27.1 A 65nm Energy-Harvesting ULP SoC with 256kB Cortex-M0 Enabling an 89.1µW Continuous Machine Health Monitoring Wireless Self-Powered System

This paper presents a system-on-chip (SoC) that enables commercial self-powered systems (SPSs) by flexibly managing application needs, harvesting energy from multiple modalities, coordinating low-latency/high-density network communication, and optimizing power across the system. To scale to a trillion IoT nodes, devices must untether from batteries by achieving energy autonomy. A SPS must balance harvested power $(\mathrm{P}_{\mathrm{H}})$ with load power $(\mathrm{P}_{\mathrm{L}})$ to enable continuous operation, which becomes challenging in real-world harvesting conditions for applications with stringent functional needs. While this SoC can support many IoT applications, we demonstrate the SoC in a machine health monitoring (MHM) product that uses multi-modal sensors to forecast motor failure to minimize downtime.