Drive circuit for an IGBT device.

摘要

A MOS transistor (QM) detects an increase of the collector current (IC) of an IGBT device (Q0). When an excess current flows, the transistor (QM) turns on, which restricts the gate voltage (VG) of the IGBT device (Q0) to decrease the collector current (IC). This protects the IGBT device (Q0) from the excess current. A Zener diode (DZ) placed in a path which is for detecting the excess current of the IGBT device (Q0) restricts the current passing through the path. This decreases a reactive power which is consumed in protecting the device (Q0) from the excess current while protecting a drive circuit from an erroneous operation.