A Multiple Input Multiple Output Switched Capacitor DC-DC Converter with Reduced Switch Count

Switched Capacitor (SC) Converters have drawn attention of researchers recently due to their small size and high power density, primarily due to the absence of inductors. Integration on a single chip is facilitated as there are no magnetic components. A switched capacitor dc to dc converter circuit with two voltage levels as input, which can be converted to other voltage levels in buck or boost mode offering wide output voltage is presented in this work. The proposed circuit is capable of delivering 11 different output voltage levels from two input voltage levels, which includes summation of inputs, double and half output voltage levels. The novelty presented in the circuit is it uses only 9 switches, 2 charge pump capacitors and one filter capacitor to obtain the 11 gain modes. Further, an equivalent circuit model has been developed based on the differential charge theory and the mathematical equations are analyzed to obtain the optimum duty ratio at which the gating pulses to the switches are given. PSIM simulations validate the proposed circuit confirming the expected multiple output modes of the proposed circuit. This circuit can be used to power portable electronic devices and can be a potential driver for LED circuits.