High gain power switching using field controlled thyristors

Abstract A technique for high gain power switching using field controlled thyristors is described. This technique uses a MOSFET connected in series with the FCT to control the current flow. The circuit exhibits normally-off behavior and is capable of operation at high voltages. The current through the FCT can be turned on and off by the application of a low voltage gate signal to the MOSFET. Turn-on and turn-off times of less than 1 μs have been observed at a current gain of over 30. The new gating technique offers the advantage of the large operating current density of the FCT even at high breakdown voltages and the high input impedance of the MOS gate used to trigger the device during power switching.