AAT2552
Total Power Solution for Portable Applications
Pin Descriptions
Pin # Symbol
Function
1
EN_BAT
Enable pin for the battery charger. When connected to logic low, the battery charger is dis-
abled and consumes less than 1µA of current. When connected to logic high, the charger
operates normally (pulled down internally).
2
ISET
Charge current set point. Connect a resistor from this pin to ground. Refer to typical charac-
teristics curves for resistor selection.
3
4
AGND
FBB
Analog ground.
Feedback input for the step-down converter. This pin must be connected directly to an exter-
nal resistor divider. Nominal voltage is 0.6V.
5
6
7
8
ENB
MODE
ENA
Enable pin for the step-down converter. When connected to logic low, the step-down convert-
er is disabled and consumes less than 1µA of current. When connected to logic high, the con-
verter operates normally (pulled up internally).
Pulled down internally for automatic PWM/LL operation. Connect to logic high for forced PWM.
Drive with external clock signal to synchronize step-down converter to external clock in PWM
mode.
Enable pin for the linear regulator. When connected to logic low, the regulator is disabled and
consumes less than 1µA of current. When connected to logic high, the LDO operates normal-
ly (pulled up internally).
Feedback input for the LDO. This pin must be connected directly to an external resistor divider.
Nominal voltage is 1.24V.
FBA
9
OUTA
INA
INB
LX
Linear regulator output. Connect a 2.2µF capacitor from this pin to ground.
Linear regulator input voltage. Connect a 1µF or greater capacitor from this pin to ground.
Input voltage for the step-down converter.
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.
10
11
12
13
14
15
16
EP
PGND
BAT
ADP
Power ground.
Battery charging and sensing. Connect to positive terminal of Lithium-ion/polymer battery.
Input from USB port or AC wall adapter.
Open drain status pin for charger.
STAT
Exposed paddle (bottom): connect to ground directly beneath the package.
Pin Configuration
TDFN34-16
(Top View)
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
STAT
ADP
BAT
PGND
LX
INB
INA
EN_BAT
ISET
AGND
FBB
ENB
MODE
ENA
FBA
OUTA
2
2552.2007.04.1.0
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
