2. REVENUE RECOGNITION - Revenue disaggregated (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Net revenues	$ 6,763	$ 10,049	$ 20,043	$ 34,808
Contract Manufacturers
Disaggregation of Revenue [Line Items]
Net revenues	3,154	3,022	9,007	11,745
Distribution
Disaggregation of Revenue [Line Items]
Net revenues	3,586	6,603	10,692	21,346
OEMs
Disaggregation of Revenue [Line Items]
Net revenues	$ 23	$ 424	$ 344	$ 1,717

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration