Standalone Linear Lithium Battery Charger

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3H20N Rev. P001

EC49017

General Description

EC49017

is

a

complete

constant-current

&

constant voltage linear charger for single cell lithium-ion

and Lithium-Polymer batteries. Its SOT23 package and

low external component count make EC49017 ideally

suited for portable applications. Furthermore, the

EC49017 is specifically designed to work within USB

power specification.

At the same time, EC49017 can

also be used in the standalone lithium-ion and

Lithium-polymer battery chargers.

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 4.22V, and the charge current can be

programmed externally with a single resistor.The

EC49017 automatically terminates the charge cycle

when

the

charge

current

drops

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 EC49017 automatically enters a

low current stage, dropping the battery drain current to

less than 2uA.

The EC49017 can be put into

shutdown mode, reducing the supply current to 20uA.

Other features include charge current monitor,

undervoltage lockout, automatic recharge and a status

pin to indicate charge termination and the presence of

an input voltage. EC49017 is intentionally designed to

have slightly negative Tempco. This provides extra

protection to Lithium battery during charging.

Features



Programmable Charge Current Up to 800mA



No MOSFET, Sense Resistor or Blocking Diode

Required



Constant-Current/Constant-Voltage Operation with

Thermal Protection to Maximize Charge Rate

without Risk of Overheating



Charges Single Cell Li-ion Batteries Directly from

USB Port



Preset 4.22V Charge Voltage with ±1% Accuracy



20

μ A Supply Current in Shutdown



2.9V Trickle Charge Threshold



Soft-Start Limits Inrush Current



Available in 6-Lead SOT23 and SOP-8(Exposed

PAD) Packages



RoHS Compliant and 100% Lead Pb free

Applications



Cellular Telephones, PDA, MP3 Players



Charging Docks and Cradles



Bluetooth Applications

Pin Configuration

Application Diagram