Document
PRODUCT DATASHEET
AAT1140
SwitchRegTM
General Description
The AAT1140 SwitchReg is a 1.4MHz step-down converter with an input voltage range of 2.7V to 5.5V and output voltage as low as 0.6V. It is optimized to react quickly to a load variation. The AAT1140 is available in fixed voltage versions with internal feedback and a programmable version with external feedback resistors. It can deliver 600mA of load current while maintaining a low 35μA no load quiescent www.DataSheet4U.com current. The 1.4MHz switching frequency minimizes the size of external components while keeping switching losses low. The AAT1140 is designed to maintain high efficiency throughout the operating range, which is critical for portable applications. The AAT1140 is available in a Pb-free SOT23-5 package and is rated over the -40°C to +85°C temperature range.
Fast Transient 600mA Step-Down Converter
Features
• • • • • • • • • • • • • • VIN Range: 2.7V to 5.5V VOUT Fixed or Adjustable from 0.6V to VIN 35μA No Load Quiescent Current Up to 98% Efficiency 600mA Max Output Current 1.4MHz Switching Frequency 120μs Soft Start Fast Load Transient Over-Temperature Protection Current Limit Protection 100% Duty Cycle Low-Dropout Operation <1μA Shutdown Current SOT23-5 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)
U1 AAT1140 VIN C2 4.7µF IN EN GND LX OUT
L1 4.7µH
VOUT
C1 4.7µF
1140.2007.12.1.1
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PRODUCT DATASHEET
AAT1140
SwitchRegTM
Pin Descriptions
Pin #
1 2 3 4 5 www.DataSheet4U.com
Fast Transient 600mA Step-Down Converter
Symbol
EN GND LX IN OUT
Function
Enable pin. Ground pin. Connect to the output and input capacitor return. Switching node. Connect the inductor to this pin. It is internally connected to the drains of both high- and low-side MOSFETs. Input supply voltage for the converter. Feedback input pin. This pin is connected either directly to the converter output or to an external resistive divider for an adjustable output.
Pin Configuration
SOT23-5 (Top View)
EN GND LX
1
5
OUT
2
3
4
IN
2
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1140.2007.12.1.1
PRODUCT DATASHEET
AAT1140
SwitchRegTM
Absolute Maximum Ratings1
Symbol
VIN VLX VOUT VEN TJ TS TLEAD www.DataSheet4U.com
Fast Transient 600mA Step-Down Converter
Description
Input Voltage to GND LX to GND OUT to GND EN to GND Operating Junction Temperature Range Storage Temperature Range Maximum Soldering Temperature (at leads, 10 sec)
Value
6.0 -0.3 to VIN + 0.3 -0.3 to VIN + 0.3 -0.3 to 6.0 -40 to 150 -65 to 150 300
Units
V V V V °C °C °C
Thermal Information
Symbol
PD θJA
Description
Maximum Power Dissipation2, 3 Thermal Resistance2
Value
667 150
Units
mW °C/W
1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than th.