AAT2789 Datasheet, PDF (1/22 Pages) Advanced Analogic Technologies – Low Noise, High Frequency Dual Step-Down Converter

SystemPower^TM
PRODUCT DATASHEET
AAT2789
Low Noise, High Frequency Dual Step-Down Converter
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.
Features
• 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:
▪ Channel 1: 1700mA
▪ 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
Applications
• 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
C1
10μF
6.3V
AAT2789
TDFN34-16
VP1,2
LX1
VCC1,2
EN1 _PGND1
EN2
FB1
AGND1
LX2
PGND2
FB2
AGND2
L1
1.5μH
L2
3.3μH
V_OUT1
1.2V, 1700mA
C2
22μF
6.3V
V_OUT2
3.3V, 800mA
C3
10μF
6.3V
R3
267k
R4
59.0k
R1
59.0k
R2
59.0k
2789.2008.03.1.0
www.analogictech.com
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