LTC3207/LTC3207-1
600mA Universal
Multi-Output LED/CAM Driver
FEATURES
DESCRIPTION
TheLTC®3207/LTC3207-1arehighlyintegratedmulti-display
LEDdrivers.Thedevicecontainsahigh-efficiency,low-noise
chargepumptoprovidepowerto12universalLEDcurrent
sourcesandonecameraLEDcurrentsource.TheLTC3207/
LTC3207-1 require only five small ceramic capacitors to
form a complete LED power supply and current controller.
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Low Noise, Multi-Mode Charge Pump (1x, 1.5x, 2x)
Provides Up to 91% Efficiency
■
Slew Limited Switching Reduces Conducted and
Radiated Noise (EMI)
Up to 600mA Total Output Current
■
■
Twelve 28mA Universal Current Sources with
2
64-Step Linear Brightness Control
In addition there are two I C addresses available.
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425mA CAM LED Current Source with 16-Step
The display currents are set by an internal precision cur-
rent reference. Independent dimming, On/Off, blinking
and gradation control for all universal current sources is
Linear Brightness Control and 2-Second High
Current Safety Timer
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Independent On/Off, Brightness Level, Blinking and
2
achieved via the I C serial interface. 6-bit linear DACs are
Gradation Control for Each Current Source Using
available for adjusting brightness levels for each universal
LED current source. The CAM current source has a 4-bit
linear DAC to adjust brightness.
2
2-Wire I CTM Interface
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Internal Current Reference
2
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Two I C Addresses are Available
TheLTC3207/LTC3207-1chargepumpsoptimizeefficiency
based on the voltage across the LED current sources. The
devicepowers-upin1xmodeandwillautomaticallyswitch
to boost mode whenever any enabled LED current source
begins to enter dropout. The first dropout switches the
IC into 1.5x mode and a subsequent dropout switches
the LTC3207/LTC3207-1 into 2x mode. The device resets
to 1x mode whenever a data register is updated via the
(LTC3207 00110110, LTC3207-1 00110100)
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Configurable ENU Pin for Asynchronous LED
On/Off Control
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Automatic or Forced Mode Switching
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Internal Soft-Start Limits Inrush Current
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Short-Circuit/Thermal Protection
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4mm × 4mm 24-Pin QFN Plastic Package
2
APPLICATIONS
I C port.
+
, 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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Video Phones with QVGA Displays
TYPICAL APPLICATION
4-LED MAIN, 2-LED SUB, Dual RGB and Camera Light
C2
2.2µF
C3
2.2µF
MAIN
SUB
RGB
RGB
CAM
C1P C1M C2P C2M
V
BAT
V
BAT
CPO
C1
C4
4.7µF
2.2µF
LTC3207/LTC3207-1
DV
DV
CC
CC
0.1µF
2
12
ULED1-12
CAM
2
I C
SCL/SDA
ENU
3207 TA01
ENABLE DISABLE
LOW HI
CAMHL
GND
3207fc
1