Llc resonant converter with integrated magnetics

Abstract

Disclosed examples include integrated magnetic circuits for LLC resonant converters, including an inductor cell and multiple transformer cells with cores arranged in a stack structure. The individual transformer cells include primary and secondary windings extending around the transformer core structure, and a secondary transistor connected in series with the secondary winding. One or more windings are shaped near core stack gaps to reduce core and winding losses. The inductor cell includes an inductor winding extending around the inductor core structure to provide the inductor, and the capacitor. The inductor cell is arranged in the stack structure with the transformer cells to magnetically couple the transformer primary windings, the inductor winding and the transformer secondary windings in a single magnetic circuit to cancel cell to cell flux.