Fast Recovery Diode (FRD) is a semiconductor diode with good switching characteristics and short reverse recovery time. It is mainly used in electronic circuits such as switching power supplies, PWM pulse width modulators, frequency converters, etc., and is used as a high-frequency rectifier diode, freewheeling diode, or damping diode. The internal structure of a fast recovery diode is different from that of a common PN junction diode. It belongs to a PIN junction type diode, which adds a base region I between the P-type silicon material and the N-type silicon material to form a PIN silicon wafer. Due to the thin base region and low reverse recovery charge, the fast recovery diode has a shorter reverse recovery time, lower forward voltage drop, and higher reverse breakdown voltage (withstand voltage).