I know this kind of defeats the purpose of an (common cathode) RGB LED, but if you only wanted Red on a RGB LED would it be acceptable to use only the R pin and the Cathode pin to get just red?
Sorry in advance for my bad grammar.
Electronic – Could You Use Common cathode RGB LED without providing power to G and B
groundingledpowerrgb
Related Solutions
As long as you've got some transistors to drive the LEDs, then you can source your 16-bit PWM from a PSoC3. A single PSoC microcontroller should be able to give you 8x3 16-bit PWM channels. You'll then have to multiplex them.
The PSoC should even be able to handle the multiplexing in hardware, using DMA to stream the image data from memory, and deliver it to the PWM channels. This leaves the CPU to do other important tasks like generating the display data
The PSoC5 has an ARM Cortex M3 core. The good thing about the PSoC chips, though, is that they have re-configurable digital peripherals. This means you can choose to have loads of PWM, or loads of SPI, UARTS, or any combinations. You can wire up all of these peripherals internally, with gates, timers, flip flops, etc.
This means that you can probably make the hardware in the PSoC manage the screen without any intervention by the CPU, giving a good solid image.
This is only a problem if you think in terms of SOURCING a current from an output. Outputs also SINK current.
When the output is set LOW current will flow INTO the pin to ground (SINKING).
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Best Answer
Of course.
Your RGB LED package electrically looks like this:
It contains three LEDs that have their cathodes wired together, so presents a total of 4 pins. Not running current thru any LED isn't going to affect the others.
Note that the point of a RGB LED package is usually to allow arbitrary colors to be displayed. If you had to run all the LEDs at the same current, you wouldn't really have any overall color choice.