Common mode inductor, common mode inductor winding method and adapter

By using a rotationally symmetrical multi-segment winding method to wind common-mode inductors, the problem of insufficient common-mode impedance under high-frequency switching and high voltage change rate is solved, achieving effective EMI filtering and reduction of parasitic capacitance in the high-frequency band, making it suitable for miniaturized adapters.

CN116264852BActive Publication Date: 2026-03-17HUAWEI DIGITAL POWER TECH CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Filing Date
2021-10-13
Publication Date
2026-03-17

AI Technical Summary

Technical Problem

Existing common-mode inductors have insufficient common-mode impedance in high-frequency switching and high voltage change rate scenarios, making it difficult to effectively suppress electromagnetic interference. Furthermore, their size and parasitic capacitance have a significant impact, resulting in poor EMI filtering performance.

Method used

A rotationally symmetric multi-segment winding method is adopted, in which N windings are wound on a toroidal core. Each winding includes two sets of windings with symmetrical starting points and opposite winding directions. The number of layers and turns in each segment of the winding is designed to be odd or different, thereby reducing parasitic capacitance and improving common-mode impedance.

Benefits of technology

Without increasing the volume, it significantly improves the high-frequency impedance and electromagnetic interference filtering capability of common-mode inductors, reduces coil volume, and enhances EMI noise suppression.

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Abstract

The application discloses a common-mode inductor, a common-mode inductor winding method and an adapter, comprising: a ring-shaped magnetic core and N windings wound on the ring-shaped magnetic core, N being an integer greater than 2; the N windings are rotationally symmetrical along the center direction of the ring-shaped magnetic core, each winding in the N windings comprises two lead terminals, and the two lead terminals are located at the outermost layers on both sides of each winding; wherein each winding in the N windings comprises a first group of windings and a second group of windings, the starting winding point of each winding in the N windings is located between the first group of windings and the second group of windings, and the number of winding sections in the first group of windings is different from the number of winding sections in the second group of windings; each winding section in the first group of windings and the second group of windings comprises multiple layers, and each layer comprises multiple turns. The common-mode inductor provided by the application can make the common-mode inductor structure have a large enough common-mode impedance without increasing the volume, thereby solving the problem of too small impedance in a high frequency band.
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Citation Information

Patent Citations

  • Electromagnetic interference (EMI) common-code inductor of new winding method and winding method of EMI common-mode inductor

    CN107195428A

  • Common mode inductor apparatus, and related winding method and electromagnetic interference filter circuit

    CN108231342A