980	191,347	523,356	511,391
Income from operations		33,707	33,716	98,314	183,963
Other (expense) income:
Interest expense		(1,028)	(966)	(2,928)	(5,372)
Interest income		1,132	53	1,551	197
Foreign transaction gain (loss)		1,344	(28)	3,979	(315)
Gain (Loss) on Extinguishment of Debt, Total		(80)	(1,650)	(312)	(3,411)
Income from operations before taxes		35,075	31,125	100,604	175,062
Income tax provision		10,193	7,392	25,385	28,626
Net income		$ 24,882	$ 23,733	$ 75,219	$ 146,436
Basic (in dollars per share)		$ 0.52	$ 0.49	$ 1.55	$ 3.12
Diluted (in dollars per share)		$ 0.51	$ 0.48	$ 1.53	$ 3.04
Weighted average shares used in computing income per share:
Basic (in shares)		47,984	48,666	48,412	46,992
Diluted (in shares)		48,526	49,457	49,008	48,137

[1] Excludes amortization of $6,433 and $6,988 for the three months ended September 24, 2022 and September 25, 2021, respectively, and $19,673 and $21,133 for the nine months ended September 24, 2022 and September 25, 2021, respectively.