Development of a multistage current-controlled switched-capacitor step-down DC/DC converter with continuous input current

This paper presents the design and analysis of a low-profile multistage cur rent-controlled switched-capacitor (SC) step-down dc/dc converter, The conv erter not only exhibits all advantages of classical Se: converters, but als o features good regulation capability and continuous input current waveform , resulting in low conducted electromagnetic interference with the supply n etwork, The concept of energy transfer is achieved by paralleling the input and output of two step-down converter cells and operating them in antiphas e, The voltage conversion ratio is determined by controlling the charging t rajectories of the capacitors in each cell. As the circuit is unnecessary t o use any inductive elements, possibilities of integrated circuit fabricati on and high power density are promising. By applying the state-space averag ing technique, a third-order state-space model for an n-stage converter is derived, Static and small-signal dynamic behaviors of the com:el ter are in vestigated. A 70-W 48-V/12 V converter is implemented. Analytical predictio ns are verified with experimental measurements.