20V HV Energy Harvesting Circuit with ACC/CV Mode and MPPT Control for a 5 W Solar Panel

Abstract

A HV energy harvesting circuit with ACC/CV mode and MPPT control is proposed for a 20 V/5 W solar panel. By considering the CC/CV charging process of the Liion battery and the changing maximum power point of the solar panel, the adaptive constant current (ACC) mode with PWM and MPPT control is utilized to improving the efficiency when the light source is not strong and the battery is not full. While the battery reaches full-charged, the constant voltage (CV) mode is used to prevent the damage to the Li-ion battery. The proposed design is implemented using TSMC 0.5 um UHV process. Based on the simulation results, the circuit achieves the tracking efficiency of 98% for the photocurrent from 0.1 A to 0.3 A.