A comparison study of low-profile power magnetics for high-frequency, high-density switching converters

The electrical and mechanical issues critical to the design of low-profile power magnetics are discussed. The disk and tube-type designs are evaluated over the frequency range of 0.5-10 MHz by an optimization process to maximize the efficiency for a given foot-print and height. The tube-type transformer is shown to have a higher power density at a lower height than the disk-type transformer, operating at the same efficiency at 1 MHz. The tube-type design allows the fabrication of transformers with heights as low as 50 mils.