BI-FET CASCODE POWER SWITCH

摘要

Power switch devices for high-speed applications are disclosed. The power switch device includes a depletion mode field effect transistor (D-FET), an enhancement mode field effect transistor (E-FET) and a bipolar transistor. In one embodiment, the E-FET is coupled in cascode with the D-FET such that turning off the E-FET turns off the D-FET and turning on the E-FET turns on the D-FET. Furthermore, the bipolar transistor is operably associated with the D-FET and the E-FET such that turning on the bipolar transistor drives current from the D-FET through the bipolar transistor to the E-FET to provide a charge that turns on the E-FET. The bipolar transistor provides several advantages such as a higher Schottky breakdown voltage for the E-FET and faster current switching speed for the power switch device.