Overcurrent Protection Method for Composite Power Semiconductor Switches

Various examples are provided related to overcurrent protection for composite power semiconductor switches comprising a high voltage power switch in series with a low voltage non-linear element. In one example, a system includes a blocking diode connected to a sensing node of a composite switching device; a resistor connected in series with the blocking diode and to a desaturation detection input of a gate driver circuit; and a blanking capacitor connected between the desaturation detection input and a common voltage reference of the gate driver circuit. The gate driver circuit can detect a short circuit condition based upon a sensed voltage at the desaturation detection input. In another example, a method includes sensing a voltage on a blanking capacitor, the voltage provided from a sensing node of a composite switching device via a blocking diode and a resistor, and detecting a short circuit condition based upon the sensed voltage.