On the use of current control scheme for switched-capacitor DC/DC converters

This paper presents an investigation into the use of a current control sche me (CCS) and a comparison with a classical switching scheme for switched-ca pacitor (SC) step-down dc/dc converters. With the CCS, capacitors are charg ed with near-constant current, controlled by the gate-source voltage of MOS FET's. By paralleling two SC cells, the converter input current becomes con tinuous, resulting in much reduced conducted electromagnetic interference w ith other circuits fed by the same power supply. All MOSFET's are operated for half of the switching period, in order to improve the regulation capabi lity. Static and dynamic behaviors of the converter with the CCS are predic ted and confirmed in an experimental 36-W 12-V/9-V prototype.