Stockholders' Equity (Tables)

12 Months Ended

Dec. 28, 2013

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Stock-Based Compensation Expense

Total stock-based compensation expense included in our Consolidated Statements of Operations was as follows (in thousands):

	Year Ended
	December 28, 2013		December 29, 2012		December 31, 2011
Line item:
Cost of products sold	$	627	$	525	$	461
Research and development	3,916		3,009		2,697
Selling, general and administrative	4,979		3,976		3,095
Restructuring charges	—		—		103
Total stock-based compensation	$	9,522	$	7,510	$	6,356

Schedule of Share-based Payment Award, Stock Options and Employee Stock Purchase Plan, Valuation Assumptions

	Year Ended
	December 28, 2013	December 29, 2012	December 31, 2011
Employee and Director Stock Options
Expected volatility (%)	51.4 to 54.3	58.1 to 59.5	57.4 to 61.9
Risk-free interest rate (%)	.007 to .01	.006 to .01	.003 to .02
Expected term (in years)	4.09 to 4.53	4.09 to 4.47	4.05 to 4.37
Dividend yield	—%	—%	—%
Employee Stock Purchase Plan
Weighted average expected volatility (%)	48.0	50.0	48.1
Weighted average risk-free interest rate (%)	0.11	0.12	0.14
Expected term (in years)	0.50	0.50	0.50
Dividend yield	—%	—%	—%

Schedule of Share-based Compensation, Stock Options, Activity

The following table summarizes our stock option activity and related information for the year ended December 28, 2013 (shares and aggregate intrinsic value in thousands):

	Shares		Weighted average exercise price		Weighted average remaining contractual term (years)	Aggregate Intrinsic Value
Balance, December 29, 2012	9,528		$	4.74
Granted	3,167		5.01
Exercised	(990	)	2.38
Forfeited or expired	(1,264	)	6.09
Balance, December 28, 2013	10,441		$	4.88
Vested and expected to vest at December 28, 2013	10,441		$	4.88	4.80	$	8,220
Exercisable, December 28, 2013	5,323		$	4.46	3.81	$	6,450

Schedule of Nonvested Restricted Stock Units Activity

The following table summarizes our RSU activity for the year ended December 28, 2013 (shares in thousands):

	Shares		Weighted average grant date fair value
Balance at December 29, 2012	1,078		$	6.15
Granted	1,735		5.22
Vested	(524	)	5.91
Forfeited	(99	)	5.68
Balance at December 28, 2013	2,190		$	5.49