3. Balance Sheet Components

Inventories consisted of the following (in thousands):

	As of September 30,		As of December 31,
	2018		2017
Processed wafers	$	1,536	$	3,523
Work in process		6,733		10,118
Finished goods		6,736		4,828
Total inventories	$	15,005	$	18,469

Prepaid expenses and other current assets consisted of the following (in thousands):

	As of September 30,		As of December 31,
	2018		2017
Processed wafer prepayments	$	521	$	3,443
Electronic design automation tools		307		519
Other prepaid and other current assets		1,585		1,661
Total other prepaid and other current assets	$	2,413	$	5,623

Property and equipment, net consisted of the following (in thousands):

		As of September 30,			As of December 31,
	Estimated Useful Lives	2018			2017

Machinery and equipment	2-3 years	$	15,244		$	13,268
Production masks	4 years		5,401			5,401
Software and computer equipment	3 years		4,223			3,820
Leasehold improvements	Shorter of estimated life of asset or remaining lease term		1,546			539
Office furniture and fixtures	3 years		168			114
Total property and equipment			26,582			23,142
Less: accumulated depreciation and amortization			(16,159	)		(13,169	)
Property and equipment, net		$	10,423		$	9,973

Depreciation and amortization of property and equipment totaled $1.3 million and $1.0 million for the three months ended September 30, 2018 and 2017, respectively. Depreciation and amortization of property and equipment totaled $3.7 million and $2.8 million for the nine months ended September 30, 2018 and 2017, respectively.

Intangible assets, net were carried at cost, less accumulated amortization. Intangible assets were as follows (in thousands):

		As of September 30,			As of December 31,
	Estimated Useful Lives	2018			2017
IP license	7 years	$	5,416		$	5,416
Patents	10-12 years		348			348
Total intangible assets			5,764			5,764
Less: accumulated amortization			(1,814	)		(1,208	)
Intangible assets, net		$	3,950		$	4,556

Amortization of intangible assets totaled $0.2 million and $0.2 million for the three months ended September 30, 2018 and 2017, respectively. Amortization of intangible assets totaled $0.6 million and $0.6 million for the nine months ended September 30, 2018 and 2017, respectively.

Amortization expense related to amortizable intangibles in future periods as of September 30, 2018 is expected to be as follows (in thousands):

2018 (remaining)	$	202
2019		808
2020		808
2021		808
2022 and thereafter		1,324
Total	$	3,950

Accrued liabilities consisted of the following (in thousands):

	As of September 30,		As of December 31,
	2018		2017

Accrued compensation and related benefits	$	5,206	$	5,242
Customer Deposit		-		1,154
Accrued IP License		1,339		343
Accrued technical consulting and professional services		200		259
Accrued royalty, rebates and commission		278		287
Other accrued liabilities		3,695		1,932
Total accrued liabilities	$	10,718	$	9,217