LM3658

Dual Source USB/AC Li Chemistry Charger IC for

Portable Applications

General Description

The LM3658 is a single chip charger IC designed for hand-

held applications. It can safely charge and maintain a single

cell Li-Ion/Polymer battery operating from an AC wall

adapter or USB power source. Input power source selection

of USB/AC is automatic. With both power sources present,

the AC power source has priority. Charge current is pro-

grammed through an external resistor when operating from

an AC wall adapter allowing charge currents from 50 mA to

1000 mA. When the battery is charged using USB power,

charge currents of 100 mA or 500 mA are pin-selectable. The

The LM3658 requires few external components and inte-

grates internal power FETs, reverse current protection and

current sensing. The internal power FETs are thermally regu-

lated to obtain the most efficient charging rate for a given

ambient temperature.

The LM3658 operates in five modes: pre-qualification mode,

constant-current mode, constant-voltage mode, top-off

mode and maintenance mode. Optimal battery management

is obtained through thermal regulation, battery temperature

measurement and multiple safety timers. The LM3658 pro-

vides two open-drain outputs for LED status indication or

connection to GPIOs.

Features

n

Integrated power FETs with thermal regulation

n

Charges from either an AC wall adapter or USB power

source with automatic source selection

n

50 mA to 1000 mA charge currents using AC wall

adapter

n

Pin-selectable USB charge currents of 100 mA or

500 mA

n

Continuous battery temperature monitoring

n

Built-in multiple safety timers

n

Charge status indication

n

Continuous over-current and temperature protection

n

Near-depleted battery pre-conditioning

n

Sleep mode with ultra low quiescent current

n

accuracy

n

Maintenance mode with automatic recharge

n

Thermally enhanced 3 mmx3mmLLP package

Applications

n

Smartphones

n

Digital still cameras

n

PDAs

n

Hard Drive and flash-based MP3 players

n

USB-powered devices

Typical Application

20128201

May 2005

© 2005 National Semiconductor Corporation

DS201282

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