Condensed Statement of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities
Net loss	$ (16,719)	$ (11,400)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	837	598
Loss on disposal of property and equipment		80
Stock-based compensation	1,511	520
Non-cash loss on extinguishment of debt	185
Change in fair value of redeemable convertible preferred stock warrant liability		(32)
Change in fair value of derivative liability		(798)
Non-cash interest expense	188	1,066
Compensation expense related to vesting of common stock to GLOBALFOUNDRIES	1,224	751
Changes in operating assets and liabilities:
Accounts receivable	(530)	(417)
Amounts due from related parties	3	(55)
Inventory	320	(277)
Prepaid expenses and other current assets	(2,628)	(1,127)
Other assets	(11)	(21)
Accounts payable	574	598
Accrued liabilities	279	204
Amounts due to related parties	(77)	2,959
Deferred income on shipments to distributors	323	206
Deferred revenue		(187)
Net cash used in operating activities	(14,521)	(7,332)
Cash flows from investing activities
Purchases of property and equipment	(2,170)	(596)
Net cash used in investing activities	(2,170)	(596)
Cash flows from financing activities
Proceeds from convertible promissory notes-related party		8,500
Proceeds from debt	12,000	1,500
Payments on debt	(8,356)	(598)
Payments of debt issuance costs	(49)	(40)
Payments on capital lease obligation	(7)	(179)
Payments of deferred offering costs		(1,611)
Proceeds from exercise of stock options and purchase of shares in employee stock purchase plan	1,218	48
Net cash provided by financing activities	4,806	7,620
Net decrease in cash and cash equivalents	(11,885)	(308)
Cash and cash equivalents at beginning of period	29,727	2,307
Cash and cash equivalents at end of period	17,842	1,999
Supplementary cash flow information:
Interest paid	396	916
Non-cash investing and financing activities:
Purchase of property and equipment in accounts payable and amounts due to related parties	$ 764
Purchase of property and equipment under capital lease obligations		34
Deferred offering costs recorded in accounts payable and accrued liabilities		$ 1,490