The Chinese semi-conductor manufacturer Worldsemi has developed an RGB-LED that includes a driver chip with a serial interface that allows controlling strings of 1024 of these LEDs using only three wires. The color of each LED can be adjusted individually with a resolution of 24 bits.
The new LED WS2812 includes a WS2811 driver chip in a six-pin SMD5050 package. Three of the pins allow for the connection of the 5 V power supply for the LED and its driver, two other pins are used for the serial data in- and outputs. The remaining sixth pin is not used. The control signals are generated inside the chip which allows increasing the number of LEDs that can be connected in series. By decoupling the driver IC’s power supply at every LED with a low-pass filter (150 ohm / 100 nF) the complete string can be controlled using just three wires.