The role of fast recovery diode

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The role of fast recovery diode [Copy link]

Usually used for higher frequency rectification and freewheeling products. Used in the input part of the power module. The frequency is not high, so fast recovery diodes are not needed and ordinary diodes can be used. Relative to a diode, when the voltage applied to its two ends changes from forward to reverse, the response time is generally very short, and conversely, the time from reverse to forward is relatively long, which is the reverse recovery time. When the diode is used for high-frequency rectification, etc., a very short reverse recovery time is required. At this time, a fast recovery diode (FRD), a higher ultra-fast recovery diode (SRD), or a switching diode is needed. The fastest one is the Schottky diode (its principle is different from the above diodes) The fast recovery diode (FRD for short) is a semiconductor diode with good switching characteristics and short reverse recovery time. It is mainly used in electronic circuits such as switching power supplies, PWM pulse width modulators, and frequency converters as high-frequency rectifier diodes, freewheeling diodes or damping diodes. Function of fast recovery diodes The internal structure of the fast recovery diode is different from that of the ordinary PN junction diode. It belongs to the PIN junction diode, that is, the base region I is added between the P-type silicon material and the N-type silicon material to form a PIN silicon wafer. Because the base region is very thin and the reverse recovery charge is very small, the reverse recovery time of the fast recovery diode is short, the forward voltage drop is low, and the reverse breakdown voltage (withstand voltage value) is high. Usually, 5~20A fast recovery diodes are packaged in TO-220FP plastic, high-power fast recovery diodes above 20A are packaged in TO-3P plastic with a metal heat sink on the top, and fast recovery diodes below 5A are packaged in DO-41, DO-15 or DO-27 plastic packages.