A High Power Density Coupled Inductor Design for Multi-phase Buck Converters

With the increasing demand for miniaturization and high efficiency in modern electronic devices, particularly in 48V architecture server power supplies, the 2N-phase Buck converter has garnered significant attention due to its ability to achieve efficient conversion from 48V to 1V at high duty cycles. This paper proposes a miniaturized inductor design method suitable for coupled-inductor Buck converters, aiming to address the limitations of traditional inductors in meeting the requirements of high power density and efficiency. By modeling to determine the optimal coupling coefficient, the effective value of the inductor current is significantly reduced, thereby minimizing circuit ripple and losses. Building on this, a method for optimizing the core size and winding turns is designed, effectively improving conversion efficiency and reducing component volume. Simulation verification using Maxwell software confirms that the magnetic flux density and current density distributions align with the design expectations, validating the accuracy and reliability of the proposed method. The research results demonstrate that the proposed design method significantly enhances the performance of coupled inductors in high-efficiency, miniaturized power converters, providing theoretical support and practical guidance for further optimization and application in related fields.