Controlling the parasitic parameters to improve EMI filter performance

This paper firstly reviewed the parasitic parameters in EMI filters and then introduced many methods to reduce and control these parasitic parameters. Three important methods of controlling parasitic couplings are analyzed in detail. Experiments show the filter performance is significantly improved using these three methods. A novel method is then proposed to reduce the parasitic parameters of capacitors. The experiment shows the proposed method can effectively reduce the ESL and ESR of capacitors and thus improve the EMI filter performance significantly.