An Energy-Efficient Fast Maximum Power Point Tracking Circuit in an 800-μW Photovoltaic Energy Harvester

An energy-efficient maximum power point tracking (MPPT) circuit with a fast-tracking time for use with 800-μW PV energy harvesters is presented in this paper. The proposed MPPT circuit uses a successive approximation register MPPT algorithm, which has a power down mode and a fast tracking time, to achieve low power consumption and energy savings. The prototype MPPT circuit, which consists of analog-based circuits, has been implemented and fabricated in a 0.35-μm BCDiMOS process. The MPPT core occupies an area of 3 mm2and consumes 4.6 μW of power. The tracking time is reduced by 69.4% and the stored energy is increased by 31.4% as compared to the conventional hill climbing-based MPPT algorithm under indoor conditions.