Note 8 - Segment and Geographic Information (Tables)

3 Months Ended

Mar. 31, 2019

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="margin-right: 10%; margin-left: 10%; 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="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;">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: 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;">Three Months Ended March 31,</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;"> <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;">March 31,</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;"> <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; padding-bottom: 1px;"> </td> </tr> <tr style="vertical-align: bottom;"> <td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; width: 36%; 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;">2019</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;">2019</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> </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: 13%; 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: 13%; 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;">20</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: 13%; 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;">22</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: 13%; 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;">25</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: 13%; 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: 13%; 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: 13%; 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: 13%; 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> </table></div>

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

	Three Months Ended March 31,
Country or Region	2019		2018
China	$	76,198	$	72,865
Taiwan		21,347		16,391
Europe		12,984		11,465
Korea		9,611		9,787
Southeast Asia		8,672		9,024
Japan		6,642		5,613
United States		5,806		3,755
Other		103		250
Total	$	141,363	$	129,150

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

	Three Months Ended March 31,
Product Family	2019		2018
DC to DC	$	132,711	$	119,268
Lighting Control		8,652		9,882
Total	$	141,363	$	129,150

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

	March 31,		December 31,
Country	2019		2018
China	$	98,117	$	93,096
United States		89,720		39,054
Taiwan		16,854		16,972
Other		806		879
Total	$	205,497	$	150,001