SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES:

Segment Reporting

The Company is organized and operates as one reportable segment, the design, development, manufacture and marketing of integrated circuits and related components for use primarily in the high-voltage power-conversion market. The Company’s chief operating decision maker, the Chief Executive Officer, reviews financial information presented on a consolidated basis for purposes of making operating decisions and assessing financial performance.

Customer Concentration

The Company's top ten customers accounted for approximately 52% of net revenues for the three months ended March 31, 2019, and approximately 58% of net revenues in the corresponding period of the previous year. A significant portion of these revenues are attributable to sales of the Company’s products to distributors of electronic components. These distributors sell the Company’s products to a broad, diverse range of end users, including OEMs and merchant power supply manufacturers. Sales to distributors were $69.8 million and $79.1 million in the three months ended March 31, 2019 and 2018, respectively. Direct sales to OEMs and power-supply manufacturers accounted for the remainder.

In each of the three months ended March 31, 2019 and 2018, one customer, a distributor of the Company's products, accounted for more than 10% of the Company’s net revenues.

The following table discloses this customer’s percentage of revenues for the respective periods:



	Three Months Ended
Customer	March 31, 2019		March 31, 2018
Avnet	13	%	16	%

No other customers accounted for 10% or more of the Company’s net revenues in the periods presented.

Concentration of Credit Risk

Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash investments and trade receivables. The Company does not have any off-balance-sheet credit exposure related to its customers. As of March 31, 2019, and December 31, 2018, 68% and 64%, respectively, of accounts receivable were concentrated with the Company’s top ten customers.

The following customers represented 10% or more of accounts receivable:



Customer	March 31, 2019		December 31, 2018
Avnet	18	%	17	%
Powertech Distribution Ltd.	11	%	11	%

No other customers accounted for 10% or more of the Company’s accounts receivable in the periods presented.

Geographic Net Revenues

The Company markets its products globally through its sales personnel and a worldwide network of independent sales representatives and distributors. Geographic net revenues, based on “bill to” customer locations, for the three months ended March 31, 2019, and March 31, 2018, were as follows:



	Three Months Ended
(In thousands)	March 31, 2019		March 31, 2018
United States of America	$	2,672	$	3,867
Hong Kong/China	47,229		51,357
Taiwan	6,672		11,886
Korea	8,542		9,649
Western Europe (excluding Germany)	10,901		13,592
Japan	3,650		4,551
Germany	4,927		3,304
Other	4,595		4,875
Total net revenues	$	89,188	$	103,081