LTC3220 Datasheet | Linear Technology

Features n Eighteen 20m A 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 360m A 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, 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 LTC3220/LTC3220-1 360m A Universal 18-Channel LED Driver Description The LTC®3220/LTC3220-1 are highly integrated multidisplay 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 plete LED power supply and current controller. The LED currents are set by an internal precision current reference. Independent dimming, on/off, blinking and gradation control for all universal current sources are 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,...