High Power Density 4:1 Resonant Switched-Capacitor DC-DC Converter for PoL Applications

In recent years, resonant switched-capacitors converters (ReSCC) proved to be a valid alternative to traditional buck converters, thanks to their key features such as very high power density, high efficiency, and capability of adjusting the output voltage through quasi-resonant operation. However, since the components count increases with the conversion ratio, these advantages are usually limited to ReSCC topologies providing 2:1 nominal down-conversion. This paper presents a novel DC/DC ReSCC topology that performs a nominal 12 to 3 V (4:1) down-conversion. Thanks to the minimum number of components and the use of parasitic PCB inductors, a peak power density of 0.53
$\mathrm{W}/\text{mm}^{{2}}$
is reached at 5 A current load, while the peak efficiency is 94.4 %. A novel control system for 3-phase quasi-resonant operation is then introduced, enabling fine output voltage regulation below the 3 V nominal output voltage value.