Patent ID: 7489166

Claim:
A gate drive circuit for driving the gate of a power transistor switch, the gate drive circuit comprising: a gate drive sourcing circuit supplying gate drive current to the power transistor switch, the gate drive sourcing circuit initially providing a first current to the gate of the power transistor switch and then providing a second current to the gate of the power transistor switch; a circuit for driving the gate drive sourcing circuit, said circuit having a first input for driving the gate drive sourcing circuit to turn on the power transistor switch by providing said first current, said circuit further having a second input coupled to a voltage across the power transistor switch and being controlled by said second input to cause said gate drive sourcing circuit to provide said second current when the voltage across said power transistor switch begins to drop as said power transistor switch begins to turn on; and further comprising a further transistor coupled to said first input and being controlled by said first input to prevent said at least one second transistor from being turned on when said power transistor switch should not be turned on, wherein said circuit for driving the at least one first transistor and the at least one second transistor includes a detection circuit for detecting when said voltage across said power transistor switch begins to drop.