A 32nA Fully Autonomous Multi-Input Single-Inductor Multi-Output Energy-Harvesting and Power-Management Platform with 1.2×105 Dynamic Range, Integrated MPPT, and Multi-Modal Cold Start-Up

Abstract

Energy harvesting and power management units (EHPMUs) are gaining popularity for self-powered Internet-of-Things (loT) applications due to their ability of extracting ambient energy and powering load circuits through a single block. Among all EHPMU architectures, the multi-input single-inductor multi-output (MISIMO) [1]–[6] has the benefits of small form factor, high efficiency, extracting energy from multi-modal energy sources, and powering different types of loads. Self-powered loT applications also require the EHPMUs to have ultra-low quiescent power, wide dynamic range, and autonomous features to support their deployment without any battery. However, previous EHPMUs either consume too much power [1]–[3] or only provide a small dynamic range [4], [5]. They also suffer from two-stage power delivery causing cascaded power loss [1], [5] and lack of essential components such as voltage references [6] for a fully deployable solution. To overcome all these challenges, in this work, we propose a fully autonomous MISIMO EHPMU platform that can extract energy from three energy harvesters with both AC and DC modalities and provide four custom voltage rails together with on-chip maximum power-point tracking (MPPT) and multi-modal cold start-up circuits. This EHPMU achieves 32nA quiescent current, 1.2x1 05 dynamic range, 3.2x energy-extraction gain for piezoelectric energy harvesting, and 80% efficiency when delivering $1\mu \mathrm{A}$ output current.