Switching power supply (SMPS) is widely used due to its compact size, light weight and high efficiency. But it has its own disadvantage of producing noises, which not only affect the normal operation of the circuit, but also interfere with the neighboring electronic equipment. So how to reduce the noise of SMPS? First of all, we need know where the noise comes from, and then we can eliminate it accordingly.
The noise of switching power supply can be divided into two major categories: one is the interference formed by the internal components of SMPS, and the other is the interference caused by the external factors. There are many sources of noise, such as external interference like lightning, mechanical vibration, poor contact and so on. Besides, improper design of circuit, improper parameter selection of components, unreasonable layout and wiring will also increase the power supply noise.