150mA Standalone Linear
Li-Ion Battery Charger in ThinSOT
n Programmable Charge Current Range:
10mA to 150mA
n No External MOSFET, Sense Resistor or Blocking
n Complete Linear Charger in ThinSOT™ Package for
Single Cell/Coin Cell Lithium-Ion Batteries
n Constant-Current/Constant-Voltage Operation with
Thermal Regulation* to Maximize Charge Rate
without Risk of Overheating
n Charges Single Cell Li-Ion Batteries Directly from
n Preset 4.2V Charge Voltage with ±1% Accuracy
n Charge Current Monitor Output for Gas Gauging*
n Automatic Recharge
n Charge Status Output Pin
n C/10 Charge Termination
n 25µA Max Supply Current in Shutdown Mode
n 2.9V Trickle Charge Threshold
n Soft-Start Limits Inrush Current
n Available in a 5-Lead Low Profile (1mm)
n Charger for Li-Ion Coin Cell Batteries
n Portable MP3 Players, Wireless Headsets
n Bluetooth Applications
n Multifunction Wristwatches
The 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 ap-
plications using low capacity rechargeable lithium-ion coin
cells. Furthermore, the LTC4054L is specifically designed
to work within USB power specifications.
No external sense resistor is needed, and no blocking
diode 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 current
state, dropping the battery drain current to less than 2µA.
The LTC4054L can be put into shutdown mode, reducing
the supply current to 25µA.
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.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property
of their respective owners. *Protected by U.S. Patents including 6,522,118.
90mA Li-Ion Single Coin Cell Charger
4.5V TO 6.5V
VCC BAT 3
Complete Charge Cycle (130mAh Battery)
VCC = 5V
θJA = 130°C/W
10 RPROG = 1.69k
TA = 25°C
0 0.25 0.5 0.75 1.0 1.25 1.5 1.75 2.0 2.25