CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Net revenues	$ 33,384	$ 27,729	$ 43,343
Cost of revenues	14,847	14,512	18,000
Gross profit	18,537	13,217	25,343
Operating expenses:
Research and development	24,672	23,344	25,223
Selling, general and administrative	10,218	11,137	10,922
Total operating expenses	34,890	34,481	36,145
Loss from operations	(16,353)	(21,264)	(10,802)
Interest income, net	71	295	783
Other expense, net	(131)	(201)	(71)
Loss before income taxes	(16,413)	(21,170)	(10,090)
Provision (benefit) for income taxes	(45)	335	247
Net loss	$ (16,368)	$ (21,505)	$ (10,337)
Net loss per share:
Basic	$ (0.67)	$ (0.91)	$ (0.45)
Diluted	$ (0.67)	$ (0.91)	$ (0.45)
Weighted average shares used in per share calculations:
Basic	24,303	23,671	22,968
Diluted	24,303	23,671	22,968