Hysteresis-Current-Controlled Buck Converter Suitable for Li-Ion Battery Charger

Abstract

A new hysteresis-current-controlled (HCC) buck converter suitable for Li-ion battery charger is presented in this paper. The technique adopted in this charger is constant current/constant voltage dual mode, which is decided by the value of internal resistance of Li-ion battery. This technique will degrade the damage of Li-ion battery and improve the power efficiency of charger. The Li-ion battery charger is designed with 0.35 - mum CMOS DPQM processes. The simulation results show that the charger works well and confirms with theoretical analysis. The power efficiency of charger can be up to 82% under the average power of 825 mW. The chip area is only 1.71times 1.52 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .