Total Power Solution for Portable Applications
Pin Descriptions
Pin #
1
2, 10, 12, 14
3
AAT2554
Symbol
FB
GND
ENB
Function
Feedback input. This pin must be connected directly to an external resistor divider.
Nominal voltage is 0.6V.
Ground.
Enable pin for the step-down converter. When connected to logic low, the step-down
converter is disabled and consumes less than 1µA of current. When connected to
logic high, the converter resumes normal operation.
Linear regulator input voltage. Connect a 1µF or greater capacitor from this pin to
ground.
Linear regulator output. Connect a 2.2µF capacitor from this pin to ground.
Enable pin for the battery charger. When connected to logic low, the battery charger
is disabled and consumes less than 1µA of current. When connected to logic high, the
charger resumes normal operation.
Charge current set point. Connect a resistor from this pin to ground. Refer to typical
characteristics curves for resistor selection.
Battery charging and sensing.
Charge status input. Open drain status output.
Input for USB/adapter charger.
Enable pin for the linear regulator. When connected to logic low, the regulator is dis-
abled and consumes less than 1µA of current. When connected to logic high, it
resumes normal operation.
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.
Exposed paddle (bottom): connect to ground directly beneath the package.
4
5
6
VINA
OUTA
EN_BAT
7
8
9
11
13
ISET
BAT
STAT
ADP
ENA
15
16
EP
LX
VINB
Pin Configuration
TDFN34-16
(Top View)
FB
GND
ENB
VINA
OUTA
EN_BAT
ISET
BAT
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VINB
LX
GND
ENA
GND
ADP
GND
STAT
2
2554.2007.01.1.2
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
