General Description

ME4057 is a complete constant-current/constant voltage

linear charger for single cell lithium-ion batteries. With a

thermally enhanced 8-PIN SOP package on the bottom

and low external component count make the ME4057

ideally suited for portable applications. Furthermore the

ME4057 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 PMOSFET

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 ME4057 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 ME4057 automatically enters a low current

state dropping the battery drain current to less than

2μA.The ME4057 can be put into shutdown mode reducing

the supply current to 55μA.

Other features include Battery temperature monitor,

under-voltage lockout, automatic recharge and two status

pins to indicate charge and charge termination.