850kHz 700mA Synchronous
Buck DC/DC Converter
General Description
The AAT1151 SwitchReg™ is a step-down switch-
ing converter ideal for applications where high effi-
ciency is required over the full range of output load
conditions. The 2.7V to 5.5V input voltage range
makes the AAT1151 ideal for single-cell lithium-
ion/polymer battery applications. Capable of more
than 700mA with internal MOSFETs, the current-
mode controlled IC provides high efficiency using
synchronous rectification. Fully integrated compen-
sation simplifies system design and lowers external
parts count.
The device operates at a fixed 850kHz switching fre-
quency and enters Pulse Frequency Modulation
(PFM) mode for light load current to maintain high
efficiency across all load conditions.
The AAT1151 is available in Pb-free MSOP-8 and
QFN33-16 packages and is rated over the -40°C to
+85°C temperature range.
AAT1151
Features
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SwitchReg
™
V
IN
Range: 2.7V to 5.5V
Up to 95% Efficiency
High Initial Accuracy ±1%
110mΩ R
DS(ON)
Internal Switches
<1μA Shutdown Current
850kHz Switching Frequency
Fixed V
OUT
or Adjustable V
OUT
≥1.0V
Integrated Power Switches
Synchronous Rectification
Current Mode Operation
Internal Compensation
Stable with Ceramic Capacitors
PFM for Optimum Efficiency for All Load
Conditions
Internal Soft Start
Over-Temperature Protection
Current Limit Protection
MSOP-8 and QFN33-16 Packages
-40°C to +85°C Temperature Range
Applications
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Cellular Phones
Digital Cameras
MP3 Players
Notebook Computers
PDAs
USB-Powered Equipment
Wireless Notebook Adapters
Typical Application
INPUT
10μF
VP
FB
AAT1151
LX
ENABLE
100Ω
VCC
3.0μH
OUTPUT
SGND
0.1μF
PGND
2x 22μF
1151.2007.01.1.6
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ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
