Power semiconductor device with low on-state voltage

摘要

A circuit connecting a sub-IGBT element S2 having a smaller current capacity and a smaller saturated current than the main IGBT element S1 and a resistance R1 in series is connected to the main IGBT element S1 in parallel, a MOSFET element S3 being connected between the gate electrode of the sub-IGBT element S2 and the emitter electrode of the main IGBT element S1, a delay element being connected between the gate electrode of the sub-IGBT element S2 and the gate electrode of the main IGBT element S1. In normal operation, the ON-state voltage is small and low loss can be realized. In the event of a short-circuit accident, the sub-IGBT element S2 detects the short-circuit before the main IGBT element S1 turns on to prevent an over-current from flowing in the main IGBT element S1, which substantially improves the short-circuit resistivity of the semiconductor device.