GEOGRAPHIC AND CUSTOMER CONCENTRATION INFORMATION - Summary of Net Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	$ 38,894	$ 38,430	$ 140,482	$ 123,657
Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	99.50%	100.00%	100.00%	100.00%
Reportable Geographical Components | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	$ 2,935	$ 8,188	$ 14,509	$ 18,763
Reportable Geographical Components | United States | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	7.00%	21.00%	10.00%	15.00%
Reportable Geographical Components | South Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	$ 6,699	$ 15,613	$ 67,439	$ 49,735
Reportable Geographical Components | South Korea | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	17.00%	41.00%	48.00%	40.00%
Reportable Geographical Components | China
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	$ 15,893	$ 853	$ 24,607	$ 16,202
Reportable Geographical Components | China | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	41.00%	2.00%	18.00%	13.00%
Reportable Geographical Components | Taiwan
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	$ 6,855	$ 10,746	$ 14,894	$ 27,066
Reportable Geographical Components | Taiwan | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	18.00%	28.00%	11.00%	22.00%
Reportable Geographical Components | Other Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	$ 4,273	$ 1,718	$ 14,503	$ 5,588
Reportable Geographical Components | Other Asia | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	11.00%	5.00%	10.00%	5.00%
Reportable Geographical Components | Europe and others
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	$ 2,239	$ 1,312	$ 4,530	$ 6,303
Reportable Geographical Components | Europe and others | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	6.00%	3.00%	3.00%	5.00%