Drive circuit for semiconductor element

摘要

A drive circuit wherein any abnormality of a semiconductor element is prevented from being erroneously sensed in a case where a gate “ON” command has entered in a state in which a gate voltage of the semiconductor element has not lowered fully. A detection process for a controlled variable of the semiconductor element is permitted only within a period which corresponds to a controlled variable of the semiconductor element at the time when an “ON” signal has been inputted to a control circuit, and a detected controlled variable which is detected within the period and a comparison controlled variable which is set in correspondence with the controlled variable are compared so as to output an abnormality signal, whereby the semiconductor element is turn-off at a speed lower than in normal turn-off.