Design method for optimizing filter to suppress switching noise

Abstract

The patent is a design method for optimizing a filter to suppress switching noise. The method includes the steps of supplying power to a switching power supply through a line impedance stabilization network, using a purely resistive load as a load end and adding the load to the maximum output load of the switching power supply and separating common mode and differential mode noise which are produced by a switch line via a differential mode and common mode noise separator and the line impedance stabilization network. Furthermore, the differential mode noise passes a differential mode filtering network carrier board, network effect of differential mode filtering is detected by the use of an oscilloscope, output and input voltage ratio of filter network noise of the differential mode are compare, insertion loss value of the differential mode filtering network is roughly estimated, standard limit requirements are met with a minimum of differential mode filtering devices, and filter optimization is achieved. Meanwhile, common mode noise passes a common mode filtering network carrier board, network effect of common mode filtering is detected by the use of the oscilloscope, output and input voltage ratio of filter network noise of the common mode are compare, insertion loss value of the common mode filtering network is roughly estimated, standard limit requirements are met with a minimum of common mode filtering devices, and filter optimization is achieved.

Description

technical field [0001] The invention relates to the field of computer application technology, in particular to a filter optimization design method for suppressing switching noise. Background technique [0002] Compared with linear power supply, switching power supply has the characteristics of high efficiency and miniaturization, which is very in line with the needs of modern industry. It is widely used in various fields such as computer and its peripheral equipment, communication, automatic control, and household appliances; its main disadvantage compared with linear power supply is Electromagnetic interference will be generated. The main reason is that the switching power supply controls the high-speed turn-on and cut-off of the transistor through the circuit. The high-speed turn-on and turn-off of the transistor will cause changes in voltage and current. The power switch tube causes rapid changes in voltage and current during the switching process. Spike interference and ...

AI Technical Summary

Problems solved by technology

[0002] Compared with linear power supply, switching power supply has the characteristics of high efficiency and miniaturization, which is very in line with the needs of modern industry. It is widely used in various fields such as computer and its peripheral equipment, communication, automatic control, and household appliances; its main disadvantage compared with linear power supply is Electromagnetic interference will be generated. The main reason is that the switching power supply controls the high-speed turn-on and cut-off of the transistor through the circuit. The high-speed turn-on and turn-off of the transistor will cause changes in voltage and current. The power switch tube causes rapid changes in voltage and current during the switching process. Spike interference and resonance interference are generated through other components in the circuit, and these noises will affect the normal operation of the internal circuit of the system and other systems through coupling channels such as conduction and radiation.

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