Note 6 - Segment and Geographic Information (Tables)

9 Months Ended

Sep. 30, 2017

Notes Tables

Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]

	Three Months Ended September 30,						Nine Months Ended September 30,
Customer	2017			2016			2017			2016
Distributor A		17	%		22	%		17	%		22	%
Distributor B		15	%		*			*			*

Schedule of Accounts Receivable by Major Customers by Reporting Segments [Table Text Block]

	September 30,			December 31,
Customer	2017			2016
Distributor A		17	%		19	%
Distributor B		16	%		*
Distributor C		12	%		17	%

Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block]

	Three Months Ended September 30,				Nine Months Ended September 30,
Country or Region	2017		2016		2017		2016
China	$	66,645	$	67,372	$	185,054	$	180,689
Taiwan		27,387		12,786		59,548		31,801
Europe		10,726		7,193		28,227		21,232
Korea		9,279		7,405		25,594		21,522
Southeast Asia		7,179		5,370		20,476		13,210
Japan		4,813		4,084		14,584		9,771
United States		2,781		2,164		7,711		6,613
Other		129		82		305		209
Total	$	128,939	$	106,456	$	341,499	$	285,047

Revenue from External Customers by Products and Services [Table Text Block]

	Three Months Ended September 30,				Nine Months Ended September 30,
Product Family	2017		2016		2017		2016
DC to DC	$	119,089	$	95,615	$	312,700	$	256,953
Lighting Control		9,850		10,841		28,799		28,094
Total	$	128,939	$	106,456	$	341,499	$	285,047

Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country [Table Text Block]

	September 30,		December 31,
Country	2017		2016
United States	$	61,447	$	50,242
China		46,175		45,728
Taiwan		16,908		8,919
Bermuda		8,035		9,573
Other		413		571
Total	$	132,978	$	115,033