A topology of charging mode control circuit suitable for long-life Li-Ion battery charger

The digital method in which control signals are activated according to charging modes is commonly used in the Li-Ion battery charger. At transition time, spike phenomenon can occur in charging current due to asynchronous control signals leading to bad impact on performance of Li-Ion battery charger. In this paper, a design approach of charging mode control circuit is proposed to eliminate this phenomenon. Moreover, parallel current source architecture is applied to lower trickle current approximate to 210mA for Li-Ion battery's safety as well as enhance large current up to 1A for saving charging time. The Li-Ion battery charging circuit is designed based on 0.13um CMOS technology and simulated by Cadence.