Re: gEDA-user: basic anti-EMI design q

["Phil Taylor" <phil@xxxxxxxxxxxxxxxxxxxxxxxx>]

Steve Meier <smeier@xxxxxxxxxxxxxxxxxxx> wrote:

> the inducts off or short them. I can not stress enough that when
> debugging complex boards the ability to pop an inductor off and turn off
> the power or isolate one section from another can be very handy.

Steve, I completely agree.  But I just feel like your original explanation
wasn't enough for me.  I get what you're saying.  And I should have been more
clear -- and it's that when you do have transients on your analog board area,
if they arise from EMI ... they will bump up the ground on that analog
section.  With lots of capacitance to the or grounds this wouldn't happen. 
Without some place for that instantaneous charge to go, it'll hit your
inductor on it's way back to the digital side, from whence it came, and your
precious analog ground reference is now being modulated by your interference
noise.

luckily you send it back to digital ground via caps, or board planes.

eh?  phil