DESCRIPTION
The KB 4540 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 KB4540 ideally suited for portable applications. Furthermore, the KB4540 is specifically designed to work within USB power specifications.

FEATURES
■ Programmable Charge Current Up to 800mA
■ No MOSFET, Sense Resistor or Blocking
   Diode Required
■ Complete Linear Charger in SOT 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 (KB4540)
■ Available Without Trickle Charge (KB4540X)
■ Soft-Start Limits Inrush Current
■ Available in SOT23-5 Package

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