DESCRIPTION

The

A4051 is a complete constant current & constant

voltage linea r charger for single cell lithium ion

batteries. Its P SOP 8 pac kage and low external

component count make the A4051 ideally suited for

portable applications. Furthermore, the A4051 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 tem perature 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

A4051

automatically terminates the charge cycle

when the charge current d rops to 1/10 th the

programmed value after the final float voltage is

reached.

When the input supply (wall adapter or USB supply)

is removed, the A4051 automatically enters a low

current state, dropping the battery drain current to

less than 0.5uA. The A405 1 can be put into shutdown

mode, reducing the supply current to 50uA.

Other features include Battery temperature monitor,

under voltage lockout, automatic recharge and two

status pins to indicate charge and charge termination.

The

A4051 is available in PS OP 8 p ackage

FEATURES

⚫ Programmable Charge Current Up to 1000mA

⚫ 1/10th of the constant charge current

⚫ No MOSFET, Sense Resistor or Blocking Diode

Required

⚫ Complete Linear Charger in P SOP 8 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

⚫ Charge Current Monitor Output for Gas Gauging

⚫ Automatic Recharge

⚫ Charge state pairs of output, no battery and fault

status display

⚫ C/10 Charge Termination

⚫ 50uA Supply Current in Shutdown

⚫ 2.9V Trickle Charge Threshold

⚫ Soft-Start Limits Inrush Current

⚫ Battery temperature monitoring function

⚫ Available in PSOP8 package APPLICATION

⚫ Cellular Telephones, PDAs, MP3 /MP4 Players

⚫ Charging Docks and Cradles

⚫ Bluetooth 、GPS Applications