High Voltage 2 Amp Monolithic Li-Ion Battery Charger

The LT3650 is a complete monolithic single-cell Li-Ion/Polymer battery charger that operates over a 4.75V to 32V input voltage range (7.5V 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 fl oat 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.

Float Voltage

LT3650-4.1

4.1V

LT3650-4.2

4.2V

LT3650-8.2

8.2V

LT3650-8.4

8.4V

Applications

* Industrial Handheld Instruments

* 12V to 24V Automotive and Heavy Equipment

* Desktop Cradle Chargers

* Notebook Computers

* Wide Input Voltage Range: 4.75V to 32V (40V Absolute Maximum)

* Programmable Charge Current Up to 2A

* User-Selectable Termination: C/10 or Onboard Termination Timer

* Dynamic Charge Rate Programming/Soft-Start Pin

* Programmable Input Current Limit

* No VIN Blocking Diode Required

* 1MHz Fixed Frequency

* Average Current Mode Control

* 0.5% Float Voltage Accuracy