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.