AAT1123 Datasheet, PDF (1/20 Pages) Advanced Analogic Technologies – 1MHz Step-Down Converter

General Description
The AAT1123 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 AAT1123 the ideal choice for portable
applications.
The AAT1123 is available in either a fixed version
with internal feedback or a programmable version
with external feedback resistors. It can deliver up
to 600mA 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
AAT1123 feedback and control delivers excellent
load regulation and transient response with a small
output inductor and capacitor.
The AAT1123 is designed to maintain high efficien-
cy throughout the operating range and provides
fast turn-on time.
The AAT1123 is available in a space-saving
2.0x2.1mm SC70JW-8 package and is rated over
the -40°C to +85°C temperature range.
AAT1123
1MHz Step-Down Converter
Features
SwitchReg^™
• V_IN Range: 2.7V to 5.5V
• V_OUT Adjustable Down to 0.6V
— Fixed or Adjustable Version
• Fast Turn-On Time (100µs Typical)
• 25µA No Load Quiescent Current
• Up to 97% Efficiency
• Output Current Up to 600mA
• 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
• Cellular Phones
• Digital Cameras
• Handheld Instruments
• Microprocessor / DSP Core / IO Power
• PDAs and Handheld Computers
• USB Devices
Typical Application (Fixed Output Voltage)
V_IN
C2
4.7μF
U1
AAT1123
3 _VIN
LX ⁴
1 _EN
OUT ²
5 _{AGND PGND} 7
8 _{PGND PGND} 6
L1
4.7μH
V_O
C1
22μF
AAT1123 Efficiency
(V_OUT = 2.5V; L = 10μH)
100
90
V_IN = 3.3V
80
70
60
0.1
1
10
100
1000
Output Current (mA)
1123.2006.05.1.5
1