A Ripple-Based Real-Time Built-in-Resistance Compensation for Switching Battery Charger Achieving Fast Charging

This brief describes a real-time built-in-resistance (BIR) compensation for a switching charger designed to achieve fast charging. The proposed BIR detection utilizes the ripple components of the switching charger, enabling the detection of the BIR information at every switching cycle. The proposed BIR compensation can continuously detect the BIR information, thereby allowing the battery to be charged in constant-current (CC) mode for almost the entire charging period. The proposed switching charger has been implemented in a 0.18μ m CMOS process, occupying a die area of 0.205mm2. The switching charger with the proposed BIR detection can charge in CC mode up to 98%, with CC mode charging time occupying 92.7% of the total charging time. The total charging time is reduced by 38.8% compared to conventional charging architecture. A peak efficiency of 95% is achieved.