A Solar Based Power Module for Battery-Less IoT Sensors Towards Sustainable Smart Cities

This paper presents an ultra-low-power solar energy harvesting system with a power management module (SEHS-PMU) for the Internet-of-Things (IoT) applications. The voltages generated are suitable for the IoT sensors used for smart cities as well as Internet-of-Medical-Things (IoMT) based biomedical applications. The SEHS-PMU is harvesting energy from the solar cell, and it can provide regulated voltages of 3.3 V, 1.8 V, 1 V, and 0.5 V. The harvesting mechanism leads to battery-less IoT, and is safe for the humanity and environment. Charge pumps (CP) are used as a boost and buck converter, which is suitable for monolithic integration. Low drop-out regulators (LDOs) are used for regulating the loads. A digital controller controls the selection of loads as per requirement for saving the power. The SEHS-PMU is designed in CMOS 180 nm technology library.