PCB embedded inductor for high-frequency ZVS SEPIC converter

The volume and temperature rise of passive components, especially inductors, limit the momentum toward high power density in high-frequency power converters. To address the limitations, PCB integration of passive components should be considered with the benefit of low profile, excellent thermal characteristic and cost reduction. This paper investigates an embedded structure of inductors to further increase the power density of a low power DC-DC converter. A pair of coupling inductors have been embedded into the PCB. The detailed embedded process has been described and the characteristics of embedded inductor and design consideration are discussed. A 2MHz SEPIC converter working in ZVS turn-on with embedded inductors is built to verify the effectiveness of the embedded structure.