What are the main parameters of fast recovery diodes? How does the reverse recovery time of the fast recovery diode work?

What are the main parameters of fast recovery diodes? How does the reverse recovery time of the fast recovery diode work?

The reverse recovery time of the fast recovery diode is the time interval during which the current transitions from forward to reverse through zero, and then from reverse to a specified low value. In fact, it releases the charge stored in the diffusion capacitance of the PN junction during the forward conduction period of the fast recovery diode. The reverse recovery time determines how high a frequency continuous pulse the fast recovery diode can be used as a switch. If the duration of the reverse pulse is shorter than the reverse recovery time, the fast recovery diode cannot function as a switch if it can conduct in both forward and reverse directions.

The amount of charge stored in the PN junction and the reverse voltage together determine the reverse recovery time, which will not only increase its loss under high-frequency pulse, but also cause greater electromagnetic interference. So it is necessary to know the reverse recovery time of the fast recovery diode. It is necessary to select the fast recovery diode correctly and design the circuit reasonably. When selecting the fast recovery diode, it is recommended to try to choose one with a small PN junction capacitance and short reverse recovery time, but most manufacturers do not provide this parameter data.