PRODUCT DATASHEET
AAT2789
SystemPower
TM
Pin Descriptions
Pin #
1
2
3
4
5
6
7,8
9
10
11
12
13
14
15
16
EP
Low Noise, High Frequency Dual Step-Down Converter
Symbol
N/C
PGND2
LX2
VP2
VCC1
EN1
VP1
LX1
PGND1
FB1
AGND1
VCC2
EN2
FB2
AGND2
EP
Function
No connect.
Power ground pin for Channel 2 step-down converter. Connect return of Channel 2 input and output
capacitors close to this pin for best noise performance.
Channel 2 step-down converter switching pin. Connect output inductor to this pin. Inductor value is
determined by output voltage.
Input supply voltage pin for Channel 2 step-down converter. Connect a 10μF ceramic input capacitor
close to this pin or connect to VP1. Operating input voltage range is 2.7V to 5.5V.
Input supply pin for Channel 1. Must be closely decoupled.
Enable Channel 1 input pin. Active high.
Input supply voltage pin for Channel 1 step-down converter. Connect a 10μF ceramic input capacitor
close to this pin. Operating input voltage range is 2.7V to 5.5V.
Channel 1 step-down converter switching pin. Connect output inductor to this pin. Inductor value is
determined by output voltage.
Power ground pin for Channel 1 step-down converter. Connect return of Channel 1 input and output
capacitors close to this pin for best noise performance.
Feedback pin for Channel 1. Connect an external resistor divider to this pin to program the output volt-
age to the desired value.
Signal ground for Channel 1.
Input supply pin for Channel 2. Must be closely decoupled.
Enable Channel 2 input pin. Active high.
Feedback pin for Channel 2. Connect an external resistor divider to this pin to program the output volt-
age to the desired value.
Signal Ground for Channel 2.
Exposed paddle. Connect to PGND1 and PGND2 as close as possible to the device. Use properly sized
vias for thermal coupling to the ground plane. See PCB layout guidelines.
Pin Configuration
TDFN34-16
(Top View)
N/C
PGND2
LX2
VP2
VCC1
EN1
VP1
VP1
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
AGND2
FB2
EN2
VCC2
AGND1
FB1
PGND1
LX1
2
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2789.2008.03.1.0
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