Design of a switched-capacitor-based serial DC-DC converter using clean energy power supplies

For mobile back-lighting applications, a switched-capacitor-based serial DC-DC converter using solar power supplies is proposed in this paper. Unlike conventional switched-capacitor DC-DC converters, the proposed converter pushes up the output voltage of a switched-capacitor-based circuit by the voltage of solar cells. For this reason, the proposed converter can realize not only long battery runtime but also small hardware-cost and wide input-range. Concretely, in comparison with the conventional parallel converter using 1.5× step-up SC converters, the proposed converter can achieve 20% reduction of hardware cost and 16% extension of input range. The characteristics of the proposed converter are clarified by theoretical analyses. Furthermore, SPICE simulations and experiments show the validity of circuit design, where theoretical results correspond well with simulation results.