New Li-Ion Battery Charger Based on Charge-Pump Techniques

This paper presents a new Li-ion battery charger using charge-pump techniques. It has small chip size and simple structure. Besides, the proposed charger provides basic functions with voltage and current detecting, end-of-charge detecting and automatic charging speed control. The charger is operated in mixed method and supported from trickle/large constant-current mode to constant-voltage mode with different charging rates. This charger is implemented in TSMC 0.35 mum CMOS process with 5 V power supply. Its output voltage is over or equal to 4.2 V and maximum charging current reaches 700 mA. It has 837 mW chip power dissipation and 67.89% power efficiency and chip area is 1.455times1.348 mm
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