Patent ID: 7710187

Claim:
A gate drive circuit comprising a turn-on side circuit for turning on a gate of a power switching device, said turn-on side circuit including a first turn-on side power supply circuit and a second turn-on side power supply circuit, said first turn-on side power supply circuit including: a first turn-on voltage source for supplying a first turn-on voltage; first turn-on wiring connected between said first turn-on voltage source and said gate of said power switching device; and a first turn-on switch connected in said first turn-on wiring and controlled by a gate drive signal; and said second turn-on side power supply circuit including: a second turn-on voltage source for supplying a second turn-on voltage applied to said gate of said power switching device to set said power switching device in a steady (on) state; second turn-on wiring connected between said second turn-on voltage source and said gate of said power switching device; a second turn-on switch connected in said second turn-on wiring; and a turn-on side delay circuit for delaying said gate drive signal and passing it to said second turn-on switch; wherein said first and second turn-on voltages are higher than a threshold voltage of said power switching device, and said first turn-on voltage is lower than said second turn-on voltage.