Features and Benefits

Battery Charger:
  • Constant-Current/Constant-Voltage Operation with Thermal Feedback to Maximize Charge Rate Without Risk of Overheating
  • Internal 4.5 Hour Safety Timer for Termination
  • Charge Current Programmable Up to 500mA with 5% Accuracy
  • NTC Thermistor Input for Temperature Qualified Charging
  • C/10 Charge Current Detection Output
  • 5µA Supply Current in Shutdown Mode
Switching Regulator:
  • High Efficiency Synchronous Buck Converter
  • 300mA Output Current (Constant-Frequency Mode)
  • 2.7V to 4.5V Input Range (Powered from BAT Pin)
  • 0.8V to VBAT Output Range
  • MODE Pin Selects Fixed (2.25MHz) Constant-Frequency PWM Mode or Low ICC (23µA) Burst Mode® Operation
  • 2µA BAT Current in Shutdown Mode
  • 10-lead, low profile (0.75 mm) 3mm × 3mm DFN package

Product Details

The LTC4081is a complete constant-current/constantvoltage linear battery charger for a single-cell 4.2V lithium-ion/polymer battery with an integrated 300mA synchronous buck converter. A 3mm × 3mm DFN package and low external component count make the LTC4081 especially suitable for portable applications. Furthermore, the LTC4081 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 4.5-hour timer terminates the charge cycle. The fullfeatured LTC4081 battery charger also includes trickle charge, automatic recharge, soft-start (to limit inrush current) and an NTC thermistor input used to monitor battery temperature.

The LTC4081 integrates a synchronous buck converter that is powered from the BAT pin. It has an adjustable output voltage and can deliver up to 300mA of load current. The buck converter also features low current high efficiency Burst Mode operation that can be selected by the MODE pin.

The LTC4081 is available in a 10-lead, low profile (0.75mm) 3mm × 3mm DFN package.


  • Wireless Headsets
  • Bluetooth Applications
  • Portable MP3 Players
  • Multifunction Wristwatches

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.

Sample & Buy

Sample & Buy functionality exists in desktop site
Check Inventory

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 Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

Price Table Help