IGBTs, or insulated gate bipolar transistors, are one of the predominant transistor technologies used in high-power switching applications. For the sake of comparison, this slide will briefly discuss the two other types of transistors. First, the BJT, or bipolar junction transistor, developed around 1948 is a current-controlled device. It has a base, a collector, and an emitter. These devices are typically low-current devices and may have more complex drive circuits. Then sometime around 1959, the MOSFET, or metal oxide field effect transistor, was developed. This is a voltage-controlled device with a simpler drive circuit and has a gate, a drain, and a source. Lastly, sometime around 1974, the insulated gate bipolar transistor was born. This device combines the voltage-controlled gate of a MOSFET, and the collector/emitter structure of a BJT to form a transistor that is capable of handling high voltage and high current with a simpler drive circuit.