PRODUCT DATASHEET
AAT2500B
SystemPower
TM
General Description
The AAT2500B 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 step-down converter delivers up to 800mA of output
current, while consuming 30μA of typical no load quies-
cent current. The switching frequency is 2MHz, minimiz-
ing the size of external components.
The two LDOs (LDOA/LDOB) have independent inputs
and are capable of delivering up to 500mA and 150mA
respectively. 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 drop-
out voltage. The output voltages for both LDOs are
adjustable to as low as 0.6V. The linear regulators have
independent Enable pins.
The AAT2500B is available in a Pb-free 3x4mm QFN34-20
package and is rated over the -40°C to +85°C tempera-
ture range.
Adjustable 3-Channel Regulator
Features
• V
IN
Range: 2.7V to 5.5V
• 800mA Buck Converter
• Linear Regulators
▪
LDOA: 500mA
▪
LDOB: 150mA
• Adjustable Output Voltage
• Low Dropout Voltage
• High Output Accuracy: ±1.5%
• High Efficiency Step-Down Converter
• 85μA (Typical) of Total I
Q
• Independent Enable Pins
• Integrated Power MOSFETs
• 2MHz Switching Frequency
• Over-Temperature and Current Limit 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
Typical Application
L
LX
AAT2500B
FB
V
IN
VIN
VLDOA
VLDOB
VP
SYNC
ENA
ENB
EN
PGND
AGND
OUTA
100kΩ
POK
FBA
OUTB
OUTB
POK
V
OUT
(Buck)
R
1
R
1A
OUTA
C
OUT
R
1B
FBB
R
2A
2.2μF
2.2μF
R
2
R
2B
2500B.2008.03.1.0
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