Semiconductor device drive circuit

摘要

A semiconductor device drive circuit comprises first drive means (13) for driving an IGBT (1), second drive means (13) for driving the IGBT (1) at lower speed than the first drive means (12) and switch means (11) for switching output of the first drive means (12) and output of the second drive means (12) for supply to a gate of the IGBT (1). Current decrease start point detection means (14) detect a current decrease start point when a transition is made from a first period in which change in a collector current is moderate to a second period in which change in the collector current is abrupt when the IGBT is turned off. The switch means (11) are operated so as to use the first drive means in the first period and the second drive means in the second period in response to output of the current decrease start point detection means (14).