CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Income Statement
Net revenues	$ 51,486	$ 42,643	$ 48,180
Cost of revenues	19,858	20,217	21,764
Gross profit	31,628	22,426	26,416
Operating expenses:
Research and development	21,355	16,998	15,803
Selling, general and administrative	10,455	9,899	11,140
Total operating expenses	31,810	26,897	26,943
Loss from operations	(182)	(4,471)	(527)
Interest income, net	671	421	312
Other income (expense), net	(221)	(12)	166
Income (loss) before income taxes	268	(4,062)	(49)
Provision for income taxes	105	453	66
Net income (loss)	$ 163	$ (4,515)	$ (115)
Net income (loss) per share:
Basic	$ 0.01	$ (0.21)	$ (0.01)
Diluted	$ 0.01	$ (0.21)	$ (0.01)
Weighted Average Number Of Shares Outstanding [Abstract]
Basic	21,889	21,085	20,652
Diluted	23,349	21,085	20,652