An exponential-folds design of a charge pump styled DC/DC converter

A charge pump styled DC/DC converter utilizing the exponential-folds structure and the pumping gain increase (PCI) circuit with high voltage transfer efficiency is proposed in this paper. A PGI circuit used in the linear DC/DC converter is proposed to solve the threshold voltage problem and limitation of the diode-configured output stage so that the boosted output voltage increases more linearly versus the pumping stage number. With the exponential-folds structure, fewer voltage pump stages are needed to obtain the higher output voltage and further improve the voltage pumping gain. Especially, this design still has good efficiency with low input supply voltage such as one battery cell.