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The difference between Schottky diode and ultrafast recovery diode

Column:Company News Time:2020-08-19 Browsing volume: 604

Fast recovery diodes refer to diodes with a short reverse recovery time (below 5us). Gold doping measures are often used in the process. The structure adopts a PN junction structure and some adopts an improved PIN structure. The forward voltage drop is higher than that of ordinary diodes (1-2V), and the reverse withstand voltage is mostly below 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 longer, and the latter is less than 100 nanoseconds. The Schottky diode is a diode based on the barrier formed by the contact between metal and semiconductor, referred to as Schottky Barrier Diode (Schottky Barrier Diode), which has a forward voltage drop (0.4-0.5V) and a short reverse recovery time (10- 40 nanoseconds), and the reverse leakage current is large, the withstand voltage is low, generally less than 150V, and it is mostly used in low voltage applications. These two kinds of tubes are usually used for switching power supplies.


The difference between a Schottky diode and a fast recovery diode: the recovery time of the former is about one hundred times shorter than the latter, and the reverse recovery time of the former is about a few nanoseconds. The former has the advantages of low power consumption, large current, and ultra-high speed! The electrical characteristics are of course diodes. Fast recovery diodes use gold doping and simple diffusion in the manufacturing process to achieve higher switching speeds and higher voltage resistance. At present, fast recovery diodes are mainly used as rectifier components in inverter power supplies. Schottky diode: The reverse withstand voltage is lower than 40V-50V, the on-state voltage drop is 0.3-0.6V, and the reverse recovery time is less than 10nS. It is a "metal semiconductor junction" diode with Schottky characteristics. Its forward 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. This kind of device is conducted by majority carriers, so its reverse saturation current is much larger than that of a PN junction with minority carriers.


Because the storage effect of the minority carriers in the Schottky diode is very small, its frequency response is only limited by the RC time constant. Therefore, it is an ideal device for high frequency and fast switching. Its operating frequency can reach 100GHz. And, MIS (metal-insulator-semiconductor) Schottky diodes can be used to make solar cells or light-emitting diodes. Fast recovery diode: There is a forward conduction voltage drop of 0.8-1.1V, a reverse recovery time of 35-85nS, and a rapid switch between on and off, which increases the frequency of use of the device and improves the waveform. Fast recovery diodes use gold doping and simple diffusion in the manufacturing process to achieve higher switching speeds and higher voltage resistance. At present, fast recovery diodes are mainly used as rectifier components in inverter power supplies.