Cancellation of inductor winding capacitance

Abstract

An inductor device or filter such as an electromagnetic interference (EMI) filter which includes an inductor provides cancellation of parasitic capacitance of the inductor and extends high frequency performance of the inductor or filter by providing the inductor using split windings and including capacitors to couple signals corresponding to those which are passed by the equivalent parallel capacitance of the inductor to another split winding or an inductor in the ground return path. Cancellation of parasitic capacitance is provided for differential mode and common mode split windings where the split windings may be either inductively coupled or not. Forming the split windings as a bifilar winding to increase coupling coefficient further improves performance and allows cancellation (as distinct from parasitic capacitance reduction) and avoidance of resonance in circuits in which an inductor is not permitted in the ground return path.

Dependencies are inferred from the claim text.