Power Electronics and Motor Drive Systems

10.3. Insulated Gate Bipolar Transistor (IGBT)

The bipolar transistor was the only power transistor until the MOSFET came along in the 1970s. The bipolar transistor requires a high base current to turn-on and has relatively slow turn-off characteristics. In addition, the lowest attainable conduction-state voltage or conduction loss is governed by the collector–emitter saturation voltage V_CE(SAT). However, the MOSFET is a voltage-controlled semiconductor device and not current controlled as the transistor. MOSFETs have a positive temperature coefficient, stopping thermal runaway. The conduction-state resistance has no theoretical limit and, consequently, conduction-state losses can be by far lower. The main disadvantage of the MOSFETs is that they ...