An electronic device includes a magnetic assembly with a multilevel lamination or metallization structure having a core layer, dielectric layers and conductive features formed in metal layers on or between the dielectric layers in respective planes of orthogonal first and second directions and stacked along an orthogonal third direction. The conductive features include first and second patterned conductive features forming first and second windings, first and second conductive capacitor plates, and first and second conductive field plates, in which the first conductive capacitor plate is between the first conductive field plate and the core layer along the third direction and the second conductive capacitor plate is between the second conductive field plate and the core layer along the third direction.