Abstract: A drive circuit for driving a switching element on a SiC substrate, includes: a comparator for comparing a current flowing through the switching element with an overcurrent threshold; a determination unit for determining whether an overcurrent flows, based on a comparison result; a control unit for generating a drive signal for controlling a drive operation of the switching element based on a drive command, and for turning off the switching element when determining that the overcurrent flows; and a setting unit for variably setting the overcurrent threshold according to a physical quantity correlated with a voltage between main electrodes of the switching element.

Abstract: A switch driving circuit that drives a switch is provided. The switch driving circuit includes: a surge detecting unit that detects a surge voltage caused by switching of a state of the switch; a speed setting unit that sets, based on the surge voltage detected by the surge detecting unit, a switching speed of the switch when the state of the switch is switched; and a fault determination unit that determines whether a fault has occurred on the surge detecting unit. The speed setting unit is configured to change a setting of the switching speed to a fault setting when the fault determination unit determines that a fault has occurred on the surge detecting unit, from a normal setting in a state where the fault determination unit determines that no fault has occurred on the surge detecting unit, while maintaining driving of the switch.

Abstract: A drive circuit for driving a switching element on a SiC substrate, includes: a comparator for comparing a current flowing through the switching element with an overcurrent threshold; a determination unit for determining whether an overcurrent flows, based on a comparison result; a control unit for generating a drive signal for controlling a drive operation of the switching element based on a drive command, and for turning off the switching element when determining that the overcurrent flows; and a setting unit for variably setting the overcurrent threshold according to a physical quantity correlated with a voltage between main electrodes of the switching element.