February, 2009, REV2.
01
BCT3221
4 Channel LED Driver (Common-Anode & Common-Cathode)
Low Dropout Current Source & Current Sink
General Description
The BCT3221 is a high performance white LED driver.
The BCT3221 uses an internal resistor to set the bias current for four LEDs, which are matched to +/-1.
5%.
The BCT3221'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 BCT3221 requires only a 50mV dropout
voltage at a 20mA load on each output to match the LED brightness.
By using one SEL pin, the BCT3221 can support to drive 4 parallel Co-Anode...