Powering LED with negative voltage.

[armdnrdy]

Hi,

I was wondering if somebody could clarify this for me. I've noticed that more often than not an LED is powered by the negative voltage in a dual rail system. (+V, 0V, -V )

My question is: what is the advantage? Is it to balance the load?

Thanks,

Larry

[R.G.]

Each situation varies. Every designer (    ) picks the arrangement for their own reasons, and they're often different depending on the knowledge, skill, and lunch menu (Ugh! Bean burritos again!) they have. Balancing load might be a reason. It's just as likely to be for other reasons too.

On a more existential note, LEDs don't care where the voltage/current comes from. All they know is that their head/anode is higher than their feet/cathode.