Stock-Based Compensation (Tables)

6 Months Ended

Jul. 01, 2018

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of stock based compensation expense

The stock-based compensation expense included in the Company's consolidated financial statements for the three and six-months ended July 1, 2018 and July 2, 2017 was as follows (in thousands):

	Three Months Ended				Six Months Ended
	July 1, 2018		July 2, 2017		July 1, 2018		July 2, 2017
Cost of revenue	$	35	$	20	$	69	$	53
Research and development		207		134		390		273
Selling, general and administrative		237		193		452		339
Total costs and expenses	$	479	$	347	$	911	$	665

Summary of the activity in the shares available for grant under the 2009 plan

The following table summarizes the activity in the shares available for grant under the 2009 Plan during the six months ended July 1, 2018:

	Shares Available for Grant
	(in thousands)
Balance at December 31, 2017		3,899
Authorized		4,000
RSUs granted		(1,229	)
RSUs forfeited or expired		136
Options forfeited		50
Balance at July 1, 2018		6,856

Summary of stock options outstanding and stock option activity under the 1999 plan and the 2009 plan, and the related weighted average exercise price

The following table summarizes stock options outstanding and stock option activity under the 2009 Plan, and the related weighted average exercise price, for the first six months of 2018:

	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Term		Aggregate Intrinsic Value
	(in thousands)					(in years)		(in thousands)
Balance outstanding at December 31, 2017		3,558		$	2.09
Forfeited or expired		(50	)
Balance outstanding at July 1, 2018		3,508		$	2.08		3.89	$	285
Exercisable at July 1, 2018		3,066		$	2.24		3.29	$	167
Vested and expected to vest at July 1, 2018		3,430		$	2.11		3.80	$	263

Summary of activity for RSUs and PRSUs

A summary of activity for the Company's RSUs for the six months ended July 1, 2018 and information regarding RSUs outstanding and expected to vest as of July 1, 2018 is as follows:

	RSUs & PRSUs Outstanding
	Number of Shares			Weighted Average Grant Date Fair Value
	(in thousands)
Nonvested at December 31, 2017		2,363		$	1.54
Granted		1,229			1.55
Vested		(365	)		1.39
Forfeited		(136	)		—
Nonvested at July 1, 2018		3,091		$	1.56

Summary of the fair value of rights issued pursuant to ESPP

The fair value of rights issued pursuant to the Company's 2009 ESPP was estimated on the commencement date of each offering period using the following weighted average assumptions:

	Three Months Ended						Six Months Ended
	July 1, 2018			July 2, 2017			July 1, 2018			July 2, 2017
Expected term (months)		6.00			6.0			6.00			6.00
Risk-free interest rate		2.09	%		1.02	%		2.09	%		1.02	%
Volatility		44.76	%		49.71	%		44.76	%		49.71	%
Dividend yield		—			—			—			—