I ended up running the serpentine in a wider gap (24 mil to 30 mil)
to allow an accurate clock skew distribution. But, this costed us
more space on the PCB to delay the clocks.
Cisco Systems, Inc
> From owner-si-list@silab.Eng.Sun.COM Wed Sep 24 14:35:44 1997
> The 2nd order effect that Andy alludes to is what I call current jumping
> in a zig-zag pattern. Primarily due to inductive coupling, the active
> signal induces a return current on itself which due to the zig-zag pattern
> propagates in the same direction as the active. The outcome of this effect
> is a net delay decrease.
> So when you force wire in a zig-zag pattern to obtain a certain net delay
> (i.e. for clock balancing, etc.) and expect a To*L result, be careful.
> You may have just added an unwanted skew in your clock distribution or
> pop up early mode surprise in your design.
> > ...
> > What about second-order effects; for example, does the little zig-zag
> > approach allow a weaker wave mode to zip right along as if the
> > zig-zags weren't there?