A low-power MPPT architecture for micro-scale photovoltaic transducers

In this paper, a maximum power point tracking (MPPT) system for indoors photovoltaic transducers is presented. The proposed system is used in conjunction with a switching DC-DC boost converter that generates a 1.2 V output for the circuits of the ultra-low-power application. The MPPT tracks different illumination intensities through changing the input impedance of the boost converter. The open circuit voltage of the photovoltaic transducer is compared with a reference voltage and the switching frequency of the boost converter is changed accordingly. The stability of the MPPT feedback system is analyzed for a wide range of illumination intensities. The proposed system has been implemented in a low-cost CMOS 130nm technology. It consumes a quiescent current less than 2.5μA and achieves an average tracking efficiency (TE) of 99%.