Note 7 - Segment and Geographic Information (Tables)

9 Months Ended

Sep. 30, 2018

Notes Tables

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

<div style="display: inline; font-family: times new roman; font-size: 10pt"><table border="0" cellpadding="0" cellspacing="0" style="; font-size: 10pt; font-family: "Times New Roman", Times, serif; text-indent: 0px; min-; min-width: 700px;"> <tr style="vertical-align: bottom;"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td colspan="14" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;"><div style="display: inline; font-weight: bold;"><div style="display: inline; font-weight: bold;">Revenue</div></div></div> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; padding-bottom: 1px;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td colspan="6" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;"><div style="display: inline; font-weight: bold;"><div style="display: inline; font-weight: bold;">Accounts Receivable</div></div></div> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; padding-bottom: 1px;"> </td> </tr> <tr style="vertical-align: bottom;"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td colspan="6" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: thin solid rgb(0, 0, 0);"> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;"><div style="display: inline; font-weight: bold;"><div style="display: inline; font-weight: bold;">Three Months Ended September 30,</div></div></div> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td colspan="6" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: thin solid rgb(0, 0, 0);"> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;"><div style="display: inline; font-weight: bold;"><div style="display: inline; font-weight: bold;">Nine Months Ended September 30,</div></div></div> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;"><div style="display: inline; font-weight: bold;"><div style="display: inline; font-weight: bold;">September 30,</div></div></div> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;"><div style="display: inline; font-weight: bold;"><div style="display: inline; font-weight: bold;">December 31,</div></div></div> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> </tr> <tr style="vertical-align: bottom;"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; width: 28%; border-bottom: thin solid rgb(0, 0, 0);"> <div style=" font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-top: 0pt; margin-bottom: 0pt; text-align: center;"><div style="display: inline; font-weight: bold;">Customer</div></div> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;"><div style="display: inline; font-weight: bold;"><div style="display: inline; font-weight: bold;">2018</div></div></div> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; padding-bottom: 1px;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;"><div style="display: inline; font-weight: bold;"><div style="display: inline; font-weight: bold;">2017</div></div></div> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; padding-bottom: 1px;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;"><div style="display: inline; font-weight: bold;"><div style="display: inline; font-weight: bold;">2018</div></div></div> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; padding-bottom: 1px;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;"><div style="display: inline; font-weight: bold;"><div style="display: inline; font-weight: bold;">2017</div></div></div> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; padding-bottom: 1px;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;"><div style="display: inline; font-weight: bold;"><div style="display: inline; font-weight: bold;">2018</div></div></div> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; padding-bottom: 1px;"> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> <div style=" font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:center;"><div style="display: inline; font-weight: bold;"><div style="display: inline; font-weight: bold;">2017</div></div></div> </td> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; padding-bottom: 1px;"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204, 238, 255);"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <div style=" font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-top: 0pt; margin-bottom: 0pt;">A (distributor)</div> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">23</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">%</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">17</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">%</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">21</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">%</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">17</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">%</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">21</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">%</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">16</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">%</td> </tr> <tr style="vertical-align: bottom; background-color: rgb(255, 255, 255);"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <div style=" font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-top: 0pt; margin-bottom: 0pt;">B (distributor)</div> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">10</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">%</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">15</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">%</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">10</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">%</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">*</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">16</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">%</td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">*</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> </tr> <tr style="vertical-align: bottom; background-color: rgb(204, 238, 255);"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <div style=" font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-top: 0pt; margin-bottom: 0pt;">C (value-added reseller)</div> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">*</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">*</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">*</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">*</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">*</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td> <td style="width: 9%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"><div style="display: inline; font-style: italic; font-weight: inherit; font-style: normal;">15</div></td> <td nowrap="nowrap" style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">%</td> </tr> </table></div>

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	2018		2017		2018		2017
China	$	91,509	$	66,645	$	245,580	$	185,054
Taiwan		20,774		27,387		55,315		59,548
Europe		12,579		10,726		36,696		28,227
Korea		11,406		9,279		30,046		25,594
Southeast Asia		11,259		7,179		28,261		20,476
Japan		6,895		4,813		18,994		14,584
United States		5,375		2,781		13,404		7,711
Other		178		129		589		305
Total	$	159,975	$	128,939	$	428,885	$	341,499

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

	Three Months Ended September 30,				Nine Months Ended September 30,
Product Family	2018		2017		2018		2017
DC to DC	$	147,727	$	119,089	$	394,492	$	312,700
Lighting Control		12,248		9,850		34,393		28,799
Total	$	159,975	$	128,939	$	428,885	$	341,499

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

	September 30,		December 31,
Country	2018		2017
China	$	92,066	$	89,472
United States		68,014		65,618
Taiwan		17,033		17,238
Bermuda		6,879		7,522
Other		810		388
Total	$	184,802	$	180,238