Tri-Colour LED

This is the second type of LED sometimes called a bi-colour LED. It has two independent LEDs in the one package, but with one common leg tied together, make these a three legged LED.  None, one or both LEDs can be illuminated, giving 4 states.  The schematic of the LED is shown below.

As shown in the schematic, these LEDs come in two configurations; common cathode, where the cathodes of the LEDs are connected, and common anode, where the anodes are connected together.

These LEDs require two current limiting resistors and two microcontroller pins.  A tri-colour LED can be connected to any I/O port.  An example a connection is shown below.



Components can be given an optional name.  This is seen in the Test tab. Not all applications support the name.  Hidcomp/hidconfig supports names.


The UsagePage and Usage of the LED. See Usages for more information.


Whether the anodes or the cathodes of the internal diodes are connected together.


Defines the amount of electrical current used by the LED in mA. This is used to estimate the USB power draw.  See the section on Power for more information.

See Also

LED, Bi-colour LED, RGB LED, LEDs