PRODUCT DATASHEET
AAT1140
SwitchReg
TM
General Description
The AAT1140 SwitchReg is a 1.4MHz step-down con-
verter with an input voltage range of 2.7V to 5.5V and
output voltage as low as 0.6V. It is optimized to react
quickly to a load variation.
The AAT1140 is available in fixed voltage versions with
internal feedback and a programmable version with
external feedback resistors. It can deliver 600mA of load
current while maintaining a low 35μA no load quiescent
current. The 1.4MHz switching frequency minimizes the
size of external components while keeping switching
losses low.
The AAT1140 is designed to maintain high efficiency
throughout the operating range, which is critical for por-
table applications.
The AAT1140 is available in a Pb-free SOT23-5 package
and is rated over the -40°C to +85°C temperature
range.
Fast Transient 600mA Step-Down Converter
Features
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V
IN
Range: 2.7V to 5.5V
V
OUT
Fixed or Adjustable from 0.6V to V
IN
35μA No Load Quiescent Current
Up to 98% Efficiency
600mA Max Output Current
1.4MHz Switching Frequency
120μs Soft Start
Fast Load Transient
Over-Temperature Protection
Current Limit Protection
100% Duty Cycle Low-Dropout Operation
<1μA Shutdown Current
SOT23-5 Package
Temperature Range: -40°C to +85°C
Applications
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Cellular Phones
Digital Cameras
Handheld Instruments
Microprocessor / DSP Core / IO Power
PDAs and Handheld Computers
USB Devices
Typical Application (Fixed Output Voltage)
U1
AAT1140
V
IN
C2
4.7µF
IN
EN
GND
LX
OUT
L1
4.7µH
V
OUT
C1
4.7µF
1140.2007.12.1.1
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