BCT3220

November, 2008, REV2.0 BCT3220 4 Channel LED Driver (Common-Anode & Common-Cathode) Low Dropout Current Source & Current Sink General Description The BCT3220 is a high performance white LED driver. The BCT3220 uses an internal resistor to set the bias current for four LEDs, which are matched to +/-1.5%. The BCT3220's advantages over ballast resistors include much lower bias variation with supply voltage variation, significantly lower dropout voltage, and in some applications, significantly improved efficiency. The BCT3220 requires only a 50mV dropout voltage at a 20mA load on each output to match the LED brightness. By using one SEL pin, the BCT3220 can support to drive 4 parallel Co-Anode or Co-Cathode white LEDs and regulates a constant current for uniform intensity. Users can easily configure the LED current from 2.5mA to 20mA by a serial pulse. The dimming of white LEDs current can be achieved by applying a pulse signal to the EN pin. There are totally 8 steps of current could be ...