AAT1145_08 Datasheet, PDF (1/17 Pages) Advanced Analogic Technologies – 1.5A Step-Down Converter

SwitchReg^TM
General Description
The AAT1145 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 1.5A from single-cell Lithium-ion batteries while
still achieving over 90% efficiency during peak load con-
ditions. The AAT1145 also can run at 100% duty cycle
for low dropout operation, extending battery life in por-
table systems while light load operation provides very
low output ripple for noise sensitive applications.
The AAT1145 can supply up to 1.5A 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 AAT1145 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, 3x3mm 10-lead TDFN package and is
rated over the -40°C to +85°C temperature range.
PRODUCT DATASHEET
AAT1145
1.5A Step-Down Converter
Features
• Input Voltage Range: 2.5V to 5.5V
• Output Voltages from 0.6V to V_IN
• 1.5A Output Current
• High Efficiency: Up to 95%
• 1.2MHz Constant Switching Frequency
• Low R_DS(ON) Internal Switches: 135mΩ, 95mΩ
• 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
• Cellular Phones
• Digital Cameras
• DSP Core Supplies
• PDAs
• Portable Instruments
• Smart Phones
Typical Application
VIN 2.5V-5.5V
C1
10μF
1 _EN
2 _IN
LX ⁸
LX ⁷
3 _{AIN AAT1145-1.8 OUT} 5
6 _AGND
4 _AGND
PGND ¹⁰
PGND ⁹
L1
2.2μH
VOUT
1.8V,1.5A
C2
22μF
1145.2008.01.1.2
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