DRIVE CIRCUIT FOR CURRENT SENSE IGBT

摘要

A drive circuit having, in addition to a fault discrimination operational circuit for detecting an overcurrent of the current sense IGBT (Q1), a capacitor (C2) operatively connected in parallel to the gate-emitter of the current sense IGBT, and a transistor (T4A) for discharging the capacitor via a resistor (R2). In case of short-circuit fault, an overcurrent is detected by the fault discrimination operational circuit (100), and the transistor is turned on via the operational circuit. The gate voltage of the IGBT is gradually declined to turn off the IGBT. This enables the IGBT to be protected from a transitional overvoltage across the collector and emitter of the IGBT.