LTC3209-1/LTC3209-2
600mA Main/Camera
LED Controller
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FEATURES
DESCRIPTIO
The LTC®3209-1/LTC3209-2 are highly integrated
multidisplay LED controllers. These parts contain a high
efficiency, low noise charge pump to provide power to
MAIN, CAM and AUX LED displays. The LTC3209-1/
LTC3209-2 require only four small ceramic capacitors
andonecurrentsetresistortoformacompleteLEDpower
supply and current controller.
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Multimode Charge Pump Provides Up to 94%
Efficiency (1x, 1.5x, 2x)
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Up to 600mA Total Output Current
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LTC3209-1: 8 Current Sources Available as
6 × 25mA MAIN, 1 × 400mA CAM and 1 × 15mA AUX
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LTC3209-2: 8 Current Sources Available as
5 × 25mA MAIN, 2 × 200mA CAM and 1 × 15mA AUX
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LED On/Off and Brightness Level Programmable
Themaximumdisplaycurrentsaresetbyasingleexternal
resistor. Current for each LED is controlled by a precision
internal current source. Dimming and On/Off for all dis-
playsisachievedviatheI2Cserialinterface. 256statesare
availablefortheMAINdisplay. Sixteenstatesareavailable
for the CAM display and four states are available for the
AUX display.
Using 2-Wire I2CTM Interface
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Automatic Charge Pump Mode Switching or Fixed
Mode for Power Supply Generation
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Low Noise Constant Frequency Operation*
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Internal Soft-Start Limits Inrush Current During
Start-up and Mode Switching
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Short Circuit/Thermal/Open-Shorted LED Protection
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The charge pump optimizes efficiency based on the
voltage across the LED current sources. The part powers
upin1xmodeandwillautomaticallyswitchtoboostmode
whenever any enabled MAIN or CAM LED current source
begins to enter dropout. The first dropout switches the
part into 1.5x mode and a subsequent dropout switches
the part into 2x mode. The part resets to 1x mode
whenever a data bit is updated via the I2C port. The parts
are available in a 4mm × 4mm 20-lead QFN package.
256 Brightness States for MAIN Display
16 Brightness States for CAM Display
4 Brightness States for AUX Display
20-Lead (4mm ×U4mm) QFN Package
APPLICATIO S
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Video/Camera Phones with QVGA+ Displays
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
*Protected by U.S. Patents, including 6411531
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TYPICAL APPLICATIO
LTC3209-1 6 MAIN/1 CAM Operation
LTC3209-2 5 MAIN/2 CAM Operation
2.2µF
2.2µF
2.2µF
2.2µF
MAIN
CAM
MAIN
CAM
C1P C1M C2P C2M
CPO
C1P C1M C2P C2M
CPO
V
BAT1,2
2.2µF
2.2µF
V
V
BAT
BAT
V
BAT1,2
RED
RED
2.2µF
2.2µF
LTC3209-2
LTC3209-1
SCL
SDA
SCL
SDA
2
2
6
5
2
I C
I C
MAIN1-6
CAM
MAIN1-5
CAM
LOW HI
CAMHL
AUX
GND
LOW HI
CAMHL
AUX
GND
3209 TA01
3209 TA02
R
R
REF
REF
24.3k
24.3k
320912fa
1