LTC4054-4.2 - Standalone Linear Li-Ion Battery Charger with Thermal Regulation in ThinSOT


  • Programmable Charge Current Up to 800mA
  • No MOSFET, Sense Resistor or Blocking Diode Required
  • Complete Linear Charger in ThinSOT™ Package for Single 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
  • 25µA Supply Current in Shutdown
  • 2.9V Trickle Charge Threshold (LTC4054)
  • Available Without Trickle Charge (LTC4054X)
  • Soft-Start Limits Inrush Current
  • Available in 5-Lead SOT-23 Package

Typical Application

LTC4054-4.2 Typical Application
LTC4054-4.2 Typical Application


The LTC4054 is a complete constant-current / constant-voltage linear charger for single cell lithium-ion batteries. Its ThinSOT package and low external component count make the LTC4054 ideally suited for portable applications. Furthermore, the LTC4054 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 limit the die temperature during high power operation or high ambient temperature. The charge voltage is fixed at 4.2V, and the charge current can be programmed externally with a single resistor. The LTC4054 automatically terminates the 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 LTC4054 automatically enters a low current state, dropping the battery drain current to less than 2µA. The LTC4054 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.

 Max Charge CurrentTrickle Charge
LTC4054-4.2 800mA Yes
LTC4054X-4.2 800mA No
LTC4054L-4.2 150mA Yes


CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
LTC4054ES5-4.2#PBF SOT-23 S5 E 05-08-1635 Yes
LTC4054ES5-4.2#TRMPBF SOT-23 S5 E 05-08-1635 Yes
LTC4054ES5-4.2#TRPBF SOT-23 S5 E 05-08-1635 Yes

LTC4054-4.2 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
LTC4054ES5-4.2#PBF SOT-23 E $2.21 Yes
LTC4054ES5-4.2#TRMPBF SOT-23 E $2.21 $1.46 Yes
LTC4054ES5-4.2#TRPBF SOT-23 E $2.21 $1.44 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC569B LTC4054ES5-4.2 | Li-Ion Linear Battery Charger, 4.25V ≤ VIN ≤ 10V, 1-Cell @ 450mA/600mA ICHARGE $75.00
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Click here to view our complete list of demo boards


  • Cellular Telephones, PDAs, MP3 Players
  • Charging Docks and Cradles
  • Bluetooth Applications

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