Semiconductor switch having a disconnectible thyristor

摘要

A semiconductor switch has a disconnectible thyristor, a first switching transistor connected to a lead of the thyristor and a turn-off current path which emits a control electrode of the thyristor to a terminal of the lead. Given such semiconductor switches, the critical voltage rise rate dU/dt is increased for an inhibit voltage up to which an undesired ignition of the thyristor is reliably avoided. This is achieved by providing a second switching transistor having its switching path connected in the turn-off current path. Both switching transistors are conductive in the inhibiting condition of the thyristor and form a stabilizing emitter-base short.