Patent ID: 9065443
Filing Date: 2015-06-23
Classification: H02M,H03K

Abstract:
1. An inverter drive device that drives an inverter circuit including a power semiconductor element, comprising: a drive circuit that outputs a gate voltage of the power semiconductor element on the basis of a PWM signal; an over-current protection circuit that acquires an emitter electrode side voltage of the power semiconductor element, and, if that voltage is greater than a first predetermined voltage value that is determined in advance, outputs a fault signal to the drive circuit for stopping the output of the gate voltage after a first predetermined time interval has elapsed from the acquisition of the emitter electrode side voltage; and a Zener clamping protection circuit that acquires the emitter electrode side voltage of the power semiconductor element, and, if that voltage is greater than a second predetermined voltage value that is determined in advance, performs clamping of the gate voltage of the drive circuit after a second predetermined time interval has elapsed from the acquisition of the emitter electrode side voltage; wherein the Zener clamping protection circuit comprises a latch circuit that, after the emitter electrode side voltage has been acquired, continues the clamping of the gate voltage by the Zener clamping protection circuit during an interval that is greater than the first predetermined time interval.