DATA SHEET
AAT2503
AdjustableThree-Channel Regulator
General Description
Features
The AAT2503 is a three-channel regulator consisting of a
step-down converter with an input voltage range of 2.7V
to 5.5V plus two low dropout (LDO) linear regulators.
• 800mA Step-Down Converter
VIN Range: 2.7V to 5.5V
VOUT Range: 0.9V to VIN
High Efficiency
2MHz Switching Frequency
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The step-down converter optimizes power efficiency
throughout the load range. Pulling the MODE/SYNC pin
high enables “PWM Only” mode, maintaining constant
frequency and low output ripple across the operating
range. Alternatively, the converter may be synchronized
to an external clock input to the MODE/SYNC pin. The
step-down converter delivers up to 800mA of output cur-
rent, while consuming 30μA of typical no load quiescent
current. The switching frequency is 2MHz, minimizing
the size of external components.
• Two 150mA Low Dropout Regulators
LDO Input Voltage Range: 1.62V to 5.5V
VOUT Range: 0.6V to VIN
High Output Accuracy: ±1.5%
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• 85μA of Total IQ
• Independent Enable Pins
• Integrated Power MOSFETs
• Over-Temperature Protection
• QFN34-20 Package
The two LDOs (LDOA/LDOB) have independent inputs
and are capable of delivering up to 150mA each. Ultra
low input voltage on the VLDOA and VLDOB pins (down
to 1.62V) allows for efficient post-buck regulation. A
Power-OK (POK) function provides an open drain output
signal when LDOA is within regulation. Both LDOs fea-
ture low quiescent current and a low dropout voltage.
The output voltages for both LDOs are adjustable to as
low as 0.6V. The linear regulators have independent
Enable pins.
• -40°C to +85°C Temperature Range
Applications
• Cellular Phones
• Digital Cameras
• Handheld Instruments
• Microprocessor/DSP Core/IO Power
• PDAs and Handheld Computers
The AAT2503 is available in a Pb-free 3 x 4mm QFN34-
20 package and is rated over the -40°C to +85°C tem-
perature range.
Typical Application
L1
LX
VOUT (Buck)
AAT2503
FB
VIN
R1
VIN
OUTA
R3
100kΩ
OUTA
R4
C2
10μF
VLDOA
VLDOB
POK
FBA
POK
OUTB
C6
VP
OUTB
FBB
R5
R8
C5
2.2μF
R7
R2
MODE/SYNC
ENA
2.2μF
PGND
AGND
ENB
EN
Skyworks Solutions, Inc.
•
Phone [781] 376-3000
•
Fax [781] 376-3100
•
sales@skyworksinc.com
•
www.skyworksinc.com
1
202016B
•
Skyworks Proprietary Information
•
Products and Product Information are Subject to Change Without Notice.
•
March 19, 2013