Patent ID: 9673812
Date: 2017-06-06
CPC Classifications: H02M,H03K

Claim:
1. A gate driver that drives a field-effect transistor on the basis of an input signal, comprising: a comparator that compares an applied voltage applied between a drain and a source of the field-effect transistor to a reference voltage for detecting noise occurring between the drain and the source of the field-effect transistor; and a gate voltage switching circuit that, if the input signal indicates an instruction to turn off the field-effect transistor, and the field-effect transistor is off, switches a voltage applied between a gate and the source of the field-effect transistor from a first voltage to a second voltage when the output of the comparator transitions from a state indicating that the applied voltage between the drain and the source is less than the reference voltage to a state indicating that the applied voltage between the drain and the source is equal to or greater than the reference voltage; wherein, provided that Vth is a threshold voltage of the field-effect transistor, V1 is the first voltage, and V2 is the second voltage, a relationship Vth>V1>V2 is satisfied, and additionally, the second voltage is a negative voltage.