Comparison of the characteristics of rectifier diodes

There are four types of rectifier diodes: general-purpose rectifiers, general-purpose switching, Schottky barrier diodes, and fast recovery diodes. Diodes for high withstand voltage and high current are described below, but they can be classified according to their characteristics, characteristics, and manufacturing process. At this point, the characteristics and performance are optimized for the diode's basic application conditions.

The general-purpose type is generally used for rectification, and the main purpose is to rectify the AC to DC. Bridge diodes are a combination of diodes for rectification. In addition, it is used to prevent overcurrent from flowing through when the power supply or battery is inadvertently reversed. The forward voltage VF varies depending on the operating current, and about 1V is the standard. This is the ordinary VF of a silicon PN junction diode. The reverse recovery time trr is based on the assumption that the rectification of a 50Hz/60Hz commercial power supply is not particularly fast. Switching type, as its name suggests, is mainly used for switching power supplies. The VF standard is the same as that of the universal type. Because it is intended for switching purposes, TRR is faster than that of the general-purpose type. However, the speed of Schottky barrier diodes or fast recovery diodes is not yet reached, and their switching characteristics are only positioned to be faster than general-purpose models. Schottky barrier diodes (SBDs) are not PN junctions, but rather use metals and semiconductors such as N-type silicon to form Schottky barriers. Schottky barrier diodes (SBDs) have lower VF and faster switching characteristics compared to PN junction diodes. However, it is important to note that the reverse leakage current has a large IR and can cause thermal runaway under certain conditions. The VF value is about 0.8 V even when flowing through large currents such as 10 A, and about 0.5 V if a few A currents flow through it. Therefore, it is typically used on the secondary side of DC/DC converters or AC/DC converters that are in pursuit of high efficiency. Fast recovery diodes (FRDs) are PN junction diodes, but they are high-speed diodes with significantly improved trr. In this case, the withstand voltage (reverse current VR) of the SBD is 200 V or less, but the FRD can achieve a high withstand voltage of 800 V. However, in general, the VF is higher than that of the general-purpose type, and the standard value is about 2V in the case of high-withstand voltage and high-current specifications, but in recent years, there has been an increase in the number of models with a lower VF value. Because of its high withstand voltage and high speed, it is often used in AC/DC converters and inverter circuits.