AAT1142 Datasheet, PDF (1/22 Pages) Advanced Analogic Technologies – 800mA Voltage-Scaling Step-Down Converter

AAT1142
800mA Voltage-Scaling Step-Down Converter
General Description
Features
SwitchReg^™
The AAT1142 SwitchReg is a dynamically pro-
grammable 2.2MHz step-down converter with an
input voltage range of 2.7V to 5.5V and output from
0.6V to 2.0V. Its low supply current, high level of
integration, and small footprint make the AAT1142
the ideal choice for microprocessor core power in
systems such as smartphones.
The 2.2MHz switching frequency allows the use of
a small external inductor and capacitors. Peak cur-
rent mode control and internal compensation pro-
vide stable operation and fast voltage response
without over/undershoot or ringing.
The AAT1142 delivers up to 800mA of output current
while consuming 35µA of typical no load quiescent
current. Dynamic Voltage Management is provided
through I²C or AnalogicTech's S²Cwire™ (Simple
Serial Control™) single wire interface. The user can
program the output from 0.6V to 2.0V in 50mV steps.
The AAT1142 optimizes power efficiency through-
out the load range via PWM/PFM mode. Pulling
the MODE/SYNC pin high enables PWM Only
mode, maintaining constant frequency and low
noise across the operating range. Alternatively, the
converter may be synchronized to an external
clock input via the MODE/SYNC pin. Over-temper-
ature and short-circuit protection safeguard the
AAT1142 and system components from damage.
The AAT1142 is available in a Pb-free, space-sav-
ing 2.85x3.0x1.0mm TSOPJW-12 package or a
Pb-free, low-profile 3x3x0.8mm TDFN33-12 pack-
age. The device is rated over the -40°C to +85°C
temperature range.
Typical Application
VIN: 2.7V to 5.5V
C2
4.7µF
VIN
LX
AAT1142
FB
I ²C
S²Cwire*
*Optional S²Cwire or I²C Input
MODE/SYNC
SDA
SCL
EN/SET
AGND
PGND
VOUT: 0.6V to 2.0V
800mA Maximum
L1
2.2µH
C1
10µF
• V_IN Range: 2.7V to 5.5V
• V_OUT Programmable Range: 0.6V to 2.0V
• Dynamic Voltage Management:
— 50mV Output Resolution
— Fast, Stable Response
• Serial Control Options:
— I²C Two-Wire Interface
— S²Cwire Single-Wire Interface
• 800mA Output Current
• Up to 93% Efficiency
• Line, Load Regulation Less Than ±0.5%
• 2.2MHz Switching Frequency
• Ultra-Small External Filter
• Low 35µA No Load Quiescent Current
• 100% Duty Cycle Low Dropout Operation
• Internal Soft Start
• Over-Temperature Protection
• Current Limit Protection
• Multi-Function MODE/SYNC Pin:
— PFM/PWM for High Efficiency
— PWM Only for Low Noise
— Clock Input to Synchronize to System Clock
• TSOPJW-12 or TDFN33-12 Package
• Temperature Range: -40°C to +85°C
Applications
• Camcorders
• Cellular Phones and Smartphones
• Digital Still Cameras
• Handheld Instruments
• Microprocessor / DSP Core
• MP3, Portable Music, and Portable Media
Players
• PDAs and Handheld Computers
Efficiency vs. Load
(V_OUT = 1.8V)
100
90 ^{VIN = 3.6V VIN = 2.7V}
80
70
V_IN = 4.2V
60
V_IN = 5.0V
50
40
PWM Only
Mode
30
0
1
10
100
1000
Output Current (mA)
1142.2006.07.1.0
1