| 摘要 |
The conduction losses in an IGBT U2 may be reduced by using a boosted gate voltage, but the short-circuit withstand time of the IGBT is undefined at such high gate voltages. The gate voltage is therefore quickly reduced to an unboosted level when a short-circuit circuit is detected, and the IGBT is then safely switched off at a time when the collector current has stabilised, for example after a predetermined delay. A short circuit may be detected by monitoring the collector voltage or by sensing the voltage across the emitter lead inductance Le, which voltage is proportional to di/dt. The technique may be applied also to MOSFETs and JFETs. |
