A high-efficiency auto-reconfigurable SITIDO boost/buck regulator with input power conditioning for energy-harvesting applications

This paper demonstrates an auto-reconfigurable single-inductor triple-input dual-output (SITIDO) regulator that can obtain power from three independent sources (two energy harvesters and an internal battery) and provide dual output regulations. An input power conditioning scheme is developed to configure the converter automatically to either the energy-harvesting mode (SIDIDO/SISIDO boost configuration) or the battery-powered mode (SISISO buck configuration) based on the available power from different sources. A sub-threshold dualmode controller is also adopted to optimize the converter power efficiency over a wide load range, minimize cross regulation between different outputs, and provide the predictable output noise spectrum. Implemented in a standard 0.35-μm CMOS process, the proposed converter achieves a power efficiency of >; 66% over an output range from 0.3 mW to 33 mW with the peak power efficiency of 88%.