Good morning everyone,

Plese bear with me on this one. Basically an
engineer and I are having a p!##ing contest
concerning moats.

On the design he wants a "moat" placed on the
ground plane around certain power pins.

Now this moat is NOT an isolated plane. Basically
it is a long "U" shaped slot in the ground plane.
His reasoning is that it keeps noise from coupling
onto the pins.

Does anyone practice this? I understand isolating planes,
especially analog/digital circuitry. However this slot
in the ground plane does not make sense to me. The
pins aren't not truly isolated from the plane.

Now I've looked in the "High-Speed Digital Design" book
and didn't find info on this subject. Plenty on crosstalk
over slots, how to moat (true moats) and things of that
nature. I've looked on the email archives and checked out
a few web sites. Still no definite answer. Someone please
enlighten me.

Thanks
Dennis