Maximum Power Point Tracking Circuit for an Energy Harvester in 130 nm CMOS Technology

This paper presents design of a Maximum Power Point Tracking (MPPT) circuit and its functionality for tuning the maximum power transfer from an energy harvester (EH) unit. Simple and practical “Perturb and Observe” (P&O) algorithm is investigated and implemented. We describe the circuit functionality and the improvements that have been introduced to the original algorithm. The proposed MPPT design is divided into three main blocks. The output signal is being generated by the PWM or PFM block. The tracking speed has been enhanced by implementing a variable step size in the “Tracking Block”. Finally, the overall power consumption of the MPPT circuit itself is controlled by the “Power Management Block”, which manages delivering the clock signal to the rest of the circuit. The RTL code of the proposed MPPT has been created in Verilog, synthesized and placed-and-routed in a general purpose 130 nm CMOS technology.