Design for Ultra-High Power Density VRM Based on Six-Phase Coupled Inductors With Small Leakage Inductances

An ultra-high power density voltage regulator module (VRM) based on six-phase inverse coupled inductor (ICI) with small leakage inductances is presented. Firstly, a six-phase ICI with very short vertical heteromorphic windings and very small leakage inductances is proposed. Secondly, a basic magnetic circuit model and an improved magnetic circuit models for the ICI are presented. Thirdly, a design solution for the ICI is presented. Finally, the ICI and its magnetic circuit models and design solution are verified with Maxwell 3D simulation and experiment, the VRM with the ICI is verified with a 6V-1V, 1MHz, 90A of prototype's manufacture, steady state and transient performance experiments, efficiency and thermal measurements. When the ICI is used to the VRM, it will have ultra-high power density (1032W/in³), very small output voltage ripple (16mV), very high transient current response speed, high efficiency and low temperature. The presented ultra-high power density VRM can be used to power high performance microprocessors.