Analysis of integrated thyristor switching-off by a reverse gate pulse current

Abstract

To increase the maximum power current density of an integrated n⁺p'Nn'p⁺-type thyristor during switching-off by a current pulse in the control circuit, the injection of electrons from the n⁺ emitter should be interrupted before the recovery of the collector p'N junction. This has been done using a rapidly increasing reverse gate current pulse with an amplitude equal to the amplitude of the power switched-off current. After the interruption of the emitter injection, the remaining current through the device is the current of holes extracted from the collector region via the gate electrode. Like in insulated gate bipolar transistors (IGBTs), the physical mechanism that limits the maximum density of the switch-off current is the dynamic avalanche breakdown, which is initiated by the holes extracted through the space charge region of the collector p'N junctions.