Features

• 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 V_IN Blocking Diode Required
• 1MHz Fixed Frequency
• Average Current Mode Control
• 0.5% Float Voltage Accuracy
• 5% Charge Current Accuracy
• 2.5% C/10 Detection Accuracy
• NTC Resistor Temperature Monitor
• Auto-Recharge at 97.5% Float Voltage
• Auto-Precondition at <70% Float Voltage
• Bad Battery Detection with Auto-Reset
• Binary Coded Open-Collector Status Pins
• 3mm × 3mm DFN-12 or MSOP-12 Package

Typical Application

Description

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.