Described examples include integrated magnetic circuits for LLC resonant converters (100), including an inductor cell (122-5) and multiple transformer cells (122-1) with cores (110-1) arranged in a stack structure (130). The individual transformer cells (122-1) include primary and secondary windings (PI, SI) extending around the transformer core structure (110-1), and a secondary transistor (SRI)connected in series with the secondary winding (SI). One or more windings are shaped near core stack gaps to reduce core and winding losses. The inductor cell (122-5) includes an inductor winding (LW)extending around the inductor core structure (110-5) to provide an inductor (LR), and a capacitor (CR). The inductor cell (122-5) is arranged in the stack structure (130) with the transformer cells (122-1) to magnetically couple the transformer primary windings (PI), the inductor winding (LW) and the transformer secondary windings (SI) in a single magnetic circuit to cancel cell to cell flux.