Mfr#:

LP4057

Brand: LowPowerSemi

600mA Standalone Linear Li-Ion Battery Charger

General Description:

The LP4057 is a complete constant-current/constant- voltage 

linear charger for single cell lithium-ion batteries. Its package 

and low external component count make the LP4057 ideally 

suited for portable applications. Furthermore, the LP4057 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 LP4057 automatically terminates the charge cycle 

when the charge current drops to 1.5/10th the programmed 

value after the final float voltage is reached. When the input 

supply (wall adapter or USB supply) is removed, the LP4057

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

Features

 Programmable Charge Current Up to 600mA

 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 

 3V Trickle Charge Threshold

 Charging OTP

 Package in SOT23-6

Applications

 Portable Media Players/MP3 players 

 Cellular and Smart mobile phone 

 PDA/DSC

Bluetooth Applications

Marking Information:

Part: LP4057B6F  

MARKING: LPS BMYWX; LPS BCYWX

PACKAGE: SOT23-6

SHIPPING: 3K/REEL

MARKING INDICATION: Y: Production year W: production week; X: Production batch.