Patent ID: 9444448
Filing Date: 2016-09-13
CPC Classification: H02M,H03K

Claim Text:
1. A gate drive circuit for applying a gate voltage to a gate of a transistor, the gate drive circuit comprising: a gate resistor; an active gate control circuit, the active gate control circuit configured to apply a first voltage via the gate resistor to the gate of the transistor to turn on the transistor, the first voltage being greater than a threshold voltage for the transistor, the active gate control circuit further configured to apply a second voltage via the gate resistor to the gate of the transistor to turn off the transistor, the second voltage being less than the threshold voltage; wherein during turn off of the transistor, the active gate control circuit is further configured to apply a third voltage to the gate of the transistor for a first turn off period, the third voltage being less than the first voltage but greater than the second voltage, the active gate control circuit further configured to apply a fourth voltage to the gate of the transistor for a second turn off period, the second turn off period corresponding to a period of reverse recovery of a diode coupled in parallel with the transistor, the fourth voltage being less than the third voltage but greater than the second voltage; wherein the active gate control circuit is configured to receive a feedback signal indicative of a collector current of the transistor.