AAT1121
1.5MHz, 250mA Step-Down Converter
General Description
The AAT1121 SwitchReg is a 1.5MHz 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 AAT1121 the ideal choice for portable
applications.
The AAT1121 delivers 250mA of load current, while
maintaining a low 30µA no load quiescent current.
The 1.5MHz switching frequency minimizes the size
of external components, while keeping switching
losses low. The AAT1121 feedback and control
delivers excellent load regulation and transient
response with a small output inductor and capacitor.
The AAT1121 is available in a Pb-free, 8-pin,
2x2mm TDFN or 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
250mA Max Output Current
Up to 96% Efficiency
30µA Typical Quiescent Current
1.5MHz 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 TDFN22-8 or STDFN22-8
Package
Temperature Range: -40°C to +85°C
Applications
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Bluetooth™ Headsets
Cellular Phones
Digital Cameras
Handheld Instruments
Portable Music Players
USB Devices
Typical Application
V
IN
AAT1121
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
250mA
GND
PGND
1121.2007.03.1.2
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ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
