AAT2120
500mA Low Noise Step-Down Converter
General Description
The AAT2120 SwitchReg is a 1.8MHz step-down
converter with an input voltage range of 2.7V to
5.5V and output as low as 0.6V. Its low supply
current, small size, and high switching frequency
make the AAT2120 the ideal choice for portable
applications.
The AAT2120 delivers up to 500mA of load current,
while maintaining a low 45µA no load quiescent cur-
rent. The 1.8MHz switching frequency minimizes
the size of external components, while keeping
switching losses low. The AAT2120 feedback and
control delivers excellent load regulation and tran-
sient response with a small output inductor and
capacitor.
The AAT2120 maintains high efficiency throughout
the load range. The AAT2120’s unique architecture
produces reduced ripple and spectral noise. Over-
temperature and short-circuit protection safeguard
the AAT2120 and system components from damage.
The AAT2120 is available in a Pb-free, 8-pin,
2x2mm STDFN package and is rated over the -40°C
to +85°C temperature range.
Features
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SwitchReg
™
V
IN
Range: 2.7V to 5.5V
V
OUT
Range: 0.6V to V
IN
Up to 500mA Output Current
Up to 96% Efficiency
Low Noise Light Load Mode
45µA Typical Quiescent Current
1.8MHz Switching Frequency
Soft-Start Control
Over-Temperature and Current Limit
Protection
100% Duty Cycle Low-Dropout Operation
<1µA Shutdown Current
Small External Components
Ultra-Small STDFN22-8 Package
Temperature Range: -40°C to +85°C
Applications
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Bluetooth
®
Headsets
Cellular Phones
Digital Cameras
Handheld Instruments
Micro Hard Disk Drive
Portable Music Players
USB Devices
Typical Application
V
IN
AAT2120
VP
VIN
C
1
4.7µF
EN
FB
LX
L1
3.0μH
R
1
118kΩ
R
2
59kΩ
C
2
4.7µF
V
O
= 1.8V
500mA
GND
PGND
2120.2007.10.1.1
1
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
