Czecho the switching frequency of the AC-DC switching power supply module?(5)

The synchronous rectification technology uses field effect transistors (MOSFETs) with small on-resistance and low withstand voltage to replace ordinary rectifier diodes. Since the synchronous rectifier MOSFET has the characteristics of low on-resistance (generally only a few mΩ), small leakage current when blocking, and high switching operating frequency, it can greatly reduce the power consumption of the power rectifier part and make the working efficiency of the power system obvious. It is improved, but the realization of synchronous rectification is more complicated than diode rectification in specific applications. In the application of low voltage and high current output of switching power supply, synchronous rectification technology has a good application prospect.

At present, the power carrier is mainly used for intelligent carrier in the home, remote meter reading system, and remote street lamp control system. The use range of the carrier frequency of power lines in my country is 9KHz ~ 500KHz, and the carrier bandwidth is 4KHz. The development of power carrier is very limited due to the change of power line impedance and the interference of power line noise. In order to increase the communication distance of the power carrier, we must move away from the power switching frequency of the circuit carrier unit. The carrier frequencies currently used in China are 115KHz and 132KHz. In this case, the switching frequency is around 60KHz for the Marine boost voltage power supply.