Patent ID: 8922259

Claim:
A gate drive circuit comprising: a drive voltage generation circuit that outputs a drive voltage for performing an ON drive of a transistor and has a function which switches a voltage value of the drive voltage to be output in at least two levels; a current regulator circuit that outputs a constant electric current toward a gate terminal of the transistor from an output terminal of the drive voltage generation circuit; a drive control section that operates the current regulator circuit for performing a constant electric current drive of the gate of the transistor when an ON command is inputted; and a voltage switchover control section that sets the voltage value of the drive voltage generated by the drive voltage generation circuit to one of a first set value and a second set value that is lower than the first set value, wherein the voltage switchover control section sets the voltage value of the drive voltage to the first set value when the ON command is inputted, and the voltage switchover control section switches the voltage value of the drive voltage from the first set value to the second set value at a predetermined switch timing after an end of the mirror period of the transistor.