What is the difference between the function of fast recovery diode and rectifier bridge? — SUNMATE
What is the difference between the function of fast recovery diode and rectifier bridge?
The performance parameters of the fast recovery diode are between the Schottky diode and the ordinary rectifier diode. The Schottky diode has low on voltage (not as low as Schottky diode), fast speed, and relatively high withstand voltage (Schottky withstand voltage is generally very low). The fast recovery diode is mainly used for rectification in high-frequency occasions, such as the secondary rectification of switching power supply, which is used for the rectification of mains power. The fast recovery diode has no problem, However, due to the material and process of the fast recovery diode, its PN junction is thinner than that of the ordinary rectifier tube, and its ability to generate large current at an instant is weaker than that of the ordinary rectifier tube. Especially when the filter capacitor is too large, the improper selection of the maximum current of the tube will burn the fast recovery PN junction at an instant.
In addition, fast and ultrafast among fast diodes refer to the speed of diode reverse turn-off. If the rectified square wave is useful, the sine wave is useless. The reverse recovery time of the fast recovery diode is short, and the reverse recovery time of the common rectifier diode is long. The fast recovery diode is used in the circuit with higher frequency, and the common rectifier diode is used in the circuit with lower frequency (power frequency 50Hz). The popular point is that high-frequency power supply requires high-frequency diode rectification. The general switching power supply 5v3.3v is Schottky. No matter how high the voltage is, it will recover quickly. There are also 12V Schottky ones. It is difficult for Schottky to withstand voltage.
There are many kinds of fast recovery diodes, which can be selected according to the needs of the circuit in the galloping machine rectifier. Due to the different transistors and electronic tubes, the overload capacity is low. When selecting, it is necessary to consider leaving a large current and voltage margin to improve the reliability.