Condensed Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013
Income Statement [Abstract]
Net revenue	$ 47,060	$ 52,365	$ 88,378	$ 98,990
Cost of net revenue	28,987	31,646	55,562	58,454
Gross profit	18,073	20,719	32,816	40,536
Operating expense:
Research and development	9,095	10,476	20,479	20,640
Selling, general and administrative	14,902	10,557	28,263	21,277
Total operating expense	23,997	21,033	48,742	41,917
Loss from operations	(5,924)	(314)	(15,926)	(1,381)
Interest income (expense), net	33	(59)	68	(138)
Other income (expense), net	44	(15)	63	(49)
Loss before income taxes	(5,847)	(388)	(15,795)	(1,568)
Income tax expense	117	60	162	88
Net loss	$ (5,964)	$ (448)	$ (15,957)	$ (1,656)
Net income per share attributable to common stockholders:
Basic and diluted net loss per share, in dollars per share	$ (0.18)	$ (0.01)	$ (0.48)	$ (0.05)
Shares used to compute net income per share attributable to common stockholders:
Shares used to compute basic and diluted net loss per share	33,274	32,171	33,105	32,048