Can Schottky diodes be replaced with fast recovery diodes

Can Schottky diodes be replaced with fast recovery diodes

Can the fast recovery diode be replaced with a Schottky diode if there is a problem in the circuit?

In specific rectifier applications with low voltage withstand (below 400V), Schottky diodes can replace fast recovery diodes, provided that the voltage of the circuit cannot exceed the Schottky withstand voltage.. However, we do not recommend swapping because Schottky diodes have low reverse voltage withstand and forward voltage drop, making them suitable for low voltage rectification; Fast recovery with high reverse withstand voltage and large forward voltage drop, suitable for high voltage rectification. Replacing fast recovery with Schottky is prone to breakdown (unless it is confirmed that the withstand voltage meets the requirements), while using fast recovery instead of Schottky has high losses and low efficiency (unless efficiency is not considered).

In the application of Flyback diode, Schottky diode cannot be used to replace the fast recovery diode. Schottky is characterized by small conduction voltage and fast speed, but its weakness is also obvious, that is, the reverse withstand voltage is very small, usually only tens of volts. When it is used for Flyback diode, it is often accompanied by absorption reverse peak voltage. At this time, the problem of small reverse withstand voltage of Schottky transistor is exposed, so it is not suitable for replacement.

The difference between fast recovery diodes and Schottky diodes:

The main difference is in terms of recovery time, current, and withstand voltage. There are many specifications for the recovery time of fast recovery diodes, generally referred to as fast recovery diodes in the 500NS-35NS range, with 35NS ultra fast recovery diodes being a typical representative. The Schottky diode, on the other hand, adopts the barrier advantage and has a faster recovery time. Generally, it belongs to the Schottky series when it is less than 8NS, and Schottky diodes like ASEMI can reach a high level of 5NS. Secondly, Schottky diodes focus on forward high current resistance and reverse low voltage resistance, while fast recovery diodes focus on reverse high voltage resistance and forward current smaller than Schottky materials. It can be said that each has its own advantages, and selection needs to be treated specifically.