FMMT411T NPN Low Voltage Avalanche Transistor Diodes Incorporated FMMT411T NPN Low Voltage Avalanche Transistor is a silicon planar bipolar transistor designed for operating in avalanche mode. Tight process control and low inductance packaging combine to produce high-current pulses with fast edges. The FMMT411T is specifically designed for Low Voltage Avalanche Mode Operation, and has an 80A Peak Avalanche Current.