Eternal-thing 2.0: Analog-Trojan-resilient Ripple-less Solar Harvesting System for Sustainable IoT

Abstract

Recently, harvesting natural energy is gaining more attention than other conventional approaches for sustainable IoT. System on chip (SoC) power requirement for the internet of things (IoT) and generating higher voltages on chip is a massive challenge for on-chip peripherals and systems. In this paper, an on-chip reliable energy harvesting system (EHS) is designed for IoT with an inductor free methodology. The control section monitors the computational load and the recharging of the battery/super-capacitor. An efficient maximum power point tracking (MPPT) algorithm is also used to avoid quiescent power consumption. The reliability of the proposed EHS is improved by using an aging tolerant ring oscillator. The effect of Trojan on the performance of energy harvesting system is analyzed, and proper detection and mitigation mechanism is proposed. Finally, the proposed ripple mitigation techniques further improves the performance of the aging sensor. The proposed EHS is designed and simulated in CMOS 90nm technology. The output voltage is in the range of 3-3.55 V with an input 1-1.5 V with a power throughput of 0-22 μ W. The EHS consumes power under the ultra-low-power requirements of IoT smart nodes.