A Fast and Compact Charger for an Li-Ion Battery Using Successive Built-In Resistance Detection

Abstract

In this brief, a successive built-in resistance (BIR) detection, which operates in the constant average current mode, is proposed to achieve fast charging of a lithium-ion (Li-ion) battery by accurately compensating for the voltage across the BIR. In addition, a low-dropout regulator-based structure is adopted to implement a compact-sized battery charger without using any extra external components. The proposed battery charger is fabricated using a 0.13-mu m BCD process technology with 6-V high-voltage CMOS devices, and its measurement result shows that the overall charging time is reduced by 0.5 h with a 750-mAh Li-ion battery.