CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 29, 2013	Jun. 30, 2012	Jun. 29, 2013	Jun. 30, 2012
Income Statement [Abstract]
Net sales	$ 66,652	$ 59,404	$ 122,668	$ 112,700
Cost and expenses:
Cost of sales	45,179	41,740	85,611	79,497
Research and development	11,718	8,688	25,178	17,058
Selling, general and administrative	14,200	11,041	29,253	21,917
Total cost and expenses	71,097	61,469	140,042	118,472
Loss from operations	(4,445)	(2,065)	(17,374)	(5,772)
Interest and other, net	16	89	26	181
Loss before income taxes	(4,429)	(1,976)	(17,348)	(5,591)
Income tax provision (benefit)	(384)	133	(1,200)	(258)
Net loss	$ (4,045)	$ (2,109)	$ (16,148)	$ (5,333)
Loss per share:
Basic	$ (0.16)	$ (0.09)	$ (0.65)	$ (0.22)
Diluted	$ (0.16)	$ (0.09)	$ (0.65)	$ (0.22)
Weighted average shares used in computing loss per share:
Basic	24,817	24,432	24,737	24,392
Diluted	24,817	24,432	24,737	24,392
Cash dividends declared per share	$ 0.06	$ 0.06	$ 0.12	$ 0.12