7. STOCK- BASED COMPENSATION (Tables)

9 Months Ended

Dec. 31, 2015

Stock-Based Compensation

Summary of stock option activities

			Weighted
		Number of Shares	Average	Weighted
	Shares	Underlying	Remaining	Average
	Available for	Options	Contractual	Exercise		Intrinsic
	Grant	Outstanding	Life (Years)	Price		Value
Balance at March 31, 2015	6,213,943	6,774,151		$	5.16
Options reserved	1,156,419	—			—
Granted	(661,103)	661,103			4.90
Exercised	—	(76,745)			4.19	$	46,977
Forfeited/expired	9,864	(19,864)			4.64
Balance at December 31, 2015	6,719,123	7,338,645		$	5.15
Options vested and exercisable		4,976,550	3.82	$	5.05	$	484,583
Options vested and expected to vest		7,290,669	5.22	$	5.14	$	484,583

Schedule of options outstanding by exercise price

				Number of	Options Outstanding			Options Exercisable
				Shares	Weighted		Weighted Average		Weighted
				Underlying	Average		Remaining	Number	Average
				Options	Exercise		Contractual	Vested and	Exercise
Exercise Price				Outstanding	Price		Life (Years)	Exercisable	Price
$	2.43	-	3.43	892,584	$	3.18	3.10	892,584	$	3.18
$	3.75	-	4.00	812,779	$	3.96	3.21	812,779	$	3.96
$	4.17	-	4.68	747,515	$	4.30	5.94	357,926	$	4.30
$	4.81	-	4.98	997,676	$	4.92	7.88	389,871	$	4.88
$	5.13	-	5.34	625,513	$	5.23	8.74	49,980	$	5.19
$	5.50			783,433	$	5.50	0.88	783,433	$	5.50
$	5.59	-	6.00	901,930	$	5.77	5.53	532,248	$	5.81
$	6.28	-	6.63	812,219	$	6.48	6.36	645,440	$	6.47
$	6.82	-	7.00	651,376	$	6.90	6.06	398,669	$	6.92
$	9.20			113,620	$	9.20	5.07	113,620	$	9.20
				7,338,645	$	5.15	5.25	4,976,550	$	5.05

Summary of stock-based compensation expense by line item

	Three Months Ended December 31,				Nine Months Ended December 31,
	2015		2014		2015		2014
	(In thousands)
Cost of revenues	$	85	$	93	$	242	$	296
Research and development		208		220		649		709
Selling, general and administrative		121		77		496		528
Total	$	414	$	390	$	1,387	$	1,533

Schedule of weighted average assumptions

	Three Months Ended December 31,						Nine Months Ended December 31,
	2015			2014			2015				2014
	(In thousands)						(In thousands)
Stock Option Plans:
Risk-free interest rate		1.56	%		1.60	%	1.52	-	1.57	%	1.60	-	1.70	%
Expected life (in years)		5.00			5.00		5.00						5.00
Volatility		36.3	%		41.3	%	36.3	-	38.0	%	41.3	-	44.8	%
Dividend yield		—	%		—	%	—		—	%			—	%
Employee Stock Purchase Plan:
Risk-free interest rate		0.15	%		0.05	%	0.09	-	0.15	%			0.05	%
Expected life (in years)		0.50			0.50		0.50						0.50
Volatility		27.9	%		38.0	%	26.3	-	27.9	%	30.8	-	38.0	%
Dividend yield		—	%		—	%			—	%			—	%