1.5A, 1.4MHz Step-Down Converter
General Description
The AAT1112 SwitchReg is a 1.5A step-down con-
verter with an input voltage range of 2.4V to 5.5V
and an adjustable output voltage from 0.6V to V
IN
.
The 1.4MHz switching frequency enables the use
of small external components. The small footprint
and high efficiency make the AAT1112 an ideal
choice for portable applications.
The AAT1112 delivers 1.5A maximum output current
while consuming only 42µA of no-load quiescent
current. Ultra-low R
DS(ON)
integrated MOSFETs and
100% duty cycle operation make the AAT1112 an
ideal choice for high output voltage, high current
applications which require a low dropout threshold.
The AAT1112 provides excellent transient
response and high output accuracy across the
operating range. No external compensation com-
ponents are required.
The AAT1112 is designed to maintain high efficien-
cy throughout the load range. Pulling the MODE/
SYNC pin high enables "PWM Only" mode, main-
taining constant frequency and low output ripple
across the operating range. Alternatively, the con-
verter may be synchronized to an external clock
input via the MODE/SYNC pin. Over-temperature
and short-circuit protection safeguard the AAT1112
and system components from damage.
The AAT1112 is available in a Pb-free, space-sav-
ing TDFN33-12 or 2.75x3mm TSOPJW-12 pack-
age. The product is rated over an operating tem-
perature range of -40°C to +85°C.
AAT1112
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
SwitchReg
™
1.5A Maximum Output Current
Input Voltage: 2.4V to 5.5V
Output Voltage: 0.6V to V
IN
Up to 95% Efficiency
42µA No Load Quiescent Current
No External Compensation Required
1.4MHz Switching Frequency
Synchronizable to External Clock
Optional "PWM Only" Low Noise Mode
100% Duty Cycle Low-Dropout Operation
Internal Soft Start
Over-Temperature and Current Limit
Protection
<1µA Shutdown Current
TSOPJW-12 or TDFN33-12 Package
Temperature Range: -40°C to +85°C
Applications
•
•
•
•
•
•
•
Cellular Phones
Digital Cameras
Hard Disk Drives
MP3 Players
PDAs and Handheld Computers
Portable Media Players
USB Devices
Typical Application
V
IN
VP
LX
L
1
3.3µH
V
OUT
= 3.3V
AAT1112
VIN
R
1
267kΩ
C
2
10µF
EN
MODE/SYNC
GND
FB
PGND
R
2
59kΩ
C
1
22µF
1112.2007.01.1.1
1
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
