A 12-volt-input hybrid switched capacitor voltage regulator based on a modified series-parallel topology

This work presents a small form factor, 12 V to 3.7 V resonant switched-capacitor (ReSC) converter IC with feedback regulation and autotuned zero current switching. The converter uses a modified series-parallel architecture to operate with single-voltage rated devices without degrading the net V-A product. Quasi-resonant operation is used to operate with conversion ratios below the nominal 3:1 level while maintaining high efficiency. A digital controller regulates the output voltage within a preset voltage band and automatically tunes the switching frequency based on zero-current detection. The converter IC was designed in 180 nm bulk CMOS with a 5 V option for power devices. It was tested in a flipchip assembly with a 33 nH 0402 inductor to deliver up to 4.6 W at 87.5 % efficiency with a power density of 0.29 W/mm
³
.