18-Channel LED Driver
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
www.DataShneetL4Uo.wcoNmoise 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 I2C Addresses Are Available (LTC3220: 0011100,
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
n Video Phones with QVGA+ Displays
n Keypad Lighting
n General/Miscellaneous Lighting
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.
6-LED Main, 4 RGB LEDs
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