Dual output sub-period interleaved step-up Fibonacci switched capacitor converters

Abstract

The paper proposes a new class of dual output step-up Fibonacci switched capacitor converters (SCC) and formal approach for its synthesis. The resolution of target voltages in the new SCC has been significantly increased in comparison with the previously developed single-output SCC, where the target voltages are spaced as 1/x. In the case of three flying capacitors the proposed SCC provides six different pairs of target voltages. The output current in the proposed SCC is discontinuous due to the switching between three states over a period. This operation mode is called sub-period interleaving and may help lower the output voltage ripple. The proposed SCC can be used in low-voltage energy harvesting devices and/or in VLSI systems to provide different voltages to different parts of chip. The presented results were verified experimentally.