Multi-chambered planar magnetics design techniques

New planar construction alternatives for blending the various power magnetic components of switch mode power processing circuits and systems are presented. These unique approaches are based on the use of core designs with multiple winding areas and core sections which provide common flux paths for transformer and inductor operations, arranged so as to minimize magnetic interactions and core material required. Construction examples for 125-watt and 50-watt DC-to-DC switch mode converters are detailed, the latter example consisting of a four-piece three-chamber cylindrical planar core structure that houses all power magnetic functions, including input filter inductance. Planar means to control leakage inductances between inductive windings are also presented for control and reduction of AC ripple current magnitudes.