A micro-scale solar energy harvesting circuit with MPPT control for self-powered systems

Abstract

In this paper a micro-scale solar energy harvesting system with Maximum Power Point Tracking (MPPT) control using a miniature photovoltaic cell of which the output is less than 0.5 V is proposed. The MPPT control is implemented using linear relationship between the open-circuit voltage of a main solar cell and its Maximum Power Point (MPP) voltage such that a pilot solar cell can track the MPP of the main solar cell in real time. The proposed circuit is designed in 0.18 μm CMOS process. The designed chip area is 1370 × 900 μm including a load charge pump and pads. Measured results show that the designed system can track the MPP voltage changes with variations of light intensity. The designed circuit with MPPT control provides load with MPP voltages even though the load is heavy such that it can supply more energy when the MPPT control is applied. © 2013 Springer Science+Business Media Dordrecht.