DATA SHEET
AAT2504
AdjustableThree-Channel Regulator
General Description
Features
The AAT2504 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.
The two LDOs have an input voltage range of 1.8V to
5.5V, making them well-suited for post regulating from
the step-down converter.
• 800mA Buck Converter
VIN Range: 2.7V to 5.5V
VOUT Range: 0.9V to VIN, Adjustable
High Efficiency: 95%
2MHz Switching Frequency
Synchronizable to External Clock
Internal Soft Start
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The step-down converter optimizes power efficiency
throughout the load range. Pulling the MODE/SYNC pin
high enables “PWM Only” operation, maintaining con-
stant frequency and low output ripple across the operat-
ing range. Alternatively, the converter may be synchro-
nized to an external clock to the MODE/ SYNC pin. The
step-down converter delivers up to 800mA of output cur-
rent. The switching frequency is 2MHz, minimizing the
size of external components.
• Two 300mA Linear Regulators
LDO Input Voltage Range: 1.62V to 5.5V
Low Dropout Voltage
High Output Accuracy: ±1.5%
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• Low Total Quiescent Current IQ (80ꢀA)
• Independent Enable Pins
• Over-Temperature Protection
• QFN34-20 Package
• -40°C to +85°C Temperature Range
The two LDOs (LDOA/LDOB) have independent inputs
and are capable of delivering up to 300mA each. Ultra
low input voltage on the VLDOA and VLDOB pins (down
Applications
to 1.62V) allows for efficient post-buck regulation.
A
• Cellular Phones
Power-OK (POK) function provides an open drain output
signal when LDOA is within regulation. Both LDOs feature
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.
Typical no load quiescent current is a low 80μA when the
step-down converter and LDOs are enabled.
• Digital Cameras
• Handheld Instruments
• Microprocessor/DSP Core/IO Power
• PDAs and Handheld Computers
The AAT2504 is available in a Pb-free 3x4mm QFN34-20
package and is rated over the -40°C to +85°C tempera-
ture range.
Typical Application
L
LX
FB
VOUT (Step-down)
AAT2504
VIN
R1
VIN
OUTA
OUTA
R1A
100kΩ
COUT
VLDOA
VLDOB
POK
FBA
POK
OUTB
VP
OUTB
FBB
R1B
R2B
R2A
R2
MODE/SYNC
ENA
2.2μF
2.2μF
PGND
AGND
ENB
EN
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
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202017B
• Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 19, 2013