CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net revenue
Total net revenue	$ 3,066	$ 4,598	$ 6,586	$ 8,806
Cost of net revenue	1,228	1,833	2,582	3,434
Gross profit	1,838	2,765	4,004	5,372
Operating expenses
Research and development	981	990	2,134	2,041
Selling, general and administrative	932	1,250	1,904	2,239
Total operating expenses	1,913	2,240	4,038	4,280
Income (loss) from operations	(75)	525	(34)	1,092
Interest expense	(56)	(206)	(110)	(427)
Other income (expense), net	28	(3)	51
Income (loss) before income tax provision	(103)	316	(93)	665
Income tax provision		1		2
Net income (loss)	(103)	315	(93)	663
Other comprehensive income, net of tax:
Net unrealized gains on available-for-sale securities	1		1
Comprehensive income (loss)	$ (102)	$ 315	$ (92)	$ 663
Net income (loss) per share
Basic	$ 0.00	$ 0.04	$ 0.00	$ 0.08
Diluted	$ 0.00	$ 0.04	$ 0.00	$ 0.08
Shares used in computing net income (loss) per share
Basic	43,171	8,171	43,115	8,151
Diluted	43,171	8,409	43,115	8,378
Product [Member]
Net revenue
Total net revenue	$ 2,810	$ 4,051	$ 6,196	$ 7,755
Royalty And Other [Member]
Net revenue
Total net revenue	$ 256	$ 547	$ 390	$ 1,051