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., 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 regular PN junction diode. It belongs to the PIN junction type diode, which adds a base region I between the P-type silicon material and the N-type silicon material, forming 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).