Note 4 - Stock-based Compensation (Tables)

9 Months Ended

Dec. 31, 2022

Notes Tables

Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Three Months Ended December 31,				Nine Months Ended December 31,
	2022		2021		2022		2021
Cost of revenues	$	89	$	36	$	195	$	148
Research and development		214		190		570		629
Selling, general and administrative		1,137		894		2,727		2,736
Total	$	1,440	$	1,120	$	3,492	$	3,513

Disclosure of Share-Based Compensation Arrangements by Share-Based Payment Award [Table Text Block]

	Three Months Ended December 31,				Nine Months Ended December 31,
	2022		2021		2022			2021
Expected volatility		N/A		N/A		71.40	%		N/A
Risk-free interest rate		N/A		N/A		3.10	%		N/A
Expected life (years)		N/A		N/A		6.14			N/A
Dividend yield		N/A		N/A		None			N/A