PWM multiple 7-segment LEDs

[Demon]

Wouldn't it be simpler with common cathode? That way you only have a single sink transistor/fet for each set of digits, making it easy to PWM.

Hmm, is sink more efficient than source?


EDIT: Gotten from a quick google:

'While this may sound strange or non-ideal, it is generally easier for the microcontroller to shunt this current to ground and absorb a little power as heat rather than try and generate the sourcing current. Sourcing current can cause large voltage swings on the input which can introduce noise.'

Interesting, I never really put a lot of thought in this before.

I suppose that's because the PIC didn't have to source the power consumed by the device, only the leftovers.

Where-as if it has to source, it has to source everything. Never thought of that.