An 83.4% Peak Efficiency Single-Inductor Multiple-Output Based Adaptive Gate Biasing DC-DC Converter for Thermoelectric Energy Harvesting

This paper presents a 100 mV input, 500 mV output single-inductor multiple-output (SIMO) based step-up dc-dc converter with adaptive gate biasing (AGB) technique implemented in 0.18 μm CMOS technology for thermoelectric energy harvesting. The proposed AGB technique and near-threshold voltage (near- VTH) energy redistribution control (ERC) ensure high conversion efficiency over a wide range of load currents. The proposed method automatically reduces conduction and switching losses of power MOSFETs without the need for auxiliary power converters or additional off-chip inductors. The AGB technique reduces conduction and switching losses under heavy-load and light-load conditions, respectively. The experimental results show that the efficiency of the proposed converter is enhanced by 25.5% and 18% at output load currents of 1500 μA and 50 μA, respectively. The proposed step-up dc-dc converter achieves the lowest output voltage and provides the highest conversion efficiency of 83.4% to date in standard CMOS process for thermoelectric energy harvesting.