Characteristics of fast recovery rectifier diode

Fast recovery rectifier diode belongs to the high-frequency rectifier diode in rectifier diodes. It is called a fast recovery diode because ordinary rectifier diodes generally operate at low frequencies (such as 50Hz mains frequency), with a working frequency below 3kHz. When the working frequency is between tens to hundreds of kHz, the time for forward and reverse voltage changes is slower than the recovery time, and ordinary rectifier diodes cannot achieve unidirectional conduction normally. In this case, a fast recovery rectifier diode is needed.

The characteristic of a fast recovery diode is its short recovery time, which makes it suitable for high-frequency (such as line frequency in televisions) rectification. The fast recovery diode has an important parameter that determines its performance - reverse recovery time. The definition of reverse recovery time is the time required for a diode to rapidly transition from a forward conducting state to a cutoff state, from the output pulse dropping to the zero line, to the reverse power supply recovering to 10% of the maximum reverse current, commonly represented by the symbol trr. The trr of ordinary fast recovery rectifier diodes is several hundred nanoseconds (10-9 seconds), while the trr of ultra fast recovery diodes is generally several tens of nanoseconds. The smaller the Trr, the higher the operating frequency of the fast recovery diode.