High Efficiency 1X/1.5X/2X Charge Pump
for RGB Color LED Applications
General Description
The AAT3129 is a high efficiency charge pump
DC/DC converter with tri-mode load switch (1X)
fractional (1.5X) and doubling (2X) conversion for
color LED applications. A single current source out-
put provides a regulated current to drive R, G, and
B LEDs via three internal switches. With a simple
single wire serial bus, the RGB module can be eas-
ily controlled to display 4096 colors.
AnalogicTech's Advanced Simple Serial Control™
(AS
2
Cwire™) serial digital input is used to enable,
disable, and set the duty cycle of each internal
MOSFET switch. Low external parts count (two
1μF flying capacitors and two small bypass capac-
itors at V
IN
and OUT) makes the AAT3129 ideally
suited for small battery-powered applications.
The AAT3129 has a thermal management system
to protect the device in the event of a short-circuit
condition on any of the output pins. Built-in soft-
start circuitry prevents excessive inrush current
during start-up. High switching frequency enables
the use of small external capacitors. A low current
shutdown feature disconnects the load from V
IN
and reduces quiescent current to less than 1μA.
The AAT3129 is available in a Pb-free, 12-pin
TSOPJW package.
AAT3129
Features
•
•
•
•
•
•
•
•
•
•
•
•
ChargePump
™
V
IN
Range: 2.7V to 5.5V
Common Anode RGB LED Control
4096 Color with Single Wire Digital Control
40mA to 180mA Fixed Current Source
AS
2
Cwire Digital Brightness Control
Low Noise Constant Frequency Operation
Small Application Circuit
Regulated Output Current
No Inductors
1MHz Switching Frequency
I
Q
<1μA in Shutdown
12-Pin TSOPJW Package
Applications
•
•
•
•
•
•
•
•
Fashion RGBs
Mobile Handsets
MP3 Players
PDAs
Portable Devices
RGB Color LEDs
RGB Photo Flash
Smart Phones
Typical Application
VIN
ISRC
C1+
V
BAT
C
IN
1μF
C
CP
1μF
CP
AAT3129
C1-
C2+
C1
1μF
R
C2
1μF
G
B
C2-
EN/SET
EN/SET
GND
DR
DG
DB
3129.2007.01.1.4
1
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
