Malaysia the switching frequency of the AC-DC switching power supply module?(2)

Malaysia Choosing the switching frequency of the Marine boost power supply does not mean choosing the switching frequency of the Marine boost power supply with a good switching frequency, but the choice is suitable for your own use. Most of the current market is like this. The frequency of the AC-DC switching Marine boost power supply module is between 50K and 135K, and this frequency range can meet most applications. Let's discuss it. Some of the problems that AC-DC encounters when choosing switching frequency:

1. Why generally do not choose a switching frequency lower than 50K

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.

We know that the lower the switching frequency, the smaller the switching loss, but on the other hand, with the reduction of the switching frequency, the volume of the Marine boost power supply equipment will be reduced to the maximum, which is not conducive to miniaturization. When the switching Marine boost power supply is working, due to the switching of the switching device, the magnetic core will vibrate, and the frequency range that the human ear can hear is about 20~20000Hz. In order to avoid audible noise, we usually choose to stay away from the 20 frequency KHz.