Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 29, 2014	Mar. 30, 2013
Income Statement [Abstract]
Net sales	$ 68,417	$ 56,016
Cost and expenses:
Cost of sales	44,616	40,432
Research and development	11,172	13,460
Selling, general and administrative	16,047	15,053
Total cost and expenses	71,835	68,945
Loss from operations	(3,418)	(12,929)
Interest and other, net	15	10
Loss before taxes	(3,403)	(12,919)
Income tax benefit	(56)	(816)
Net loss	$ (3,347)	$ (12,103)
Loss per share:
Basic	$ (0.13)	$ (0.49)
Diluted	$ (0.13)	$ (0.49)
Weighted average shares used in computing loss per share:
Basic	25,123	24,657
Diluted	25,123	24,657
Cash dividends declared per share	$ 0.06	$ 0.06