Stock-Based Compensation (Tables)

3 Months Ended

Mar. 29, 2013

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock-Based Compensation Expense

The following table summarizes stock-based compensation expense (in thousands):

	Three months ended
	March 29, 2013		March 30, 2012
Stock-based compensation in:
Cost of revenue	$	611	$	753
Research and development expense		1,203		1,655
Selling, general and administrative expense		2,085		2,259
Total stock-based compensation in operating expense		3,288		3,914
Total stock-based compensation	$	3,899	$	4,667

Valuation Assumptions for Stock Options

The Company estimated the fair value of all employee stock options using a Black-Scholes valuation model with the following weighted average assumptions:

	Three months ended
	March 29, 2013			March 30, 2012
Expected term (years)		4.70			4.70
Volatility		52	%		58	%
Risk-free interest rate		0.8	%		1.0	%
Expected dividends		0.0	%		0.0	%

Employee Stock Purchase Plan

The call option and put option were valued using the Black-Scholes option pricing model with the following assumptions:

	Three months ended
	March 29, 2013			March 30, 2012
Expected term (years)		0.49			0.50
Volatility		32	%		53	%
Risk-free interest rate		0.2	%		0.2	%
Expected dividends		0.0	%		0.0	%