An investigation of the drive circuit requirements for the power insulated gate bipolar transistor (IGBT)

The drive circuit requirements of the OGBT are explained with the aid of an analytical model. This model can be used to describe the turn-on and turn-off, gate and anode, current and voltage waveforms for general external drive, load, and feedback circuits. It is shown that nonquasi-static effects limit the influence of the drive circuit on the time rate-of-change of the anode voltage. Model results are compared with measured turn-on and turn-off waveforms for different drive, load, and feedback circuits and for different IGBT base lifetimes. The effective output capacitance of the IGBT at turn-off is several orders of magnitude larger than that of the structurally equivalent power MOSFET and depends upon the device base lifetime because the base charge at turn-off depends upon the device base lifetime. However, the gate drain feedback capacitance is unchanged from the value for the structurally equivalent power MOSFET. Thus, the minimum gate resistance that influences the anode voltage rate-of-rise at turn-off is several orders of magnitude larger than that for the power MOSFET and varies with device base lifetime.<
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