AAT2556
Battery Charger and Step-Down
Converter for Portable Applications
Pin Descriptions
Pin #
Symbol
Function
1
FB
Feedback input. This pin must be connected directly to an external resistor divider.
Nominal voltage is 0.6V.
2, 8, 10
3
GND
Ground.
EN_BUCK
Enable pin for the step-down converter. When connected to logic low, the step-down
converter is disabled and it consumes less than 1µA of current. When connected to
logic high, it resumes normal operation.
4
5
EN_BAT
ISET
Enable pin for the battery charger. When internally pulled down, the battery charger is
disabled and it consumes less than 1µA of current. When connected to logic high, it
resumes normal operation.
Charge current set point. Connect a resistor from this pin to ground. Refer to typical
curves for resistor selection.
6
7
BAT
STAT
ADP
LX
Battery charging and sensing.
Charge status input. Open drain status input.
9
Input for USB/adapter charger.
11
Output of the step-down converter. Connect the inductor to this pin. Internally, it is
connected to the drain of both high- and low-side MOSFETs.
Input voltage for the step-down converter.
12
VIN
EP
Exposed paddle (bottom): connect to ground directly beneath the package.
Pin Configuration
TDFN33-12
(Top View)
1
2
3
4
5
6
12
11
10
9
FB
GND
EN_BUCK
EN_BAT
ISET
VIN
LX
GND
ADP
GND
STAT
8
7
BAT
2
2556.2006.09.1.2
AAT [ ADVANCED ANALOG TECHNOLOGY, INC. ]
