si-list RE: 3.3V/5V planes

Bremer, Robert (bremer@littongcs.com)
Thu, 17 Jul 1997 12:18:47 -0700

I agree with the recommended stackup; however, It is preferred to use an
even number of layers and possible reduced cost. You could add an extra
ground layer adjacent to the top to run the components cooler and to
reduce radiated EMI.

Bob Bremer, Mgr. Signal Integrity
Litton Systems.

>-----Original Message-----
>From: fabrizio zanella
>[SMTP:fabrizio=zanella%Eng%EMCHOP1@fishbowl02.lss.emc.com]
>Sent: Thursday, July 17, 1997 7:55 AM
>To: si-list@silab.Eng.Sun.COM
>Subject: 3.3V/5V planes
>
>Stuart, I would recommend a more symmetrical stackup for your board with
>one extra layer. With this stackup every signal layer references a ground
>layer, and the board is more manufacturable.
>
> 1 -------------- top
> 2 -------------- signal
> 3 -------------- ground
> 4 --------------- +5V
> 5 --------------- signal
> 6 --------------- ground
> 7 --------------- signal
> 8 --------------- +3V
> 9 --------------- bottom
>
>Regards,
>
>Fabrizio Zanella
> Sr. Design Engineer
> Hardware Engineering
> _/ _/ email:
>zanella_fabrizio@emc.com
> _/_/_/_/ _/ _/ _/_/_/ _/ voice: (508) 435-1000 Ext.
>4645
> _/ _/_/ _/_/ _/ _/ Fax: (508) 435-8949
> _/_/_/_/ _/ _/ _/ _/ _/_/_/
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> _/_/_/_/ _/ _/ _/_/_/ 171 South Street
> Hopkinton, MA 01748-9103
>