A 4:1 Switched Capacitor Converter With Low Flying Capacitors Voltage and High Efficiency

In this article, a 4:1 switched capacitor converter is derived. Compared with the Dickson 4:1 converter, the voltage of flying capacitors is lower, and thus, the effect of dc bias on multilayer ceramic capacitor (MLCC) is reduced. With a limited number of MLCCs, the proposed converter achieves a higher efficiency, and it is suitable for the applications with limited volume such as mobile phone fast charging. A 20-V to 5-V prototype is built with 24 X7R MLCCs in 0805 package, and its efficiency is 1.7% higher than the Dickson 4:1 and 1.1% higher than the series-parallel 4:1 at 16-A output current.