Patent ID: 6326819
Filing Date: 2001-12-04
Classification: H03K

Abstract:
A circuit comprising a current buffer for a gate driver for driving an insulated gate bipolar transistor, wherein the insulated gate bipolar transistor has equilibrium states including an ON state and an OFF state and wherein the insulated gate bipolar transistor transitions between the equilibrium states; said current buffer comprising:a resistive path electrically coupling the gate driver to a gate of the insulated gate bipolar transistor, wherein a first equilibrium current maintaining the insulated gate bipolar transistor in the ON state and a second equilibrium current maintaining the insulated gate bipolar transistor in the OFF state flow solely through the resistive path;first and second switching devices, wherein the first switching device is coupled between a first voltage potential and the gate of the insulated gate bipolar transistor, wherein the second switching device is coupled between a second voltage potential and the gate of the insulated gate bipolar transistor, wherein control inputs of the first and second switching devices are coupled to the gate driver, whereinwhen a signal from the gate driver commands transition of the insulated gate bipolar transistor from one of the equilibrium states to the other, one of the first and second switching devices switches on to provide a transition current to the insulated gate bipolar transistor during the transition and switches off after the transition in response to a voltage of the gate fed back to the first and second switching devices, wherein the first and second switching devices are switched off when the insulated gate bipolar transistor is in the ON state and when the insulated gate bipolar transistor is in the OFF state.