| 主权项 |
1. A gate driver comprising:
a gate reference voltage generation circuit configured to output a gate reference voltage as a reference for a drive voltage to turn ON a first transistor, the gate reference voltage generation circuit further configured to change the gate reference voltage to be outputted between at least two values; a constant current circuit configured to supply constant current to a gate of the first transistor; a second transistor connected in a forward direction in series between the constant current circuit and the gate of the first transistor in a gate current supply path from a power supply voltage (VD) through the constant current circuit to the gate of the first transistor, the second transistor being an N channel or NPN transistor and having a gate supplied with the gate reference voltage; a drive controller configured to drive the gate of the first transistor with the constant current by operating the constant current circuit when an ON instruction is inputted; a voltage change controller configured to set a value of the gate reference voltage to be outputted by the gate reference voltage generation circuit to a first setting value or a second setting value greater than the first setting value, and an overcurrent detector configured to determine whether the first transistor is in an overcurrent state where excessive current greater than a predetermined failure threshold flows in the first transistor, wherein the voltage change controller sets the value of the gate reference voltage so that the value of the gate reference voltage is the first setting value when the ON instruction is inputted and then changes the value of the gate reference voltage from the first setting value to the second setting value when a predetermined transition timing comes after a Miller period of the first transistor ends under a condition where the overcurrent detector does not determine that the first transistor is in the overcurrent state. |
