Extraction of parasitic capacitance of integrated LC component for planar EMI filter

Aiming at predicting and analyzing the high frequency performance of EMI filter efficiently,the effect of parasitic capacitance of planar inductor must be considered.In this paper,the 2D and 3D electrostatic FE model of the integrated LC component for planar EMI filter is firstly presented respectively,through calculating the parasitic capacitance among the windings,the lumped circuit model for N-turns planar winding consisted of PCB inductor is derived,then the equivalent parallel capacitor of planar winding could be given out.By analyzing the effects of per-mittivity and fringing effect on parasitic capacitance,the calculated result is to be verified by comparison with meas-urement.The method of extraction for parasitic capacitance can be used to design the planar winding and the inte-grated LC structure.