CN3705 Overview
The CN3705 is a PWM switch-mode battery charger controller for 1 or multi-cell lithium ion batteries or LiFePO4 batteries in a small package using few external ponents. The CN3705 is specially designed for charging lithium ion batteries or LiFePO4 batteries with constant current and constant voltage mode. In constant voltage mode, the regulation voltage is set by the external resistor divider. The constant charging current is programmable with a single sense resistor. Deeply discharged batteries are automatically trickle charged at 15% of the programmed constant charging current until the cell voltage exceeds 66.7% of the regulation voltage in constant voltage mode. The charge cycle is terminated once the charging current drops to a level set by an on-chip resistor and an external resistor, and a new charge cycle automatically restarts if the battery voltage falls below 91.1% of the...