How to use fast recovery diodes in rectifier circuits?

How to use fast recovery diodes in rectifier circuits?

fast recovery diodes are widely used in circuits, so how can fast recovery diodes be used in rectifier circuits?

Due to the low frequency of the rectifier circuit, there is only a requirement for withstand voltage. As long as the withstand voltage can be met, it can definitely be replaced, and fast recovery diodes are also used for rectification. In the secondary rectification part of the switching power supply, due to the high frequency, only fast recovery diodes can be used for rectification. Otherwise, due to excessive diode loss, the overall efficiency of the power supply will be reduced, and in severe cases, the diode will be burned.

In addition, the price of fast recovery diodes is much higher than that of rectifier diodes, and the higher the withstand voltage, the more expensive it becomes. Therefore, fast recovery second-generation transistors are generally not used. However, in high-frequency rectification situations such as power output, ordinary diodes recover very slowly in the conduction state. When the reverse voltage is rapidly applied, it is still in the conduction state. The carriers accumulated in the PN junction for forward conduction directly flow in reverse, resulting in a large reverse current and losing the "rectification" function. Therefore, it is necessary to use a fast recovery diodes.