Power supply design circuit with high-level EMC and safety regulation performance

Abstract

The invention, which is suitable of the rail transport industry, provides a power supply design circuit with the high-level electro magnetic compatibility and safety regulation performance. The power supply design circuit comprises an input unit, an isolation filtering protection unit and an output unit, wherein the units are successively connected. The isolation filtering protection unit includes an electromagnetic anti-interference protection circuit, an electromagnetic interference filtering circuit, and an isolation circuit; the electromagnetic anti-interference protection circuit clamps and discharges a common-mode interference signal and a differential-mode interference signal that are outputted by the input unit; and the electromagnetic interference filtering circuit carries out common-mode filtering on an input signal and an output signal of the isolation circuit and carries out differential-mode filtering on the input signal of the isolation. Because of the electromagnetic anti-interference protection circuit and the isolation circuit, the input unit and the output unit are isolated a PCB board space design is carried out, so that the high isolation insulated voltage requirement can be met and the voltage-resistant property can be improved. Meanwhile, the electromagnetic interference filtering circuit filters an interference signal outputted by the input unit, thereby meeting the limit value requirements of 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. like 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 cann...

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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

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