PRODUCT DATASHEET
AAT3177
ChargePump
TM
General Description
The AAT3177 is a high output current, high efficiency,
low noise, low profile charge pump DC/DC converter.
The device is ideal for multi-functional LED photo-flash
applications where solution cost, size, and efficiency are
critical.
The AAT3177 is capable of driving a regulated output
current up to 800mA. Output current levels can be eas-
ily programmed in 16 steps through AnalogicTech’s
Simple Serial Control™ (S
2
Cwire™) interface controlled
by a single microcontroller GPIO line. This allows smooth
transitions and flexible adjustment of brightness in flash
or other lighting modes. The maximum output current
can also be set with an external R
SET
resistor.
The tri-mode (1X/1.5X/2X) operation of the internal
charge pump offers excellent power efficiency through-
out the output current range for both flash and movie
modes. Combined with a low external parts count (two
1μF flying capacitors and two small bypass capacitors at
V
IN
and OUT), the AAT3177 is ideally suited for small
battery-powered applications.
The AAT3177 has a thermal management system to pro-
tect the device in the event of a short-circuit condition at
the output pin. Built-in soft-start circuitry prevents
excessive inrush current during start-up. The shutdown
feature disconnects the load from V
IN
and reduces quies-
cent current to less than 1μA.
The AAT3177 is available in a Pb-free, thermally-
enhanced 12-pin 3x3mm TDFN package and is specified
over the -40°C to +85°C temperature range.
High Current, High Efficiency Charge Pump with Auto-Timer
Features
•
•
•
•
•
•
•
•
•
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Up to 800mA Output Current
Tri-Mode 1X/1.5X/2X in Current Mode
16 Current Level Steps Set by S
2
Cwire
Flash Auto-Timer (Active for High Current Levels
Only)
External R
SET
to Set Maximum Current
<1μA of Shutdown
Small Application Circuit
No Inductors
Automatic Soft Start
12-Pin TDFN 3x3mm Package
-40°C to +85°C Temperature Range
Applications
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•
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Camcorders
Camera Phones
Digital Still Cameras
PDAs and Notebook PCs
Smart Phones
Typical Application
1μF
1μF
C1+
2.7V
to 5.5V
C
IN
4.7μF
C1-
C2+
C2+
OUT
VIN
AAT3177
EN/SET
CT
GND
C
OUT
2.2μF
Flash
LED
EN
FL
RSET
187K
0.1μF
3177.2008.06.1.0
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