AAT1143
1MHz 400mA Step-Down Converter
General Description
The AAT1143 SwitchReg™ is a member of
AnalogicTech's Total Power Management IC™
(TPMIC™) product family. It is a 1MHz step-down
converter with an input voltage range of 2.7V to
5.5V and output as low as 0.6V. Its low supply cur-
rent, small size, and high switching frequency
make the AAT1143 the ideal choice for portable
applications.
The AAT1143 is available in either a fixed version
with internal feedback or a programmable version
with external feedback resistors. It can deliver
400mA of load current while maintaining a low
25µA no load quiescent current. The 1MHz switch-
ing frequency minimizes the size of external com-
ponents while keeping switching losses low. The
AAT1143 feedback and control delivers excellent
load regulation and transient response with a small
output inductor and capacitor.
The AAT1143 is designed to maintain high efficien-
cy throughout the operating range, which is critical
for portable applications.
The AAT1143 is available in a space-saving
2.0x2.1mm SC70JW-8 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
Adjustable Down to 0.6V
— Fixed or Adjustable Version
25µA No Load Quiescent Current
Up to 95% Efficiency
400mA Max Output Current
1MHz Switching Frequency
Soft Start
Over-Temperature Protection
Current Limit Protection
100% Duty Cycle Low-Dropout Operation
0.1µA Shutdown Current
SC70JW-8 Package
Temperature Range: -40°C to +85°C
Applications
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Cellular Phones
Digital Cameras
Handheld Instruments
Microprocessor / DSP Core / IO Power
PDAs and Handheld Computers
USB Devices
Typical Application (Fixed Output Voltage)
V
IN
3
1
V
O
U1
AAT1143
4
2
7
6
AAT1143 Efficiency
(V
OUT
= 2.5V; L = 4.7µH)
µ
100
L1
4.7µH
C1
4.7µF
Efficiency (%)
VIN
EN
AGND
PGND
LX
OUT
PGND
PGND
V
IN
= 3.3V
90
C2
4.7µF
5
8
80
70
60
0.1
1
10
100
1000
Output Current (mA)
1143.2005.09.1.7
1
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
