This part is a kind of semiconductor called ME4057.

Function of this product has 1A Lithium Ion Battery Linear Charger.

Manufacturers : Microne

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ME4057 1A Lithium Ion Battery Linear Charger ME4057 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 automaticall [ ... ]

ME4057 PDF Datasheet Download