Protective circuit for series-connected power semiconductors

Abstract

A semiconductor assembly with overvoltage protection is provided. The semiconductor assembly comprises at least two series connected power semiconductors, each of which is protected by at least one overvoltage protection device. The overvoltage protection device is activated at a predetermined voltage. The overvoltage protection device may be coupled in parallel across the emitter and collector of the power semiconductor or between the collector and gate of the power semiconductor. The overvoltage protection device includes a capacitor and a rectifier connected in series with the capacitor. The rectifier prevents the capacitor from discharging when the power semiconductor is in a conducting state. A voltage controller is connected to the capacitor and determines the voltage level to which the capacitor is discharged after an activation of the overvoltage protection device.

Dependencies are inferred from the claim text.