LTC4068X-4.2

U U FEATURES ■ Programmable Charge Current Up to 950mA ■ Complete Linear Charger in DFN Package ■ No MOSFET, Sense Resistor or Blocking Diode Required ■ Thermal Regulation Maximizes Charge Rate Without Risk of Overheating* ■ Charges Directly from a USB Port ■ Programmable Charge Current Termination ■ Preset 4.2V Charge Voltage with ±1% Accuracy ■ Charge Current Monitor Output for Gas Gauging* ■ Automatic Recharge ■ Charge Status Output ■ “AC Present” Output ■ 2.9V Trickle Charge Threshold (LTC4068) ■ Available Without Trickle Charge (LTC4068X) ■ Soft-Start Limits Inrush Current ■ Low Profile (3mm × 3mm × 0.75mm) DFN Package U APPLICATIO S ■ Cellular Telephones, PDAs, MP3 Players ■ Bluetooth Applications LTC4068-4.2/LTC4068X-4.2 Standalone Linear Li-Ion Battery Charger with Programmable Termination DESCRIPTIO The LTC®4068 is a complete constant-current/constantvoltage linear charger for single cell lithium-ion batteries. Its DFN package and low external component count make the LTC4068 ideally suited for portable applications. Furthermore, the LTC4068 is designed to work within USB power specifications. No external sense resistor or external blocking diode are required due to the internal MOSFET architecture. Thermal feedback regulates the charge current to limit the die temperature during high power operation or high ambient temperature conditions. The charge voltage is fixed at 4.2V and the charge current is programmed with a resistor. The LTC4068 terminates the charge cyc...