The bq24600 is a highly integrated Li-ion or Li-polymer switch-mode battery-charge controller. It offers a constant-frequency synchronous PWM controller with high-accuracy charge current and voltage regulation, charge preconditioning, termination, and charge status monitoring, The bq24600 charges the battery in three phases: preconditioning, constant current, and constant voltage. Charge is terminated when the current reaches a minimum level. An internal charge timer provides a safety backup. The bq24600 automatically restarts the charge cycle if the battery voltage falls below an internal threshold, and enters a low-quiescent-current sleep mode when the input voltage falls below the battery voltage.