Cascoded semiconductor devices

摘要

A cascoded power semiconductor circuit is provided for power switches based on depletion-mode (normally on) devices. The control circuit makes use of a bootstrap arrangement that allows an active control of both power switches of a cascode circuit using a single gate driver.

主权项

1. A cascode transistor circuit comprising:
a gallium nitride field effect transistor (FET) or a silicon carbide insulated gate field effect transistor (FET) having its drain connected to a high power rail; a silicon MOSFET with its drain connected to the source of the gallium nitride or silicon carbide FET and its source connected to a low power rail; a bootstrap capacitor connected between the gates of the gallium nitride or silicon carbide FET and the silicon MOSFET; and a diode with its anode connected to the gate of the gallium nitride or silicon carbide FET and its cathode connected to the low power rail, the diode being configured and arranged to permit the bootstrap capacitor to be changed during a period when the FET is switched on or active.