Features: Programmable Charge Current Range:10mA to 150mA
No External MOSFET, Sense Resistor or Blocking Diode Required
Complete Linear Charger in ThinSOTTM Package for Single Cell/Coin Cell Lithium-Ion Batteries
Constant-Current/Constant-Voltage Operation with Thermal Regulation* to Maximize Charge Rate Without Risk of Overheating
Charges Single Cell Li-Ion Batteries Directly from USB Port
Preset 4.2V Charge Voltage with ±1% Accuracy
Charge Current Monitor Output for Gas Gauging*
Automatic Recharge
Charge Status Output Pin
C/10 Charge Termination
25A Max Supply Current in Shutdown Mode
2.9V Trickle Charge Threshold
Soft-Start Limits Inrush Current
Available in a 6-Lead Low Profile (1mm) SOT-23 PackageApplicationCharger for Li-Ion Coin Cell Batteries
Portable MP3 Players, Wireless Headsets
Bluetooth Applications
Multifunction WristwatchesSpecificationsInput Supply Voltage (VCC)....................... -0.3V to 10
PROG............................................-0.3V to VCC + 0.3V
CHRG........................................................ -0.3V to 10
BAT............................................................. -0.3V to 7
BAT Short-Circuit Duration......................... Continuous
BAT Pin Current................................................ 200mA
PROG Pin Current...............................................1.5mA
Maximum Junction Temperature..........................125
Operating Temperature Range (Note 2)..-40 to 85
Storage Temperature Range.................-65 to 125
Lead Temperature (Soldering, 10 sec).................300DescriptionThe LTC® 4054L is a complete, constant-current/constant-voltage linear charger for single cell lithium-ion batteries.
Its small size and ability to regulate low charge currents make the LTC4054L especially well-suited for portable applications using low capacity rechargeable lithium-ion coin cells. Furthermore, the LTC4054L is specifically de-signed to work within USB power specifications.
No external sense resistor of LTC4054L is needed, and no blocking di-ode is required due to the internal MOSFET architecture.
Thermal feedback regulates the charge current to eliminate thermal overdesign. The charge voltage is fixed at 4.2V, and the charge current can be programmed externally with a single resistor.The LTC4054L automatically terminates a charge cycle when the charge current drops to 1/10th the programmed value after the final float voltage is reached.
When the input supply (wall adapter or USB supply) is removed, the LTC4054L automatically enters a low cur-rent state, dropping the battery drain current to less than 2A. The LTC4054L can be put into shutdown mode, re-ducing the supply current to 25A.
Other features include charge current monitor,undervoltage lockout,automatic recharge and a status pin to indicate
charge termination and the presence of an input voltage.
LTC4054L-4.2 Data Sheet
