A High-Efficiency Magnetic Component With Superior Caloric Performance for Low-Profile High-Density Power Conversion

This paper describes a magnetic component structure that features both low profile and the ability to achieve very high power and energy densities. A key characteristic which enables reaching both of these objectives is the incorporation of a foil winding with a high packing density and a unique shape factor, which enhances thermal and electromagnetic performances simultaneously. Although implementation of foil windings is common practice in magnetic component design, vertically wound foils to achieve low profile is not. Three prototype inductors are compared to a conventional litz-wound E-core inductor. Power dissipation and temperatures are measured in several different experimental procedures. At 140 kHz a power density of 1.8 kVA/in/sup 3/ was achieved for a measured efficiency of 99.5% and a steady-state hot spot temperature rise above the ambient of only 55/spl deg/C.