Very High Frequency IVR for Small Portable Electronics with High-Current Multi-phase 3D Integrated Magnetics

摘要

As today’s small portable electronics (smartphones,tablets, e-readers, etc.) becomes lighter, thinner, quicker, andsmarter, the voltage regulator for the pr°Cessor is expected to beefficient, miniaturized, integrated, and placed closer to thepr°Cessor. In this paper, a concept of a very high frequency (tensof MHz) 3D integrated voltage regulator (IVR) for small portableelectronics is proposed. The magnetic characterization techniqueat tens of MHz is investigated, and the issues of and solutions forpermeability and loss measurement are demonstrated. The LTCCand NEC flake materials are characterized and compared for theIVR inductor development. Both single-phase and five-phaseintegrated inductors are designed, fabricated and experimentallytested at 20MHz, featuring a simple single-via winding structure,small size, ultra-low profile, ultra-low DCR, high currenthandlingability, air-gap-free magnetics, multi-phase integrationwithin one magnetic core, and lateral non-uniform fluxdistribution.