The high-power rectifier power supply requires the rectifier to have large current capacity, high breakdown voltage, and good heat dissipation performance. However, this device has a large junction area and large junction capacitance, so the operating frequency is very low, generally below tens of kilohertz. The silicon material has a large band gap and good thermal conductivity, which is suitable for making high-power rectifier devices. A high-voltage silicon stack is often used in high-voltage rectifier devices. It is composed of multiple rectifier device cores in series. Its reverse withstand voltage is determined by the withstand voltage of the core and the number of series-connected cores. The maximum withstand voltage can reach hundreds of thousands. Volt. If the high-frequency rectifier circuit is used at a very high frequency, when the cycle of the AC voltage is equivalent to the recovery time from the on-state to the off-state of the rectifier, the rectifier no longer rectifies the high-frequency voltage. In order to meet the needs of high-frequency operation, the method of doping gold is usually used in the silicon rectifier to shorten the life of the injected minority carriers, thereby achieving the purpose of reducing the recovery time.
In order to reduce the possibility of device damage due to overvoltage breakdown and improve the reliability of the rectifier device, a silicon avalanche rectifier can be used. In this kind of device, when the reverse voltage exceeds the allowable peak value, uniform avalanche breakdown occurs across the entire PN junction. The device can work under high voltage and high current, so it can withstand considerable reverse surge power. When manufacturing this kind of device, it is required to have few material defects, uniform resistivity and smooth junction surface. The exposed junction area should also be properly protected to avoid surface breakdown. The selenium rectifier has a large anti-overload capacity and a strong ability to withstand reverse surge power.
