as a method of simply detecting the

as a method of simply detecting the occurrence of a short circuit without detecting the collector current a method of detecting the on-voltage(v) when the IGBT is on is often used , igbt drivers etc. with built-in short circuit protection function are also on the market .The short-circuit protectiom circuit built in the IGBT driver judges the short circuit condition when the gate output is on and the collector potential of the IGBT is high ,then shuts off the gate voltage. Since surge voltage (C-E) becomes high when cutting off a large current quickly we recommend a method to suppress the gate voltage softly to suppress the surge voltage(c-E)