PRODUCT DATASHEET
AAT1
153
2A Step-Down Converter
General Description
The AAT1153 SwitchReg™ is a 1.2MHz constant fre-
quency current mode PWM step-down converter. It is
ideal for portable equipment requiring very high current
up to 2A from single-cell Lithium-ion batteries while still
achieving over 90% efficiency during peak load condi-
tions. The AAT1153 also can run at 100% duty cycle for
low dropout operation, extending battery life in portable
systems while light load operation provides very low
output ripple for noise sensitive applications.
The AAT1153 can supply up to 2A output load current
from a 2.5V to 5.5V input voltage and the output voltage
can be regulated as low as 0.6V. The high switching fre-
quency minimizes the size of external components while
keeping switching losses low. The internal slope compen-
sation setting allows the device to operate with smaller
inductor values to optimize size and provide efficient
operation.
The AAT1153 is available in adjustable (0.6V to V
IN
) and
fixed (1.8V) output voltage versions. The device is avail-
able in a Pb-free, 3mm x 3mm 10-lead TDFN package and
is rated over the -40°C to +85°C temperature range.
Features
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Input Voltage Range: 2.5V to 5.5V
Output Voltages from 0.6V to V
IN
2A Output Current
High Efficiency: Up to 95%
1.2MHz Constant Switching Frequency
Low R
DS(ON)
Internal Switches: 0.15Ω
Allows Use of Ceramic Capacitors
Current Mode Operation for Excellent Line and Load
Transient Response
Short-Circuit and Thermal Fault Protection
Soft Start
Low Dropout Operation: 100% Duty Cycle
Low Shutdown Current: I
SHUTDOWN
< 1μA
TDFN33-10 Package
-40°C to +85°C Temperature Range
Applications
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Cellular Phones
Digital Cameras
DSP Core Supplies
PDAs
Portable Instruments
Smart Phones
Typical Application
V
IN
2.5V-5.5V
L1
2.2μH
V
OUT
1.8V, 2A
1
2
EN
IN
AIN
LX
8
7
5
10
9
C1
22μF
3
AAT1153-1.8
LX
OUT
C2
22μF
6 AGND
4 AGND
PGND
PGND
1153.2008.02.1.2
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