PRODUCT DATASHEET
AAT2789
SystemPower
TM
General Description
The AAT2789 is a 2-channel synchronous step-down
converter operating from an input voltage range of 2.7V
to 5.5V, making it the ideal choice for single-cell Lithium-
ion/polymer battery powered systems or low voltage
3.3V and 5V based consumer equipment.
Channel 1 delivers up to 1700mA output current while
Channel 2 delivers up to 800mA. Both converters incor-
porate a unique low noise architecture which reduces
output ripple and spectral noise.
The AAT2789 uses a high switching frequency to mini-
mize external filter sizing. Peak current mode control
eliminates external compensation while optimizing tran-
sient performance and stability.
The AAT2789 requires a minimum of external compo-
nents to realize a high efficiency dual-output step-down
converter while minimizing solution size and footprint.
Each of the step-down regulators has an independent
input and enable pin. Externally adjustable output volt-
age is provided. Light load operating mode provides high
efficiency over the entire load range. Low quiescent cur-
rent enables excellent life for battery powered systems.
The AAT2789 is available in a 3x4mm Pb-free 16-pin
TDFN package and is rated over the -40°C to 85°C oper-
ating temperature range.
Low Noise, High Frequency Dual Step-Down Converter
Features
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V
IN
Range: 2.7V to 5.5V
Output Voltage Range: 0.6V to V
IN
Low Noise Light Load Mode
Low Ripple PWM Mode
Output Current:
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Channel 1: 1700mA
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Channel 2: 800mA
Highly Efficient Step-Down Converters
Low R
DS(ON)
Integrated Power Switches
100% Duty Cycle
High Switching Frequency
Peak Current Mode Control
Internal Compensation
Excellent Transient Response
Internal Soft Start
Fast Turn-On Time
Over-Temperature Protection
Current Limit Protection
Low Profile TDFN34-16 Package
-40°C to 85°C Temperature Range
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Applications
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Cellular and Smart Phones
Digital Cameras
Handheld Instruments
Mass Storage Systems
Microprocessor / DSP Core / IO Power
PDAs and Handheld Computers
Portable Media Players
USB Devices
Wireless Data Systems
Typical Application
V
IN
: 2.7V - 5.5V
AAT2789
TDFN34-16
LX1
VP1,2
VCC1,2
EN1
PGND1
EN2
FB1
AGND1
L2
3.3μH
LX2
L1
1.5μH
C2
22μF
6.3V
V
OUT1
1.2V, 1700mA
R1
59.0k
R2
59.0k
C1
10μF
6.3V
V
OUT2
3.3V, 800mA
C3
10μF
6.3V
R3
267k
R4
59.0k
PGND2
FB2
AGND2
2789.2008.03.1.0
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