Note 7 - Segment, Significant Customers and Geographic Information (Tables)

3 Months Ended

Mar. 31, 2022

Notes Tables

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

	Three Months Ended March 31,
Customer	2022			2021
Distributor A		24	%		26	%
Distributor B		18	%		16	%
Distributor C		11	%	*

	March 31,			December 31,
	2022			2021
Distributor A		20	%		26	%
Distributor B		22	%		17	%
Value-added reseller A	*​​​​				12	%

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

	Three Months Ended March 31,
Country or Region	2022		2021
China	$	206,079	$	153,383
Taiwan		56,437		30,445
Europe		25,215		20,380
South Korea		40,373		19,287
Southeast Asia		16,889		11,497
Japan		19,155		12,049
United States		13,446		7,302
Other		120		112
Total	$	377,714	$	254,455

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

	Three Months Ended March 31,
Product Family	2022		2021
Direct Current (“DC”) to DC	$	358,849	$	241,429
Lighting Control		18,865		13,026
Total	$	377,714	$	254,455

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

	March 31,		December 31,
Country	2022		2021
China	$	220,399	$	211,973
United States		113,053		113,805
Taiwan		19,376		19,607
Other		16,546		17,577
Total	$	369,374	$	362,962