Double-magnetic-core CM-DM-integrated (common mode-difference mode-integrated) EMI (electro-magnetic interference) filter

Abstract

The invention discloses a double-magnetic-core CM-DM-integrated EMI filter. The double-magnetic-core CM-DM-integrated EMI filter is composed of two identical closed magnetic cores and four coils, wherein the two magnetic cores are opposite to each other and arranged in a stack or horizontal mode, and between the two magnetic cores is provided an air gap; CM inductor coils are wound onto the two magnetic cores together, and DM inductor coils are wound onto the two magnetic cores respectively; the closed magnetic core can be in any shape, including the ring shape. The dotted terminal of the first DM inductor coil is connected with the dotted terminal of the first CM inductor coil, and the dotted terminal of the second DM inductor coil is connected with the undotted terminal of second CM inductor coil, so that the integration of DM inductance and CM inductance of the double-magnetic-core EMI filter can be achieved. According to the embodiment of the double-magnetic-core CM-DM-integrated EMI filter, by reasonably selecting the number of turns of the coils and the types of the magnetic cores, the integration of DM inductance and CM inductance can be achieved easily, further good filtering effects and be obtained and the size of the filter can be effectively reduced.

Description

technical field [0001] The invention relates to an EMI filter, in particular to a dual magnetic core differential common-mode integrated EMI filter. Background technique [0002] The development direction of electronic circuits is toward high frequency, integration, light miniaturization, and high power density. As an economical and reliable passive component that effectively blocks the transmission path of conducted electromagnetic interference, the EMI filter has put forward higher requirements for it in the development direction of electronic circuits. [0003] At present, most EMI filters are composed of independent differential mode inductors, common mode inductors, and differential common mode capacitors. Some differential common-mode integrated inductors use special-shaped magnetic cores, or use special magnetic sheets, magnetic strips and conventional magnetic cores to construct special magnetic circuits, or combine more than two magnetic cores, which restricts the ...

AI Technical Summary

Problems solved by technology

Some differential common-mode integrated inductors use special-shaped magnetic cores, or use special magnetic sheets, magnetic strips and conventional magnetic cores to construct special magnetic circuits, or combine more than two magnetic cores, which restricts the design versatility of integrated EMI filters. and device miniaturization

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