Effect of Shielding and Component Placement in DM EMI Filters on a Power Supply's Conducted EMI

This paper considers the effect of copper shields placed between differential-mode CLC filter components and the effect of the component placement on conducted electromagnetic interference of a switch-mode power supply. The study is based on comparative measurements of a power supply conducted electromagnetic interference for different configurations of the differential-mode filter. It is shown that using printed circuit board with two metal layers and shields can improve electromagnetic interference attenuation introduced by the filter.