GEOGRAPHIC AND CUSTOMER CONCENTRATION INFORMATION - Summary of Net Revenue by Geographic Area (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 29, 2015	Mar. 30, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	$ 58,254	$ 43,198
Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	100.30%	100.00%
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	8,568	4,183
United States | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	15.00%	10.00%
South Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	33,998	10,259
South Korea | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	58.00%	24.00%
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	3,599	13,081
China | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	6.00%	30.00%
Taiwan
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	5,520	10,822
Taiwan | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	10.00%	25.00%
Other Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	5,365	2,281
Other Asia | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	9.00%	5.00%
Europe and others
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, amount	$ 1,204	$ 2,572
Europe and others | Geographic Concentration Risk | Net Sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales, percentage	2.00%	6.00%