LM3658 Datasheet, PDF (1/13 Pages) National Semiconductor (TI) – Dual Source USB/AC Li Chemistry Charger IC for Portable Applications

May 2005
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
termination voltage is controlled to within ±0.35% of 4.2V.
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 On-board Kelvin-sensing achieves ±0.35% termination
accuracy
n Maintenance mode with automatic recharge
n Thermally enhanced 3 mm x 3 mm LLP package
Applications
n Smartphones
n Digital still cameras
n PDAs
n Hard Drive and flash-based MP3 players
n USB-powered devices
Typical Application
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