A ripple voltage sensing MPPT circuit for ultra-low power microsystems

摘要: We propose a maximum power point tracking (MPPT) circuit for micro-scale sensor systems that measures ripple voltages in switched capacitor energy harvester. Compared to conventional current mirror type MPPT circuits, this design incurs no voltage drop and does not require high bandwidth amplifiers. Using correlated double sampling, accuracy is achieved with overhead of 5%, even at low harvested currents 1.4uA based on measured results 180nm CMOS.