LTC4069 Standalone 750mA Li-Ion Battery Charger in 2 x 2 DFN with NTC Thermistor Input

Product Details

The LTC4069 is a complete constant-current/constant-voltage linear charger for single-cell lithium-ion batteries. The 2mm × 2mm DFN package and low external component count make the LTC4069 especially well-suited for portable applications. Furthermore, LTC4069 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 feedback regulates charge current to limit the die temperature during high power operation or high ambient temperature conditions.

When the input supply (wall adapter or USB supply) is removed, the LTC4069 automatically enters a low current state, dropping battery drain current to less than 1μA. With power applied, LTC4069 can be put into shutdown mode, reducing the supply current to less than 20μA.

The LTC4069 also includes automatic recharge, low-battery charge conditioning (trickle charging), soft-start (to limit inrush current) and an NTC thermistor input used to monitor battery temperature.

The LTC4069 is available in a tiny 6-lead, low profile (0.75mm) 2mm × 2mm DFN package.


  • Wireless PDAs
  • Cellular Phones
  • Portable Electronics

Features and Benefits

  • Complete Linear Charger in 2mm × 2mm DFN Package
  • C/10 Charge Current Detection Output
  • Timer Charge Termination
  • Charge Current Programmable Up to 750mA with 5% Accuracy
  • No External MOSFET, Sense Resistor or Blocking Diode Required
  • NTC Thermistor Input for Temperature Qualified Charging
  • Preset 4.2V Float Voltage with 0.6% Accuracy
  • Constant-Current/Constant-Voltage Operation with Thermal Feedback to Maximize Charge Rate Without Risk of Overheating
  • 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