A Core-Shared Inductor for Magnetic-Component Volume Reduction in a Two-Stage Low-Voltage DC–DC Converter

This paper proposes a core-shared inductor for a two-stage low-voltage DC–DC converter (LDC) system to improve power density while satisfying a wide input and output voltage range. In the proposed structure, the 4-switch buck–boost and LLC resonant inductors are integrated into a shared magnetic core assembly to reduce their combined volume. To verify the feasibility of the proposed approach, a 2-kW LDC prototype was experimentally evaluated using both the conventional separate inductors and the proposed core-shared inductor. Experimental results demonstrate that the proposed system maintains conversion efficiency comparable to that of the conventional system, with no appreciable efficiency improvement, while reducing the combined volume and mass of the 4-switch buck–boost and LLC resonant inductors by approximately 9% and 10%, respectively, compared with the conventional design. Therefore, the proposed magnetic integration method provides an effective approach to reducing the volume of magnetic components in wide-range two-stage LDC systems.