Re: [SI-LIST] : another stack-up question

D. C. Sessions (dc.sessions@tempe.vlsi.com)
Fri, 01 May 1998 07:57:40 -0700

Andrew Phillips wrote:
>
> Hi,
>
> There was a recent discussion on this list regarding a stack-up proposal
> for a 10-layer board. Here's another one:
>
> signal
> GND
> signal
> signal
> PWR
> GND
> signal
> signal
> GND
> signal
>
> I'd be interested in any comments on the merits (or lack of) for this
> arrangment

Return currents will see a different impedance on PWR vs GND, for one.
Worse, the returns on 7 & 8 will have to cross layers to get to PWR,
which should make for (1) much more noise, and (2) assymetrical edges
at the receiver.

-- 
D. C. Sessions
dc.sessions@tempe.vlsi.com