LTC4068-4.2 - Standalone Linear Li-Ion Battery Charger with Programmable Termination

The LTC®4068 is a complete constant-current/constantvoltage linear charger for single cell lithium-ion batteries. Its DFN package and low external component count make the LTC4068 ideally suited for portable applications. Furthermore, the LTC4068 is designed to work within USB power specifications.

No external sense resistor or external blocking diode are required due to the internal MOSFET architecture. Thermal feedback regulates the charge current to limit the die temperature during high power operation or high ambient temperature conditions. The charge voltage is fixed at 4.2V and the charge current is programmed with a resistor. The LTC4068 terminates the charge cycle when the charge current drops below the programmed termination threshold after the final float voltage is reached.

When the input supply (wall adapter or USB supply) is removed, the LTC4068 enters a low current state dropping the battery drain current to less than 2µA. Other features include charge current monitor, undervoltage lockout, automatic recharge and status pins to indicate charge termination and the presence of adequate input voltage.

Protected by U.S. Patents, including 6522118.

Features
  • Programmable Charge Current Up to 950mA
  • Complete Linear Charger in DFN Package
  • No MOSFET, Sense Resistor or Blocking Diode Required
  • Thermal Regulation Maximizes Charge Rate Without Risk of Overheating*
  • Charges Directly from a USB Port
  • Programmable Charge Current Termination
  • Preset 4.2V Charge Voltage with ±1% Accuracy
  • Charge Current Monitor Output for Gas Gauging*
  • Automatic Recharge
  • Charge Status Output
  • “AC Present” Output
  • 2.9V Trickle Charge Threshold (LTC4068)
  • Available Without Trickle Charge (LTC4068X)
  • Soft-Start Limits Inrush Current
  • Low Profile (3mm x 3mm x 0.75mm) DFN Package
Typical Application

Applications
  • Cellular Telephones, PDAs, MP3 Players
  • Bluetooth Applications
Packaging
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC4068EDD-4.2#PBF3x3 DFN-8E$2.41$1.70
LTC4068EDD-4.2#TRPBF3x3 DFN-8E$1.80
LTC4068XEDD-4.2#PBF3x3 DFN-8E$2.41$1.70
LTC4068XEDD-4.2#TRPBF3x3 DFN-8E$1.80
Demo Boards
Part NumberDescriptionPrice
DC766ALTC4068EDD-4.2 | 800mA Stand Alone Li-Ion Charger, Vin = 4.5V - 6.3V, Vout = 800mA Charge, 40mA TerminationContact Factory
Datasheet
Reliability Data
Related Product
LTC4068-4.2/LTC4068X-4.2 - Standalone Linear Li-Ion Battery Charger with Programmable Termination
R402 Reliability Data
R421 Reliability Data
LTC4068-4.2 Footprints and Symbols