CN3781

CONSONANCE 4A, Standalone Li-ion Battery Charger IC With Automatic Charge Current Adjustment CN3781 General Descriptions: The CN3781 is a PWM switch-mode lithium ion battery charger controller for 1 cell li-ion battery in a small package using few external components. The CN3781 is specially designed for charging lithium ion batteries with constant current and constant voltage mode. In constant voltage mode, the regulation voltage can be fixed at 4.2V with ± 1% accuracy, also can be adjusted upward with an external resistor. The constant charge current is programmable with a single current sense resistor. An on-chip circuit block can automatically adjust charge current based on the output capability of input supply, so CN3781 is ideally suited for the applications powered by the supply with limited output capability, such as USB port, etc. Deeply discharged batteries are automatically trickle charged at 17.5% of the full-scale current until the cell voltage exceeds 66.5% of consta...