Integrated Magnetic Circuits for Differential-mode and Common-mode Chokes of EMI Filters

Abstract


 In this paper, two magnetic circuits to integrate common-mode (CM) and differential-mode (DM) chokes of an electromagnetic interference (EMI) filter are proposed. The DM and CM chokes are integrated by using UIU and EI ferrite core shapes. To evaluate the EMI reduction performances of proposed approaches, the conducted EMI reduction performances of proposed integrated DM and CM chokes are compared with the conventional CM choke and traditional separated DM and CM chokes. From the experimental results, it ensures the advantages of the use of proposed approaches. Although some magnetic parts are eliminated by proposed approaches, the amount of DM and CM EMI attenuation rate is comparable to the case of traditional separated DM and CM chokes, except the highest peak is located at different frequencies.