A New DC-DC Converter Circuit with Larger Step-up/down Ratio

A novel DC-DC converter circuit is proposed in this paper. It works as a boost converter, but its step-up ratio is much larger than that of the conventional boost converter. The point is that it has two identical capacitors on the output of a boost converter, which are charged in parallel and discharged in series automatically by the on-off transition of the main switching device, thus pumping up the output voltage. The circuit is simple and has some significant features of extended output voltage, less input current ripple and output voltage ripple as compared with the conventional boost converter. Moreover, the circuit can be modified to a bi-directional one with larger step-up and step-down ratio, which would facilitate UPS applications