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3-Channel Regulator. AAT2504 Datasheet

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3-Channel Regulator. AAT2504 Datasheet







AAT2504 Regulator. Datasheet pdf. Equivalent




AAT2504 Regulator. Datasheet pdf. Equivalent





Part

AAT2504

Description

Adjustable 3-Channel Regulator

Manufacture

AAT

Datasheet
Download AAT2504 Datasheet


AAT AAT2504

AAT2504; www.DataSheet4U.com AAT2504 Adjustable 3-Channel Regulator General Description The AAT2504 is a three-channel regulat or 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 t hem well-suited for post regulating fro m the step-down co.


AAT AAT2504

nverter. The step-down converter optimiz es power efficiency throughout the load range. Pulling the MODE/SYNC pin high enables "PWM Only" operation, maintaini ng constant frequency and low output ri pple across the operating range. Altern atively, the converter may be synchroni zed to an external clock to the MODE/ S YNC pin. The step-down converter delive rs up to 800mA of .


AAT AAT2504

output current. The switching frequency is 2MHz, minimizing the size of externa l components. The two LDOs (LDOA/LDOB) have independent inputs and are capable of delivering up to 300mA each. A Powe r-OK (POK) function provides an open dr ain output signal when LDOA is within r egulation. Both LDOs feature low quiesc ent current and a low dropout voltage. The output voltage.



Part

AAT2504

Description

Adjustable 3-Channel Regulator

Manufacture

AAT

Datasheet
Download AAT2504 Datasheet




 AAT2504
www.DataSheet4U.com
General Description
The AAT2504 is a three-channel regulator consist-
ing 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 volt-
age range of 1.8V to 5.5V, making them well-suited
for post regulating from the step-down converter.
The step-down converter optimizes power efficiency
throughout the load range. Pulling the MODE/SYNC
pin high enables "PWM Only" operation, maintaining
constant frequency and low output ripple across the
operating range. Alternatively, the converter may be
synchronized to an external clock to the MODE/
SYNC pin. The step-down converter delivers up to
800mA of output current. The switching frequency is
2MHz, minimizing the size of external components.
The two LDOs (LDOA/LDOB) have independent
inputs and are capable of delivering up to 300mA
each. A 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 regula-
tors have independent Enable pins. Typical no load
quiescent current is a low 80µA when the step-
down converter and LDOs are enabled.
The AAT2504 is available in a Pb-free 3x4mm
QFN34-20 package and is rated over the -40°C to
+85°C temperature range.
Typical Application
AAT2504
Adjustable 3-Channel Regulator
Features
SystemPower
• 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
• Two 300mA Linear Regulators
— VIN Range: 1.8V to 5.5V
— Low Dropout Voltage
— High Output Accuracy: ±1.5%
• Low Total Quiescent Current IQ (80μA)
• Independent Enable Pins
• Over-Temperature Protection
• QFN34-20 Package
• -40°C to +85°C Temperature Range
Applications
• Cellular Phones
• Digital Cameras
• Handheld Instruments
• Microprocessor/DSP Core/IO Power
• PDAs and Handheld Computers
VIN
MODE/SYNC
ENA
ENB
EN
LX
AAT2504 FB
L
VIN
VLDOA
VLDOB
VP
OUTA
POK
FBA
OUTB
FBB
PGND
AGND
100kΩ
POK
OUTB
R1B
2.2μF
R2B
R1A
R2A
OUTA
2.2μF
VOUT (Step-down)
R1
COUT
R2
2504.2007.06.1.0
1





 AAT2504
AAT2504
Adjustable 3-Channel Regulator
Pin Descriptions
Pin #
1
Symbol
FBB
2 ENA
3 ENB
4 MODE/SYNC
5
6
7
8, 9
10
11, 12
13
14
15
16
17
18
19
20
EP
FB
AGND
PGND
LX
VP
N/C
VIN
EN
POK
FBA
OUTA
VLDOA
VLDOB
OUTB
Function
Feedback input pin for LDOB. This pin is used to regulate the output of LDOB to the desired
value via an external resistor divider.
Enable pin for LDOA. Active high.
Enable pin for LDOB. Active high.
PWM operation and oscillator synchronization pin. Connect to ground for PWM/Light Load
operation and optimized efficiency throughout the load range. Connect high for low noise
PWM operation under all operating conditions. When connected to an external clock, the
internal oscillator is disabled and the step-down converter is synchronized to an external
clock applied to this pin (PWM only).
Feedback input pin for the step-down converter. This pin is used to see the output of the
converter to regulate to the desired value via an external resistor divider.
Ground connection pin.
Main power ground return pin for the step-down converter. Connect to the output and input
capacitor return.
Connect inductor to this pin. Switching node internally connected to the drain of both high-
and low-side MOSFETs.
Input supply voltage for the converter. Must be closely decoupled.
Not connected.
Bias supply. Supply power for the internal circuitry. Connect to input power via low pass filter
with decoupling to AGND.
Enable for the step-down converter. Active high.
Power-OK pin with open drain output. It is pulled low when the OUTA pin is outside the regu-
lation window. Place a pull-up resistor between POK and OUTA.
Feedback input pin for LDOA. This pin is used to regulate the output of LDOA to the desired
value via an external resistor divider.
LDOA output pin; should be closely decoupled with a low-ESR ceramic capacitor.
Input voltage pin for linear regulator A; should be closely decoupled.
Input voltage pin for linear regulator B; should be closely decoupled.
LDOB output pin; should be closely decoupled with a low-ESR ceramic capacitor.
Exposed paddle; connect to ground directly beneath the package.
2 2504.2007.06.1.0





 AAT2504
Pin Configuration
AAT2504
Adjustable 3-Channel Regulator
QFN34-20
(Top View)
FBB 1
ENA 2
ENB 3
MODE/SYNC 4
FB 5
AGND 6
16 FBA
15 POK
14 EN
13 VIN
12 N/C
11 N/C
Absolute Maximum Ratings1
Symbol
VP, VIN, VLDO
VLX
VFB
VEN
TJ
TLEAD
Description
Input Voltage and Bias Power to GND
LX to GND
FB to GND
EN and EN_LDO to GND
Operating Junction Temperature Range
Maximum Soldering Temperature (at leads, 10 sec)
Thermal Information
Symbol
PD
θJA
Description
Maximum Power Dissipation (TA = 25°C)
Thermal Resistance2
Value
6.0
-0.3 to VP + 0.3
-0.3 to VP + 0.3
-0.3 to 6.0
-40 to 150
300
Units
V
V
V
V
°C
°C
Value
2.0
50
Units
W
°C/W
1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at condi-
tions other than the operating conditions specified is not implied. Only one Absolute Maximum Rating should be applied at any one time.
2. Mounted on an FR4 board.
2504.2007.06.1.0
3



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