The LT3650 is a complete monolithic 2-cell Li-Ion/Polymer battery charger that operates over a 9V to 32V input voltage range (11.5V minimum start-up voltage). The LT3650 provides a constant-current/constant-voltage charge characteristic, with maximum charge current externally programmable up to 2A, set using an external current sense resistor. A precondition feature trickle-charges a low voltage battery, and bad-battery detection provides a signal and suspends charging if a battery does not respond to preconditioning.
The LT3650 can be configured to terminate charging when charge current falls to C/10, or one-tenth the programmed maximum current. Once charging is terminated, the LT3650 enters a low current (85μA) standby mode. An auto-restart feature starts a new charging cycle if the battery voltage drops 2.5% from the float voltage, or if a new battery is inserted into a charging system.
The LT3650 contains a user-programmable internal safety timer (typically set to a three hour full cycle time). The IC can be configured to use this internal timer if a time-based termination scheme is desired in which charging can continue below C/10 until a desired time is reached.
The LT3650 is available in a low profile (0.75mm) 3mm × 3mm 12-pin DFN and 12-pin MSOP packages.