CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Income Statement [Abstract]
Net sales	$ 56,016	$ 53,296
Cost and expenses:
Cost of sales	40,432	37,757
Research and development	13,460	8,370
Selling, general and administrative	15,053	10,876
Total cost and expenses	68,945	57,003
Loss from operations	(12,929)	(3,707)
Interest and other, net	10	92
Loss before income taxes	(12,919)	(3,615)
Income tax benefit	(816)	(391)
Net loss	$ (12,103)	$ (3,224)
Loss per share:
Basic	$ (0.49)	$ (0.13)
Diluted	$ (0.49)	$ (0.13)
Weighted average shares used in computing loss per share:
Basic	24,657	24,353
Diluted	24,657	24,353
Cash dividends declared per share	$ 0.06	$ 0.06