Two Phase (Reconfigurable) Inverting Switched Capacitor Converter for Micro Power Applications and Its Accurate Equivalent Resistance Calculation

This brief addresses inverting switched capacitor converter (SCC) for driving the white light emitting diodes (WLEDs). The various voltage conversion ratios (VCRs) are selected to control the WLEDs blacklights, which helps to save the battery life. The major contribution are developing maximum VCRs for power converter ICs and equivalent resistance (Req) accurate calculation which includes all conduction and ohmic losses. Furthermore, inverting SCC (ISCC) experimental results are obtained from prototype model. Accurate Req analyses validates the accuracy of proposed topology. It is designed for low voltage of 10 mV to 0.1 V and it provides the output voltage of -100 mV to -0.5 V. Finally, the novelty of accurate Req calculation in this paper is that the calculation results are verified with experimental ones, particularly, at the transition region (between slow switching limit (SSL) and fast switching limit (FSL)). On the other hand, calculation, simulation and experimental results perfectly coincide with each other. Accurate equivalent resistance calculation and average current calculation are compared and some of the recent publications providing the merits of the proposed converter are explained.