Description
The LP4054 is a complete constant-current/constantvoltage
linear charger for single cell lithium-ion batteries.
Its ThinSOT package and low external component
count make the LP4054 ideally suited for portable
applications. Furthermore, the LP4054 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 limit the die temperature during high power
operation or high ambient temperature. The charge
voltage is fixed at 4.2V, and the charge current can be
programmed externally with a single resistor. The
LP4054 automatically terminates the 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 LP4054 automatically enters a low current state,
dropping the battery drain current to less than 2μA. The
LP4054 can be put into shutdown mode, reducing he
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.

Features
Programmable Charge Current Up to 800mA
No MOSFET, Sense Resistor or Blocking Diode
Required
Complete Linear Charger in ThinSOT
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
Soft-Start Limits Inrush Current
Available in 5-Lead SOT-23 Package
2.9V Trickle Charge Threshold
C/10 Charge Termination
25mA Supply Current in Shutdown
2.9V Trickle Charge Threshold

Applications
Portable Media Players/MP3 players
Cellular and Smart mobile phone
Charging Docks and Cradles
Bluetooth Applications