AAT2557 AnalogicTech, AAT2557 Datasheet - Page 12

• Manufacturer Part Number: AAT2557
• Description: 500mA Battery Charger and 300mA LDO Regulator for Portable Systems
• Manufacturer: AnalogicTech

Functional Block Diagram
Functional Description
The AAT2557 is a high performance power man-
agement IC comprised of a lithium-ion/polymer
battery charger and a linear regulator. The linear
regulator is designed for high-speed turn-on, fast
transient response, good power supply ripple
rejection, and low noise.
Battery Charger
The battery charger is designed for single-cell lithi-
um-ion/polymer batteries using a constant current
and constant voltage algorithm.
12
OUTLDO
INLDO
STAT
ISET
ADP
Temperature
Protection
Constant
Current
Over-
-
The battery
Protection
Reverse Blocking
Current
Over-
Charge
Control
UVLO
LDO Regulator for Portable Systems
500mA Battery Charger and 300mA
charger operates from the adapter/USB input volt-
age range from 4V to 6.5V. The adapter/USB
charging current level can be programmed up to
500mA for rapid charging applications. A status
monitor output pin is provided to indicate the bat-
tery charge state by directly driving one external
LED. Internal device temperature and charging
state are fully monitored for fault conditions. In the
event of an over-voltage or over-temperature fail-
ure, the device will automatically shut down, pro-
tecting the charging device, control system, and
the battery under charge. Other features include
an integrated reverse blocking diode and sense
resistor.
ENLDO
Amp.
Err.
+
-
V
REF
V
REF
GND
AAT2557
EN_BAT
BYP
BAT
2557.2007.06.1.0