PRODUCT DATASHEET
AAT1146
SwitchReg
TM
General Description
The AAT1146 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 AAT1146 is available in fixed voltage versions with
internal feedback and a programmable version with
external feedback resistors. It can deliver 400mA of load
current while maintaining a low 27μA no load quiescent
current. The 1.4MHz switching frequency minimizes the
size of external components while keeping switching
losses low.
The AAT1146 is designed to maintain high efficiency
throughout the operating range, which is critical for por-
table applications.
The AAT1146 is available in the Pb-free, space-saving
2.0x2.1mm SC70JW-8 and SOT23-5 packages and is
rated over the -40°C to +85°C temperature range.
Fast Transient 400mA 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
27μA No Load Quiescent Current
Up to 98% Efficiency
400mA 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
SC70JW-8 and SOT23-5 Packages
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
AAT1146
V
IN
C2
4.7µF
L1
LX
OUT
PGND
PGND
4.7µH
V
O
C1
4.7µF
VIN
EN
AGND
PGND
1146.2008.06.1.6
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