Note 13 - Segment Information (Tables)

12 Months Ended

Dec. 31, 2012

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

	Year ended December 31,
Country	2012		2011		2010
China	$	124,278	$	113,469	$	105,233
Taiwan		27,477		23,634		25,840
South East Asia		21,641		14,789		10,219
Europe		16,201		14,416		20,416
Korea		9,434		14,183		33,761
Japan		8,516		10,681		14,255
USA		5,711		4,422		8,415
Other		555		925		701
Total	$	213,813	$	196,519	$	218,840

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

	Year ended December 31,															Percent Change
Product Family	2012		% of Revenue			2011*		% of Revenue			2010*		% of Revenue			2012 to 2011 Change			2011 to 2010 Change
DC to DC Converters	$	188,736		88.3	%	$	170,032		86.5	%	$	190,286		87.0	%		11.0	%		(10.6	%)
Lighting Control Products		25,077		11.7	%		26,487		13.5	%		28,554		13.0	%		(5.3	%)		(7.2	%)
Total	$	213,813		100.0	%	$	196,519		100.0	%	$	218,840		100.0	%		8.8	%		(10.2	%)

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

	December 31,
	2012		2011
China	$	37,071	$	32,566
United States		23,163		15,662
Taiwan		90		98
Japan		57		70
Other		55		51
TOTAL	$	60,436	$	48,447