A Modelling and Design Approach for Push/Pull Switched Capacitor DC-DC Converters

This paper presents an extension to the switched capacitor DC-DC converter model when supplying loads stacked vertically. Stacking loads vertically drastically reduces the required size of a DC-DC converter, as it only needs to supply the mismatch current between the loads. Furthermore, when loads are perfectly matched, efficiency is only limited by the power consumption of the control loop, achieving efficiencies close to 100%. The proposed adapted model is extensively discussed, along with system level considerations regarding the required control loop. As a proof of concept, simulations of a transistor-level DC-DC converter that supplies three vertically stacked loads are shown.