PRODUCT DATASHEET
AAT2550178
SystemPowerTM
Total Power Solution for Portable Applications
Functional Block Diagram
Reverse Blocking
BAT
ADP
Current
Compare
ADPSET
UVLO
OTP
4.2V
Constant
Current
Charge
Control
ENBAT
CV/Pre-
Charge
STAT2
STAT1
Charge
Status
TS
Watchdog
Timer
80μA
Window
Comparator
CT
INA
FBA
Err.
Amp.
DH
DL
LXA
Logic
Voltage
Reference
Control
Logic
ENA
FBB
PGND
INB
Err.
Amp.
DH
DL
LXB
Logic
Voltage
Reference
Control
Logic
ENB
PGND
Battery Charger
Functional Description
The battery charger is designed to operate with standard
AC adapter input sources, while requiring a minimum
number of external components. It precisely regulates
charge voltage and current for single-cell lithium-ion /
polymer batteries.
The AAT2550 is a highly integrated power management
IC comprised of a battery charger and two step-down
voltage converters. The battery charger is designed for
charging single-cell lithium-ion / polymer batteries.
Featuring an integrated pass device and reverse block-
ing, it offers a constant current / constant voltage charge
algorithm with a user-programmable charge current
level. The two step-down converters have been designed
to minimize external component size and maximize effi-
ciency over the entire load range. Each converter has
independent enable and input voltage pins and can pro-
vide 600mA of load current.
The adapter charge input constant current level may be
programmed up to 1A for rapid charging applications.
The battery charger features thermal loop charge reduc-
tion. In the event of operating ambient temperatures
exceeding the power dissipation abilities of the device
package for a given constant current charge level, the
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2550.2008.02.1.3
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ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
