A 90.2% peak efficiency multi-input single-inductor multi-output energy harvesting interface with double-conversion rejection technique and buck-based dual-conversion mode

This article presents a multi-input single-inductor multi-output energy-harvesting interface that extracts power from three independent sources and regulates three output voltages. The converter employs the proposed double-conversion rejection technique to reduce the double-converted power by up to 81.8% under the light-load condition and operates in various power conversion modes, including the proposed buck-based dual-conversion mode, to improve the power conversion efficiency and maximum load power. The proposed adaptive peak inductor current controller determines the inductor charging period, and the proposed digitally controlled zero-current detector detects the optimum zero-current point according to the operating mode. The proposed converter achieves a peak end-to-end efficiency of 90.2% and a maximum output power of 24 mW, indicating the improvements of approximately 7.52% and 1.85 times, respectively, compared with those of conventional buck-boost converters.