SEHS: Solar Energy Harvesting System for IoT Edge Node Devices.

In IoT (internet of things) realm, sensors need an uninterrupted power supply for continuous operation. This paper presents an on-chip solar EHS (SEHS) design for IoT edge node devices. For matching the impedance between the solar cell and converter, CVM technique is adopted. The energy efficient hill-climbing algorithm (HCA) is adopted to follow the maximum power point (MPP). The control section takes care of the MPPT procedure, and computational load along with the charging of the supercapacitor. LDO (low dropout regulators) is used to generate various voltages needed by the sensors. The proposed system is capable of providing power supply to various edge node devices in IoT. The SEHS is designed in CMOS 180 nm technology. The output voltage is in the range of 1.2–3.55 V with an input of 1–1.5 V. The SEHS is consuming 25 \({\upmu }\)W of power, which is within the ultra-low-power range in IoT.