Driver circuit for sinking current to two supply voltages

摘要

An insulated gate bipolar transistor (IGBT) gate driver circuit with a push-pull output stage which provides current sinking to two power supply rails. Current sinking to a low impedance power supply rail (GND) via a high current NPN bipolar transistor provides fast IGBT turn off. A PNP bipolar transistor forward biased emitter-base junction in series with an N channel field effect transistor provides current-limited current sinking to a higher impedance power supply rail (VEE). The on resistance of the N channel field effect transistor can be chosen to set the maximum current drawn from the higher impedance VEE power supply rail. This current-limiting avoids the need for a second low impedance power supply. The transition of the output of the driver from ground to VEE is only a function of the output voltage output by the driver. It is not a function of any timed switching of transistors.