LTC3219 Datasheet, PDF (1/20 Pages) Linear Technology – 250mA Universal Nine Channel LED Driver

LTC3219
250mA Universal
Nine Channel LED Driver
FEATURES
■ _{Multimode Charge Pump Provides Up to 91%}
Efficiency
■ _{Slew Limited Switching Reduces Conducted and}
Radiated Noise (EMI)
■ _{Up to 250mA Total Output Current}
■ _{Nine 28mA Universal Current Sources with 64-Step}
Linear Brightness Control
■ _{Independent On/Off, Brightness Level, Blinking and}
Gradation Control for Each Current Source Using
2-Wire I²C^TM Interface
■ _{Internal Current Reference}
■ _{Configurable ENU Pin for Asynchronous LED On/Off}
Control
■ _{Low Noise Charge Pump Operates in 1x, 1.5x or 2x}
Mode for Optimal Efficiency*
■ _{Automatic or Forced Mode Switching}
■ _{Internal Soft-Start Limits Inrush Current}
■ _{Short-Circuit/Thermal Protection}
■ _{3mm × 3mm 20-Lead QFN Plastic Package}
APPLICATIONS
■ _{Video Phones with QVGA+ Displays}
DESCRIPTION
The LTC^®3219 is a highly integrated multidisplay LED
driver. The device contains a high efficiency, low noise
charge pump to provide power to nine universal LED
current sources. The LTC3219 requires only five small
ceramic capacitors to form a complete LED power supply
and current controller.
The maximum display currents are set by an internal pre-
cision current reference. Independent dimming, On/Off,
blinking and gradation control for all current sources is
achieved via the I²C serial interface. 6-bit linear DACs are
available for adjusting brightness levels for each universal
LED current source.
The LTC3219 charge pump optimizes efficiency based on
the voltage across the LED current sources. The device
powers up in 1x mode and will automatically switch 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 LTC3219 into 2x mode. The part resets to 1x mode
whenever a data register is updated via the I²C 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.
TYPICAL APPLICATION
C2
1μF
4-LED Main, 2-LED Sub and RGB
C3
1μF
C1P C1M C2P C2M
MAIN
SUB
V_BAT
C1
V_BAT
CPO
C4
2.2μF
LTC3219
2.2μF
I²C
2 _SCL/SDA
ULED1-9 ⁹
DV_CC
DV_CC
0.1μF
ENABLE DISABLE
ENU GND
RGB
3219 TA01a
3219fa
1