Equivalent parallel capacitance cancellation of integrated EMI filter using coupled components

Integrated electromagnetic interference (EMI) filter has been developed based on the low-pass filter configuration of the integrated LC hybrid structure. In this paper, the equivalent parallel capacitance (EPC) of common mode (CM) inductor is effectively cancelled only by appropriate modifying part of LC hybrid winding. Applying this method, mutual inductances between the windings together with CM capacitance could be utilized to achieve improved performance; therefore no extra components are needed in filter design. To demonstrate the general cancellation condition, the simplified equivalent circuit is firstly derived. The winding configuration is then systematically analyzed and main influence factors in implementation are also investigated. Finally, simulations and experimental results confirm the effectiveness of the proposed approach.