Compact modular switched-capacitor DC/DC converters with exponential voltage gain

Abstract

A compact modular switched-capacitor DC/DC converter with exponential voltage gain, high efficiency, light weight, and bidirectional power flow, is proposed in this paper. The proposed converter is suitable for applications in high temperature environments since it does not contain magnetic element nor temperature-sensitive capacitor. With an output voltage that is 2N (N is the cell number) times the low-side voltage, the proposed converter has a considerably low component count and suffers from the lowest overall capacitor voltage stress as compared with other existing switched-capacitor converters. Besides, the proposed converter adopts a modular structure and simple control scheme, which enables it to be easily extended, through a repeated cascade of the same module, to achieve a higher voltage conversion. Moreover, since the load is charged via two complementary paths in an interleaved operation, the output voltage ripple is small, which is beneficial for high efficiency. Experimental results of an 8×-gain prototype at 5 V input and 70 W output power, are provided to validate the performance of the proposed converter. The achievable efficiency is up to 95.78% (including the driver's loss).