A low power maximum power point tracker and power management system in 0.5µm CMOS

This paper presents a low-power maximum power point tracker (MPPT) and power management system (PM) for energy harvesting devices, including micro-photovoltaic (PV) cells, integrated in a 0.5 μm 2P3M CMOS process. The MPPT utilizes the fractional open circuit method which approximates the optimal operating voltage of the PV cell as a fixed fraction of the cell's open circuit voltage. The proposed system uses an inductive boost converter with off-chip inductor and a novel charge skimming regulator (CSR) structure to simultaneously generate 1.8 V and 1.2V supplies which are stored in supercapacitors. The PM manages the system supply according to available resources. The total power consumption of the chip was measured to be 11.3 μW.