CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net loss	$ (4,515)	$ (115)	$ (2,170)
Adjustments to reconcile net loss to net cash provided by operating activities:
Allowance for sales returns, doubtful accounts and other	(41)	4	(3)
Provision for excess and obsolete inventories	1,561	588	1,172
Depreciation and amortization	1,255	1,532	1,459
Stock-based compensation	2,070	1,877	1,850
Amortization of premium on investments	73	74	209
Changes in assets and liabilities:
Accounts receivable	1,111	1,125	782
Inventory	2,103	(2,625)	66
Prepaid expenses and other assets	117	103	102
Accounts payable	189	(887)	(441)
Accrued expenses and other liabilities	(1,183)	911	(2,081)
Deferred revenue	(1,675)	(534)	(485)
Net cash provided by operating activities	1,065	2,053	460
Cash flows from investing activities:
Purchase of investments	(13,243)	(18,563)	(14,149)
Maturities of short-term investments	16,140	23,600	23,585
Acquisition			(4,359)
(Increase) decrease in MikaMonu escrow deposit	1,234		(2,984)
Purchases of property and equipment	(1,320)	(219)	(1,158)
Net cash provided by investing activities	2,811	4,818	935
Cash flows from financing activities:
Repurchase of common stock		(7,112)	(7,026)
Payment of MikaMonu escrow deposit	(862)
Proceeds from issuance of common stock under employee stock plans	3,491	2,014	818
Net cash provided by (used in) financing activities	2,629	(5,098)	(6,208)
Net increase (decrease) in cash and cash equivalents	6,505	1,773	(4,813)
Cash and cash equivalents at beginning of the period	33,736	31,963	36,776
Cash and cash equivalents at end of the period	40,241	33,736	31,963
Non-cash financing activities:
Purchases of property and equipment through accounts payable and accruals	105
Supplemental cash flow information:
Net cash paid for income taxes	$ 39	$ 1,339	$ 78