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BQ21040 0.8-A Single-Input Single-Cell Li-Ion Battery Charger Evaluation Module



  • 5-V input operates from either USB port or AC adapter
  • Single power output with 1% battery voltage regualtion accuracy
  • 4.2V Li-Ion and Li-Pol Charger
  • 6.6V overvoltage protection; 125 C thermal regualtion; 10 hour fixed safety timer
  • Available in small SOT-23 package

Texas Instruments  BQ21040EVM-777

The bq2404x series of devices are highly integrated Li-ion linear charger devices targeted at space-limited portable applications. The devices operate from either a USB port or AC adapter and has a single power output that charges the battery. A system load can be placed in parallel with the battery as long as the average system load does not keep the battery from charging fully during the 10 hour safety timer. The charger power stage and charge current sense functions are fully integrated. The charger function has high-accuracy current and voltage regulation loops, charge status display, and charge termination. The pre-charge current and termination current threshold are programmed via an external resistor on the bq24040. The fast charge current value is also programmable via an external resistor.