A hybrid Dickson switched-capacitor (SC) DC-DC converter is implemented using 65nm bulk CMOS process, which integrates power MOSFETs, level shifters (LSs), gate drivers (GDs) and digital controller. The wafer-level flip-chipped 4-mm2 die is co-packaged with 3D stacked passives on a fine-pitch interposer for high power density. This work combines the advantages of SC- and inductor-based converters, with high efficiency and power density for a wide and continuous conversion range between 4:1 and 15:1 from a 3 – 4.5–V input, with a peak output current of 1.53 A. Peak efficiency is 94.2 % and the peak power density is 0.24 W/mm2. This device achieves significant improvements for high-voltage step-down applications when compared to conventional SC- and inductor-based power converters. Such gains are of great practical importance for low-voltage CMOS loads powered by Li-ion batteries. The new converter also represents the first CMOS implementation of a hybrid Dickson SC converter, with innovative segmented floating GD and LS designs that are directly powered by the flying capacitors themselves. These designs save significant die area when compared to those used in bootstrap solutions.