Learn about the pros and cons of Schottky diodes

Get a quick overview of the pros and cons of Schottky diodes

Schottky diodes are common in electronic applications, so what are the advantages and disadvantages of Schottky diodes?

Schottky diode advantages:

Schottky diodes have the advantages of high switching frequency and forward voltage drop, but their reverse breakdown voltage is relatively low, most of them are not higher than 60V, and the highest is only about 100V, so that their application range is limited. For example, in switching power supply (SMPS) and power factor correction (PFC) circuits, only fast recovery epitaxial diodes (FRED) and ultra-fast recovery diodes (UFRD) are used for freewheeling diodes of power switching devices, high-frequency rectifier diodes of 100V or more for transformer secondary, high-speed diodes of 600V~1.2kV for RCD buffer circuits, and 600V diodes for PFC boosting. The reverse recovery time Trr of UFRD is also more than 20ns, which cannot meet the needs of SMPS of 1MHz~3MHz in space stations and other fields. Even if the SMPS has a hard switch of 100kHz, due to the large conduction loss and switching loss of UFRD, the case temperature is very high, and a large heat sink is required, which increases the size and weight of SMPS, which does not conform to the development trend of miniaturization and thinning. Therefore, the development of high-voltage SBDs above 100V has always been a research topic and a hot spot of concern. In recent years, SBDs have made breakthroughs, with 150V and 200V high-voltage SBDs on the market, and SBDs over 1kV made of new materials, thus injecting new vitality and vitality into their applications.

Schottky diode disadvantages:

The biggest disadvantage of Schottky diodes is that their reverse bias is low and the reverse leakage current is large, like the Schottky diode using silicon and metal as materials, its reverse bias rated withstand voltage is only up to 50V, and the reverse leakage current value is a positive temperature characteristic, which is easy to increase rapidly with the increase of temperature, and it is necessary to pay attention to its thermal runaway concerns in practical design. In order to avoid the above problems, the Schottky diode will be used in practice with a much smaller reverse bias than its rated value. However, the technology of Schottky diodes has also advanced, and the reverse bias can be rated up to 200V.