PRODUCT DATASHEET
AAT3172
ChargePump
TM
General Description
The AAT3172 is a high output current, high efficiency,
low noise, low profile charge pump DC/DC converter,
ideal for multi-function LED photo-flash applications
where solution cost, size, and efficiency are critical.
The dual charge pump in the AAT3172 is capable of deliv-
ering 600mA output current. Two current-controlled paths
are available for users of dual flash LEDs that prefer cur-
rent matching. Each LED channel can be easily pro-
grammed in 32 steps with a single GPIO output through
the AS
2
Cwire™ (Advanced Simple Serial Control™) inter-
face. This allows smooth transitions and flexible adjust-
ment of brightness in flash or other lighting modes.
The tri-mode (1X/1.5X/2X) operation of the internal
charge pump offers excellent power efficiency for both
flash and movie modes. Combined with a low external
parts count (two 1µF flying capacitors and one small
bypass capacitor at V
IN
and OUT), the AAT3172 is ideally
suited for small, battery-powered applications.
The AAT3172 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 1.0µA.
The AAT3172 is available in the Pb-free, thermally-
enhanced, 12-pin 3x3mm TDFN package.
High Current LED Flash Driver Charge Pump IC
Features
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V
IN
Range: 2.7V to 5.5V
600mA Output Current
Tri-Mode 1X/1.5X/2X in Current Mode
Voltage Mode Operation: 1.5X, 100mA
Dual Regulated Current Sinks
Current Match Between Current Sinks
32 Current Steps Set by AS
2
Cwire
1µF Input, Output, and Flying Capacitors
<1.0µA 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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Camera Phones
Digital Still Cameras (DSCs)
PDAs and Notebook PCs
Smart Phones
Typical Application
C1
1µF
C2
1µF
C1+
2.7V to 5.5V
C
IN
4.7µF
C1- C2+
C2-
V
OUT
V
IN
AAT3172
C
OUT
2.2µF
Flash
LED 1
Flash
LED 2
F1
EN/SET
EN/SET
GND
F2
3172.2008.04.1.6
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