Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Net sales		$ 244,803	$ 144,084	$ 470,291	$ 283,005
Cost and expenses:
Cost of sales (1)	[1]	140,146	83,127	263,429	165,964
Research and development		23,423	20,424	46,575	42,892
Selling, general and administrative		32,834	30,949	65,458	64,301
Amortization of purchased intangible assets		9,045	9,527	18,289	19,065
Restructuring charges		617	585	1,957	988
Impairment charges		0	0	0	3,949
Gain on sale of PCB Test business (2)	[2]	(75,779)	0	(75,664)	0
Costs and Expenses, Total		130,286	144,612	320,044	297,159
Income (loss) from operations		114,517	(528)	150,247	(14,154)
Other (expense) income:
Interest expense		(1,831)	(3,456)	(4,406)	(7,883)
Interest income		94	21	144	168
Foreign transaction loss		(25)	(640)	(287)	(1,044)
Loss on extinguishment of debt		0	0	(1,761)	0
Income (loss) from continuing operations before taxes		112,755	(4,603)	143,937	(22,913)
Income tax provision (benefit)		17,659	137	21,234	(855)
Income (loss) from continuing operations		95,096	(4,740)	122,703	(22,058)
Income from discontinued operations		0	0	0	42
Net income (loss)		$ 95,096	$ (4,740)	$ 122,703	$ (22,016)
Basic:
Income (loss) from continuing operations (in dollars per share)		$ 1.96	$ (0.11)	$ 2.66	$ (0.53)
Income from discontinued operations (in dollars per share)		0	0	0	0.00
Net income (loss) (in dollars per share)		1.96	(0.11)	2.66	(0.53)
Diluted:
Income (loss) from continuing operations (in dollars per share)		1.92	(0.11)	2.58	(0.53)
Income from discontinued operations (in dollars per share)		0	0	0	0.00
Net income (loss) (in dollars per share)		$ 1.92	$ (0.11)	$ 2.58	$ (0.53)
Weighted average shares used in computing income (loss) per share:
Basic (in shares)		48,555	41,844	46,155	41,673
Diluted (in shares)		49,474	41,844	47,478	41,673
Cash dividend, per share (in dollars per share)		$ 0	$ 0	$ 0	$ 0.06

[1] Excludes amortization of $7,043 and $7,256 for the three months ended June 26, 2021 and June 27, 2020, respectively, and $14,144 and $14,522 for the six months ended June 26, 2021 and June 27, 2020, respectively.

[2] On June 24, 2021 we completed the divestment of our PCB Test business. The divestment of this business did not qualify for presentation as discontinued operations and the results of the PCB Test business are included in continuing operations for all periods presented. See Note 12, “Business Divestiture and Discontinued Operations” for additional information on this transaction and financial statement presentation.