Minimization of the equivalent parallel capacitance in planar magnetic EMI filters

The magnetic planar technology is nowadays an attractive solution for designing the electrical devices due to its efficiency at high frequencies and its mechanical robustness. On the other hand, the general trend of reducing the dimensions of the integrated structures one inherently leads to the increase of their structural parasitic effects. In this light, the paper proposes a new method for the minimization of the equivalent parallel capacitance (EPC) of these structures based on optimal design. The paper describes the optimization algorithm developed by the authors designed to determine the optimal placement of the structure's conductor routes that minimize the structural inter-winding capacitance. In the first part of the paper the theoretical background is presented while in the second part the optimization algorithm validation and the usage of the OptimCond package for complex planar magnetic integrated structures are outlined, followed by the final conclusions.