LTC4054L-4.2 Datasheet | Linear Technology

.. LTC4054L-4.2 150m A Standalone Linear Li-Ion Battery Charger in Thin SOT DESCRIPTIO The LTC®4054L is a plete, constant-current/constantvoltage linear charger for single cell lithium-ion batteries. Its small size and ability to regulate low charge currents make the LTC4054L especially well-suited for portable applications using low capacity rechargeable lithium-ion coin cells. Furthermore, the LTC4054L is specifically designed to work within USB power specifications. No external sense resistor is needed, and no blocking diode is required due to the internal MOSFET architecture. Thermal feedback regulates the charge current to eliminate thermal overdesign. The charge voltage is fixed at 4.2V, and the charge current can be programmed externally with a single resistor. The LTC4054L automatically terminates a charge cycle when the charge current drops to 1/10th the programmed value after the final float voltage is reached. When the input supply (wall adapter or USB supply) is removed, the LTC4054L automatically enters a low current state, dropping the battery drain current to less than 2µA. The LTC4054L can be put into shutdown mode, reducing the supply current to 25µA. Other Features include charge current monitor, undervoltage lockout, automatic recharge and a status pin to indicate charge termination and the presence of an input voltage. , LTC and LT are registered trademarks of Linear Technology Corporation. Thin SOT is a trademark of Linear Technology Corporation. - U.S. Patent No. 6,522,118 Features s s s s s s s s s s s s s s U APPLICATIO S s s s s Programmable Charge Current Range: 10m A to 150m A No External MOSFET, Sense Resistor or Blocking Diode Required plete Linear Charger in Thin SOTTM Package for Single Cell/Coin 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...