Power supply design circuit with high-level emc and safety performance

Abstract

The present invention is suitable for the rail transit industry, and provides a power supply design circuit with high-level EMC and safety performance, including an input unit, an isolation filter protection unit, and an output unit connected in sequence, and the isolation filter protection unit includes electromagnetic anti-interference The protection circuit, the electromagnetic interference filter circuit and the isolation circuit, the electromagnetic immunity protection circuit clamps and releases the common mode interference signal and the differential mode interference signal output by the input unit, and the electromagnetic interference filter circuit converts the input signal and the output signal of the isolation circuit The signal is subjected to common-mode filtering and the input signal of the isolation circuit is subjected to differential-mode filtering. The input unit is isolated from the output unit by setting the electromagnetic anti-interference protection circuit and the isolation circuit, and the PCB board spacing is designed to meet a larger isolation insulation voltage and improve the withstand voltage performance. At the same time, the electromagnetic interference filter circuit has no effect on the input unit. The output interference signal is filtered to meet the limit requirements of the radiation and conduction of the circuit.

Description

technical field [0001] The invention belongs to the field of electronic equipment, and in particular relates to a power supply design circuit with high-level EMC and safety performance. Background technique [0002] At present, more and more electronic devices are used in the rail transit industry. Due to frequent safety accidents on the railway, the EMC (Electro Magnetic Compatibility, Electromagnetic Compatibility) requirements of the rail transit industry are more stringent. Such as figure 1 As shown, it is a circuit schematic diagram of a traditional power supply circuit with safety performance design. Its input and output are not isolated, which leads to the direct conduction of the input ground and the output ground. As long as there is high voltage outside, it will directly enter the internal circuit of the device. , causing damage to the machine, and the insulation spacing during PCB wiring is not enough to meet the industry requirements, and the withstand voltage c...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the embodiment of the present invention is to provide a power supply design circuit with high-level EMC and safety performance with strong EMC immunity and withstand voltage performance, aiming to solve the problem of traditional power supply design circuits with high-level EMC and safety performance. The problem of weak EMC immunity and withstand voltage performance caused by unreasonable circuit design

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