Photovoltaic Energy Harvesting Chip With P&O Maximum Power Point Tracking Circuit and Novel Pulse-Based Multiplier

Abstract

A photovoltaic (PV) energy harvesting chip with novel multiplier-based perturb and observe (P&O) maximum power point tracking (MPPT) circuit for Internet-of-Things applications is proposed, and it can be powered by only a small PV module. The proposed P&O MPPT circuit can accurately detect the maximum power point of the PV module without using a power-hungry microcontroller or inaccurate analog multiplier. Instead, a high-accuracy pulse-based multiplier is proposed. Its input signals are analog, while its output signal is digital. Moreover, a new MPPT controller based on the proposed multiplier is also presented. The chip was fabricated using a 0.18 μm 1P6M mixed-signal CMOS process. According to the measured results, the available power from the chosen PV module is 0.1-3 mW, the maximum tracking efficiency of the proposed MPPT circuit is 99.3%, and the maximum total efficiency of the proposed harvesting chip is 94.7%.