This paper proposes a stackable multi-inductor-middle (MIM) 48V-to-1V hybrid DC–DC converter for 3D vertical power delivery, where the switching converter cells are embedded on the backside of a GPU package substrate to shorten the power path. The proposed MIM 3D hybrid architecture reduces the device voltage stress and the DC current flowing through each inductor simultaneously. In addition, we have investigated two up-scaling approaches for high-current power delivery. A hardware prototype with an area of 30 mm × 6.5 mm and a height of 4.8 mm achieves a power density of 2310W/inch3, while delivering up to 110A.
