LTC3209-1 Datasheet, PDF (1/20 Pages) Linear Technology – 600mA Main/Camera LED Controller

FEATURES
■ _{Multimode Charge Pump Provides Up to 94%}
Efficiency (1x, 1.5x, 2x)
■ _{Up to 600mA Total Output Current}
■ _{LTC3209-1: 8 Current Sources Available as}
6 × 25mA MAIN, 1 × 400mA CAM and 1 × 15mA AUX
■ _{LTC3209-2: 8 Current Sources Available as}
5 × 25mA MAIN, 2 × 200mA CAM and 1 × 15mA AUX
■ _{LED On/Off and Brightness Level Programmable}
Using 2-Wire I²C^TM Interface
■ _{Automatic Charge Pump Mode Switching or Fixed}
Mode for Power Supply Generation
■ _{Low Noise Constant Frequency Operation*}
■ _{Internal Soft-Start Limits Inrush Current During}
Start-up and Mode Switching
■ _{Short Circuit/Thermal/Open-Shorted LED Protection}
■ _{256 Brightness States for MAIN Display}
■ _{16 Brightness States for CAM Display}
■ _{4 Brightness States for AUX Display}
■ _{20-Lead (4mm × 4mm) QFN Package}
U
APPLICATIO S
■ _{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
LTC3209-1/LTC3209-2
600mA Main/Camera
LED Controller
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
and one current set resistor to form a complete LED power
supply and current controller.
The maximum display currents are set by a single external
resistor. Current for each LED is controlled by a precision
internal current source. Dimming and On/Off for all dis-
plays is achieved via the I²C serial interface. 256 states are
available for the MAIN display. Sixteen states are available
for the CAM display and four states are available for the
AUX display.
The charge pump optimizes efficiency based on the
voltage across the LED current sources. The part powers
up in 1x mode and will automatically switch to boost mode
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.
TYPICAL APPLICATIO
LTC3209-1 6 MAIN/1 CAM Operation
LTC3209-2 5 MAIN/2 CAM Operation
2.2µF 2.2µF
2.2µF 2.2µF
V_BAT
2.2µF
C1P C1M C2P C2M _2.2µF
V_BAT1,2
CPO
I²C
LOW HI
LTC3209-1
SCL
SDA
CAMHL
R_REF
6
MAIN1-6
CAM
AUX
GND
24.3k
MAIN
CAM
RED
3209 TA01
V_BAT
2.2µF
C1P C1M C2P C2M _2.2µF
V_BAT1,2
CPO
LTC3209-2
SCL
I²C
SDA
LOW HI
CAMHL
R_REF
24.3k
5
MAIN1-5
2
CAM
AUX
GND
MAIN
CAM
RED
3209 TA02
320912fa
1