Note 1 - Description of Business

12 Months Ended

Mar. 31, 2017

Notes to Financial Statements

Nature of Operations [Text Block]

1.

Description of Business

We design, develop, manufacture and market power semiconductors, digital and analog integrated circuits, or ICs, and systems and radio frequency, or RF, power semiconductors.

Power semiconductors are used primarily in controlling energy in motor drives, power conversion including uninterruptible power supplies and switch mode power supplies and medical electronics. Our power semiconductors convert electricity at relatively high voltage and current levels to create efficient power as required by a specific application. Our target market includes segments of the power semiconductor market that require medium to high power semiconductors, with a particular emphasis on high power semiconductors. Our power semiconductors include power metal-oxide-silicon field-effect transistors, or MOSFETs, insulated-gate bipolar transistors, or IGBTs, thyristors and rectifiers, including fast-recovery epitaxial diodes, or FREDs. Our ICs include solid state relays, or SSRs, for telecommunications applications and power management and control ICs, such as current regulators, motion controllers, digital power modulators and drivers, and microcontrollers such as embedded flash microcontrollers and

8

-bit microcontrollers. Our systems include laser diode drivers, high voltage pulse generators and modulators, and high power subsystems, sometimes known as stacks, that are principally based on our high power semiconductor devices.

We sell products in North America, Europe and the Middle East and Asia through an organization that includes direct sales personnel, independent representatives and distributors. We are headquartered in Northern California with principal operations in Massachusetts, the Netherlands, Germany, the Philippines and the United Kingdom, or UK. Each site has manufacturing, research and development and/or sales and distribution activities. We also make use of subcontract manufacturers for fabrication of wafers and for assembly and test operations. Our fiscal years end on

March 31.

References to any numerically identified year preceded by the word “fiscal” are references to the year ended or ending on

March 31

of such numerically identified year.