Planar common mode inductor design for EMI filter

In this paper, a novel common mode inductor structure is proposed to achieve high power density for the EMI filter. For better utilization of space, planar core is adopted. In this new design, the core integrates both the CM and DM inductors. Response surface methodology is applied for better design of the inductor. Furthermore, bifilar windings are adopted for less interaction. Finally, some simulation and experimental results of this planar EMI filter are presented.