The difference between fast recovery diodes

1. Fast recovery diodes refer to diodes with short reverse recovery time (below 5us). Gold-doped measures are often used in technology, PN junction structure is adopted in structure, and some improved PIN structure is adopted. Its forward voltage drop is higher than that of ordinary diodes (1-2V), and the reverse voltage is less than 1200V. In terms of performance, it can be divided into two levels: fast recovery and ultra-fast recovery. The reverse recovery time of the former is hundreds of nanoseconds or more, while that of the latter is less than 100 nanoseconds.
Schottky diodes are diodes based on the potential barrier formed by the contact between metal and semiconductors. it has the advantages of forward voltage reduction (0.4 ~ 0.5V), short reverse recovery time (10-40 nanoseconds), large reverse leakage current and low voltage resistance, which is generally lower than 150V, so it is often used in low voltage applications.
These two kinds of diodees are commonly used in switching power supplies,
The difference between Schottky diodes and fast recovery diodes: the recovery time of the former is about 100 times smaller than that of the latter, and the reverse recovery time of the former is about a few nanoseconds!
The former also has the advantages of low power consumption, high current and ultra-high speed. Of course, the electrical characteristics are diodes!
High switching speed and high voltage withstand can be obtained by using gold doping and simple diffusion in the manufacturing process of fast recovery diodes. At present, fast recovery diodes are mainly used as rectifier components in inverter power supplies.
Schottky diode: the reverse voltage withstand value is low 40V-50V, and the on-state voltage drop is 0.3-0.6V, which is less than the reverse recovery time of 10nS. It is a "metal semiconductor junction" diode with Schottky characteristics. The positive starting voltage is low. In addition to materials, the metal layer can also be made of gold, molybdenum, nickel, titanium and other materials. Its semiconductor materials are silicon or gallium arsenide, mostly N-type semiconductors. The device is conducted by many carriers, so the reverse saturation current of the device is much larger than that of the PN junction conducted by a few carriers. Because the storage effect of minority carriers in Schottky diodes is very small, its frequency response is only limited by the RC time constant, so it is an ideal device for high frequency and fast switching. Its working frequency can reach 100GHz. Moreover, MIS (metal-insulator-semiconductor) Schottky diodes can be used to make solar cells or light-emitting diodes.
Fast recovery diode: with a forward guide voltage drop of 0.8V-1.1V and a reverse recovery time of 35-85nS, it can quickly switch between turn-on and cut-off, increasing the frequency of the device and improving the waveform. High switching speed and high voltage withstand can be obtained by using gold doping and simple diffusion in the manufacturing process of fast recovery diodes. At present, fast recovery diodes are mainly used as rectifier components in inverter power supplies.
Generally speaking, the fast recovery diodes of 5A and 20A are packaged in TO-220FP plastic package, the high-power fast recovery diodes above 20A are packaged in TO-3P plastic package with metal heat sink at the top, and the fast recovery diodes below 5A are packaged in DO-41,DO-15 or D0-27 plastic packages.