BJT s are rated up to 1000V, 500A and can operate at frequencies up to 50kHz. With zero gate voltage, the device will block current whilst a potential of up to a few hundred volts is applied. At very low values of drain source voltage the device has a constant resistance characteristic but at higher values it is controlled by the gate voltage. For switching applications, it is essential that the device is operating in the constant resistance region, the gate voltage must be limited to about 20 volts though. Switching characteristics are similar to those found for the BJT, but the turn off time is very fast, in the order of 50nsec.
Devices are very sensitive to voltage spikes, especially the gate.
Snubber circuits are used to protect the gates. 1000V 200A 20nsec. The device does not exhibit secondary breakdown, and has a low conduction loss.