DESCRIPTION
The LTC®4065 is a complete constant-current/constant voltage linear charger for single-cell lithium-ion batteries. Its 2mm × 2mm DFN package and low external component count make the LTC4065 especially well-suited for portable applications. Furthermore, LTC4065 is specifically designed to work within USB power specifications.
The CHRG pin indicates when charge current has dropped to ten percent of its programmed value (C/10). An internal timer terminates charging according to battery manufacturer specifications.
No external sense resistor or blocking diode is required due to the internal MOSFET architecture. Thermal feed back regulates charge current to limit the die temperature during high power operation or high ambient temperature conditions.

FEATURES
■ Complete Linear Charger in 2mm × 2mm DFN Package
■ C/10 Charge Current Detection Output
■ Timer Termination
■ Charge Current Programmable up to 750mA with 5% Accuracy
■ No External MOSFET, Sense Resistor or Blocking Diode Required
■ Preset 4.2V Float Voltage with 0.6% Accuracy
■ Constant-Current/Constant-Voltage Operation with Thermal Feedback to Maximize Charging Rate Without Risk of Overheating
■ ACPR Pin Indicates Presence of Input Supply (LTC4065A Only)
■ Charge Current Monitor Output for Gas Gauging
■ Automatic Recharge
■ Charges Single Cell Li-Ion Batteries Directly from USB Port
■ 20µA Supply Current in Shutdown Mode
■ Soft-Start Limits Inrush Current
■ Tiny 6-Lead (2mm × 2mm) DFN Package

APPLICATIONS
■ Wireless PDAs
■ Cellular Phones
■ Portable Electronics