General Description
The LP4054 is a complete constant-current/constant- voltage
linear charger for single cell lithium-ion batteries. Its SOT23-5
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 1μA. Other features include charge
current monitor, automatic recharge and a status pin to indicate
charge termination and the presence of an input voltage.

Applications
 Portable Media Players/MP3 players
 Cellular and Smart mobile phone
 PDA/DSC
 Bluetooth Applications

Features
 Programmable Charge Current Up to 500mA
 No MOSFET, Sense Resistor or Blocking Diode Required
 Constant-Current/Constant-Voltage Operation with
Thermal Regulation to Maximize
 Charge Rate Without Risk of Overheating
 4.2V Charge Voltage with ± 1% Accuracy
 Charge Current Monitor Output for Gas Gauging
 Automatic Recharge
 2.9V Trickle Charge Threshold
 C/10 Charge Termination
 Output OCP
 Charging OTP
 Package in SOT23-5