Analysis and design of SC DC-DC converter for maximum efficiency

In this paper, a multiple-state step-up DC-DC converter using switched-capacitor (SC) technique for mobile back-lighting applications is analyzed. Theoretical formulas concerning the conversion ratio between input and output, power efficiency and equivalent circuit are given to estimate the circuit characteristics. To achieve maximum efficiency, the design of clock duty cycle for each state of 4-state circuit structure is presented as an illustrative case study. Based on the proposed analysis and design, the focused DC-DC converter can provide not only maximum efficiency but also wide input range. Simulation and experimental results that agree well with theoretical values are included to confirm the proposed analysis and design. © 2010 SICE.