LTC1731-8.X - Lithium-Ion Linear Battery Charger Controller

The LTC1731-8.2/LTC1731-8.4 are complete constant-current/constant-voltage linear charger controllers for 2-cell lithium-ion (Li-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 7% accuracy. An internal resistor divider and precision reference set the final float potential with 1% accuracy. The output float voltages are set internally to 8.2V (LTC1731-8.2) or 8.4V (LTC1731-8.4).

When the input supply is removed, the LTC1731-8.2/LTC1731-8.4 automatically enter a low current sleep mode, dropping the battery drain current to typically 15µA. 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 battery voltage exceeds 4.95V.

The LTC1731-8.2/LTC1731-8.4 are available in the 8-pin MSOP and SO packages. For 1-cell Li-Ion battery charging, see the LTC1731-4.1 and LTC1731-4.2 data sheets.

Features
  • Complete Linear Charger Controller for 2-Cell Lithium-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 (15µA Battery Drain)
  • Automatic Trickle Charging of Low Voltage Cells
  • Programmable for Constant-Current-Only Mode
Typical Application

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

Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC1731EMS8-8.2#PBFMS-8E$2.20$1.75
LTC1731EMS8-8.2#TRPBFMS-8E$1.81
LTC1731EMS8-8.4#PBFMS-8E$2.20$1.75
LTC1731EMS8-8.4#TRPBFMS-8E$1.81
LTC1731ES8-8.2#PBFSO-8E$1.85$1.55
LTC1731ES8-8.2#TRPBFSO-8E$1.61
LTC1731ES8-8.4#PBFSO-8E$1.85$1.55
LTC1731ES8-8.4#TRPBFSO-8E$1.61
Datasheet
Reliability Data
Related Product
LTC1731-8.2/LTC1731-8.4 - Lithium-Ion Linear Battery Charger Controller
LTC1731-8.2 Package Drawing LTC1731-8.2
R384 Reliability Data
LTC1731-8.2 Footprints and Symbols