AAT1121
1.5MHz, 250mA Step-Down Converter
1121.2006.04.1.0 1
SwitchReg
™
General Description
The AAT1121 SwitchReg is a member of
AnalogicTech's Total Power Management IC™
(TPMIC™) product family. It 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 fre-
quency 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 package and is rated over the -40°C
to +85°C temperature range.
Features
•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 Package
• Temperature Range: -40°C to +85°C
Applications
• Bluetooth™ Headsets
• Cellular Phones
• Digital Cameras
• Handheld Instruments
• Portable Music Players
• USB Devices
Typical Application
3.0 µ H
L1
R
1
118k Ω
R
2
59k Ω
C
1
4.7µF
C
2
4.7µF
EN FB
VP
VIN
LX
PGNDGND
AAT1121
V
IN
V
O
= 1.8V 250m A