IGBT Chip

An Insulated Gate Bipolar Transistor is a BJT that is built in a way that allows for fast switching with low power losses, making it ideal for use as a switch in high power circuits.  It is commonly packaged along with a flyback (also called freewheeling) diode, which prevents damage from inductive kickback.  These devices are often found in the output stages of switching power supplies, power amplifiers, motor drivers, and other power control circuits.