LTC3220_15 Datasheet, PDF (1/20 Pages) Linear Technology – 360mA Universal 18-Channel LED Driver

LTC3220/LTC3220-1
360mA Universal
18-Channel LED Driver
FEATURES
n _{Eighteen 20mA Universal Current Sources with}
64-Step Linear Brightness Control
n _{Independent On/Off, Brightness Level, Blinking and}
Gradation Control for Each Current Source Using
2-Wire I²C Interface
n _{Low Noise Multi-Mode Charge Pump (1x, 1.5x, 2x)}
Provides Up to 91% Efficiency
n _{Slew Limited Switching Reduces Conducted and}
Radiated Noise (EMI)
n _{Up to 360mA Total Output Current}
n _{Internal Current Reference}
n _{Single Reset Pin for Asynchronous Shutdown and}
Reset of All Data Registers
n _{Two I}²_{C Addresses Are Available (LTC3220: 0011100,}
LTC3220-1: 0011101)
n _{Automatic or Forced Mode Switching}
n _{Internal Soft-Start Limits Inrush Current}
n _{Short-Circuit/Thermal Protection}
n _{4mm × 4mm Ultrathin (0.55mm) 28-Lead QFN}
Package
APPLICATIONS
n _{Video Phones with QVGA+ Displays}
n _{Keypad Lighting}
n _{General/Miscellaneous Lighting}
DESCRIPTION
The LTC3220/LTC3220-1 are highly integrated multi-display
LED drivers. These parts contain a high efficiency, low noise
charge pump to provide power to up to eighteen universal
LED current sources. The LTC3220/LTC3220-1 require
only five small ceramic capacitors to form a complete
LED power supply and current controller.
The LED currents are set by an internal precision cur-
rent reference. Independent dimming, on/off, blinking
and gradation control for all universal current sources
is achieved via the I²C serial interface. 6-bit linear DACs
are available to adjust brightness levels independently for
each universal LED current source.
The LTC3220/LTC3220-1 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 LED current source
begins to enter dropout. The first dropout switches the
parts into 1.5x mode and a subsequent dropout switches
the LTC3220/LTC3220-1 into 2x mode. The parts reset to
1x mode whenever a data bit is updated via the I²C port.
L, 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
2.2μF
C3
2.2μF
6-LED Main, 4 RGB LEDs
V_IN
DV_CC
C1
2.2μF
C1P C1M C2P C2M
V_IN
CPO
LTC3220
LTC3220-1
DV_CC
0.1μF
ULED1-18
I²C
RESET
SCL/SDA
RST
GND
C4
4.7μF
18
RGB1
RGB2
RGB3
RGB4
MAIN
3220 TA01
32201fc
1