800mA Voltage-Scaling Step-Down Converter
Pin Descriptions
Pin #
TSOPJW-12
TDFN33-12
AAT1142
Symbol
LX
Function
Connect the output inductor to this pin. The switching node is
internally connected to the drain of both high- and low-side
MOSFETs.
Main power ground return pin. Connect to the output and
input capacitor return.
Connect to ground for PFM/PWM mode and optimized effi-
ciency throughout the load range. Connect to high for low
noise PWM Only operation under all operating conditions.
Connect to an external clock for synchronization (PWM Only).
I
2
C control pin: Data input.
I
2
C control pin: Clock input.
IC enable pin. Pull high to enable the AAT1142; pull low to
disable the AAT1142. Also serves as S
2
Cwire input for pro-
grammable output voltages.
Feedback input pin. This pin is connected directly to the con-
verter output for programmable output.
Ground connection pin.
Input voltage for the converter.
Input voltage for the power switches.
Not connected.
Exposed paddle (bottom); connect to ground as closely as
possible to the device.
1
12
2
3
11
10
PGND
MODE/SYNC
4
5
6
9
8
7
SDA
SCL
EN/SET
7
8, 9, 10, 11
12
1
12
1
n/a
n/a
6
4, 5
3
1
2
EP
FB
AGND
VIN
PVIN
N/C
Pin Configuration
TSOPJW-12
(Top View)
TDFN33-12
(Top View)
LX
PGND
MODE/SYNC
SDA
SCL
EN/SET
1
2
3
4
5
6
12
11
10
9
8
7
VIN
AGND
AGND
AGND
AGND
FB
PVIN
N/C
VIN
AGND
AGND
FB
1
2
3
4
5
6
12
11
10
9
8
7
LX
PGND
MODE/SYNC
SDA
SCL
EN/SET
1. VIN and PVIN are tied together in the TSOPJW-12 package.
2
1142.2006.07.1.0
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
