Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 25, 2022	Jun. 26, 2021	Jun. 25, 2022	Jun. 26, 2021
Net sales		$ 217,226	$ 244,803	$ 414,983	$ 470,291
Cost and expenses:
Cost of sales (1)	[1]	116,273	140,146	222,874	263,429
Research and development		23,160	23,423	46,266	46,575
Selling, general and administrative		32,531	32,834	63,777	65,458
Amortization of purchased intangible assets		8,341	9,045	16,876	18,289
Restructuring charges		7	617	583	1,957
Gain on sale of PCB Test business		0	(75,779)	0	(75,664)
Costs and Expenses, Total		180,312	130,286	350,376	320,044
Income from operations		36,914	114,517	64,607	150,247
Other (expense) income:
Interest expense		(919)	(1,831)	(1,900)	(4,406)
Interest income		308	94	419	144
Foreign transaction gain (loss)		1,491	(25)	2,635	(287)
Gain (Loss) on Extinguishment of Debt, Total		(128)	0	(232)	(1,761)
Income from operations before taxes		37,666	112,755	65,529	143,937
Income tax provision		8,898	17,659	15,192	21,234
Net income		$ 28,768	$ 95,096	$ 50,337	$ 122,703
Basic (in dollars per share)		$ 0.59	$ 1.96	$ 1.04	$ 2.66
Diluted (in dollars per share)		$ 0.59	$ 1.92	$ 1.02	$ 2.58
Weighted average shares used in computing income per share:
Basic (in shares)		48,475	48,555	48,626	46,155
Diluted (in shares)		48,928	49,474	49,248	47,478

[1] Excludes amortization of $6,544 and $7,043 for the three months ended June 25, 2022 and June 26, 2021, respectively, and $13,240 and $14,144 for the six months ended June 25, 2022 and June 26, 2021, respectively.