A study of integration of parasitic cancellation techniques for EMI filter design with discrete components

In this paper, effects of parasitic parameters on the electromagnetic interference (EMI) filter performance are first discussed. The parasitic cancellation techniques for both self-and mutual parasitics are then reviewed and their constraints are identified. The possibilities of integrating parasitic cancellation techniques into one EMI filter are analyzed. It is found that three parasitic cancellation techniques can be integrated into one EMI filter to improve both differential-mode and common-mode filter performances without any conflicts and compromises. Experiments are finally carried out to verify the integration of these three cancellation techniques. Index Terms--Electromagnetic interference (EMI) filter, equivalent parallel capacitance (EPC), equivalent series inductance (ESL), mutual coupling, parasitic cancellation.