It stands for Insulated Gate Bipolar Transistor. It is a voltage-controlled device that has an insulated gate with an oxide insulating film. The gate structure is similar to a MOSFET. It combines the positive characteristics of a MOSFET and bipolar transistor. It is an indispensable component in a power conversion circuit for high-voltage and large-current applications. It is mainly used in consumer equipment such as air conditioners (a/c) or microwave ovens, industrial equipment such as elevators, and inverters for hybrid electric vehicles (HEV) and electric vehicles (EV).