IGBT or MOSFET: Choose Wisely

The bipolar transistor was the only “real” power transistor until the MOSFET came along in the 1970’s. The bipolar transistor requires a high base current to turn on, has relatively slow turn-off characteristics (known as current tail), and is liable for thermal runaway due to a negative temperature co-efficient. In addition, the lowest attainable on-state voltage or conduction loss is governed by the collector-emitter saturation voltage VCE(SAT).
The MOSFET, however, is a device that is voltage- and not current-controlled. MOSFETs have a positive temperature coefficient,stopping thermal runaway. The on-state-resistance has no theoretical limit, hence on-state losses can be far lower. The MOSFET also has a body-drain diode, which is particularly useful in dealing with limited free wheeling currents.