Features and Benefits

  • Complete Linear Charger Controller for 1-Cell Li-Ion Batteries
  • 1% Voltage Accuracy
  • Programmable Charge Current
  • C/10 Charge Current Detection Output
  • Programmable Charge Termination Timer
  • Space Saving 8-Pin MSOP Package
  • Automatic Sleep Mode When Input Supply is Removed (Only 7µA Battery Drain)
  • Automatic Trickle Charging of Low Voltage Cells
  • Programmable for Constant-Current-Only Mode

Product Details

The LTC1731 is a complete constant-current/constant-voltage linear charger controller for single cell lithium-ion batteries. Nickel-cadmium (NiCd) and nickel-metal-hydride (NiMH) batteries can also be charged with constant current using external termination. The external sense resistor sets the charge current with 5% accuracy. An internal resistor divider and precision reference set the final float potential with ±1% accuracy. The output float voltage is set internally to 4.1V (LTC1731-4.1) or 4.2V (LTC1731-4.2).

When the input supply is removed,the LTC1731 automatically enters a low current sleep mode, dropping the battery drain current to typically 7µA. An internal comparator detects the end-of-charge (C/10) condition while a programmable timer, using an external capacitor, sets the total charge time. Fully discharged cells are automatically trickle charged at 10% of the programmed current until cell voltage exceeds 2.457V.

The LTC1731 is available in the 8-pin MSOP and SO packages.

Float Voltage
LTC1731-4.1 4.1V
LTC1731-4.2 4.2V
LTC1731-8.2 8.2V
LTC1731-8.4 8.4V


  • Cellular Phones
  • Handheld Computers
  • Charging Docks and Cradles
  • Programmable Current Source

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.

PCN-PDN Information

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