PRODUCT DATASHEET
AAT2786
SystemPower
TM
General Description
The AAT2786 is a dual output power solution. It includes
a 1.5A, 1.4MHz, high-efficiency step-down converter and
a high performance 150mA LDO regulator. The step-
down regulator output voltage is adjustable from 0.6V to
V
IN
. The LDO regulator has a factory preset fixed output
voltage from 1.2V to 3.3V.
The step-down converter consumes only 42µA of no-load
quiescent current and is designed to maintain high effi-
ciency throughout the load range. The step-down con-
verter has ultra-low R
DS(ON)
integrated MOSFETs and can
operate up to 100% duty cycle to enable high output
voltage, high current applications which require a low
dropout threshold. The AAT2786 provides excellent tran-
sient response and high output accuracy across the
operating range. Pulling the MODE/SYNC pin high
enables “PWM Only” mode, maintaining constant fre-
quency and low output ripple across the operating range.
Alternatively, the converter may be synchronized to an
external clock input via the MODE/SYNC pin.
The MicroPower low dropout linear regulator in the
AAT2786 has been specifically designed for high-speed
turn-on and turn-off performance, fast transient response,
and good noise and power supply ripple rejection (PSRR),
making it ideal for powering sensitive circuits with fast
switching requirements.
Over-temperature and short-circuit protection safeguard
the AAT2786 and system components from damage.
1.5A Step-Down Converter and 150mA LDO
Features
•
V
IN
Range : 2.5V to 5.5V
•
1.5A Step-Down Converter
▪
V
OUT
Range: 0.6V to V
IN
▪
95% Peak Efficiency
▪
High Efficiency across load range
▪
42µA No Load Quiescent Current
▪
Optional “PWM Only” Low Noise Mode
▪
Current limit and soft start
•
150mA LDO Regulator
▪
V
OUT
Range: 1.2V to 3.3V (Fixed)
▪
High Power Supply Rejection Ratio
▪
Low Output Noise
•
Independent Enable Pins
•
Integrated Power MOSFETs
•
Over-Temperature Protection
•
TDFN34-16 Package
• -40°C to +85°C Temperature Range
Applications
•
•
•
•
•
Cellular and Smart Phones
PDAs, Palmtops
Digital Still and Video Cameras
Portable Instruments
Battery-Powered Applications
Typical Application
U1
BUCK IN
R1
100
C1
opt
C2
10µF
C3
1µF
ON/OFF
ON/OFF
LDO IN
ON/OFF
C6
1µF
C8
10nF
16
15
12
L1
LX
LX
FB
1
VP
VP
VIN
BUCK_EN
MODE/SYNC
LDOIN
LDO_EN
BYP
BUCK OUT
3.3µH
R2
Adj
C5
Opt
2
5
C4
22µF
13
14
AAT2786IRN
GND
4
R3
59k
11
9
8
LDO_OUT
6
LDO OUT
PGND
3
C7
2.2µF
7
10
N/C
LDO_GND
2786.2008.04.1.0
www.analogictech.com
1
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
