The amplifying gate thyristor

High frequency, high current operation of thyristors requires simultaneous consideration of turn-off time, di/dt and dv/dt capability. The frequency of operation and the type of circuit dictate the turn-off time and dv/dt which are required of a device. These two parameters are established by suitable gold doping to control the minority carrier lifetime and by employing "shorted emitter" techniques to ccntrol the low current alpha's of the device. In addition, at high currents and voltages, a thyristor's capability of withstanding steep wavefront, high current pulses (i.e., di/dt capability) often also proves to be a major limiting factor in its application. This characteristic is primarily determined by the instantaneous junction temperature; thus, it is essential that localized heating be minimized. Unfortunately, this problem is aggravated by increased dissipation resulting from the lower lifetime that is required to achieve the short turn-off time. In order to minimize the instantaneous temperature rise, a substantial increase in effective conducting area during the turn-on interval is required.