Method and device for reducing electromagnetic noise of switching circuit

Abstract

The invention discloses a method for reducing electromagnetic noise of a switching circuit. An integrated magnetic component is connected between a linear impedance stabilizing circuit and an optional switching power supply; an inductor and a balanced impedance element are arranged in the optional integrated magnetic component; each inductor is connected with the linear impedance stabilizing circuit or between the linear impedance stabilizing circuit and the corresponding switching power supply in series; an impedance value of each balanced impedance element is regulated by utilizing an analog switch, so that the impedance value of each balanced impedance element hops along with time; moreover, a balanced winding is connected with the balanced impedance element; the port characteristic of a coupling inductor is regulated by utilizing the balanced winding; the phase and the amplitude of a noise signal passing through the coupling inductor are regulated by utilizing the change of the port characteristic of the coupling inductor; when the phase offsets, noise source signals which are equal in frequency and are generated by the switching power supplies form phase difference; the noise source signals are offset on the linear impedance stabilizing circuit or a direct-current bus, and therefore the electromagnetic noise of the switching circuit is reduced.

Description

Technical field: [0001] The invention relates to the field of electricity, in particular to electromagnetic compatibility technology, in particular to a method and device for reducing electromagnetic noise of a switching circuit. Background technique: [0002] Switching power supply is widely used because of its advantages of high efficiency, small size and good output stability. However, due to the high frequency, high di / dt and high du / dt in the working process of the switching power supply, the problem of electromagnetic interference is very prominent, resulting in excessive electromagnetic noise of the switching circuit. [0003] In the prior art, common measures for suppressing electromagnetic noise of switching circuits mainly include methods for suppressing interference sources, filtering methods, shielding methods, methods for improving device characteristics, and adopting appropriate circuit layouts. For example, by randomly modulating the pulse width modulation fr...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a method for reducing the electromagnetic noise of the switching circuit. The method for reducing the electromagnetic noise of the switching circuit is to solve the problem that multiple switching power supplies are connected in parallel through the DC bus in the prior art and cause the bus noise signal to exceed the standard. question

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