Fast recovery diode refers to the diode with very short reverse recovery time (below 5us). Gold doping measures are used in the process, and PN junction structure is used in the structure, and some are improved PIN structure. The forward voltage drop is higher than that of ordinary diodes (1-2V), and the reverse voltage is more than 1200V. From the performance, it can be divided into two levels: fast recovery and super fast recovery. The former reverse recovery time is in the order of hundreds of nanoseconds or more, while the latter is below 100 nanoseconds.