Variable-Conversion-Ratio Switched-Capacitor-Voltage-Multiplier/Divider DC-DC Converter

An interleaved scheme of variable-conversion-ratio (VCR) multistage switched-capacitor-voltage-multiplier/divider (SCVM/SCVD) converter is proposed by combining a VCR-based phase generator and pulse-width-modulation (PWM) controller to integrate step-up and down modes in one structure for high-efficiency conversion. The power part consists of two m_c-stage SC cells (front) and two n_c-stage SC cells (rear) in series for step-up/down gain of m_c × n_c or 1/(m_c × n_c) at most. Here, VCR-based phase generator is suggested with changing the running stage number m, n and topological path to obtain a suitable gain of m × n or 1/(m × n) (m = 1, 2,..., m_c, n = 1,2,..., n_c) for improving efficiency, especially for the lower desired output. Besides, PWM is adopted to enhance output regulation as well as robustness to source/loading variation. Further, some theoretical analysis and design include: formulation, steady-state analysis, conversion ratio, efficiency, output ripple, stability, capacitance selection, and control design. Finally, the closed-loop SCVM/SCVD is simulated, and the hardware is implemented and tested. All results are illustrated to show the efficacy of this scheme.