Patent ID: 9590612
Date: 2017-03-07
CPC Classifications: H01L,H02M,H03K

Claim:
1. A drive circuit of a voltage-controlled device, the drive circuit comprising: a constant current circuit configured to supply a constant current to a gate of the voltage-controlled device to turn on the voltage-controlled device; a discharge circuit configured to supply a discharge current from the gate of the voltage-controlled device to turn off the voltage-controlled device; a switch circuit configured to operate either one of the constant current circuit or the discharge circuit depending on a drive signal to turn on or turn off the voltage-controlled device; a current instruction value generation circuit comprising a constant current source arranged separately from the constant current circuit and a resistance selection unit configured to select at least one of a plurality of resistances connected in parallel with each other between the constant current source and the ground, and configured to generate a voltage between the constant current source and the resistance selection unit, as a current instruction voltage; and a current control circuit configured to control an output current from the constant current circuit based on the current instruction voltage generated by the current instruction value generation circuit.