Re: [SI-LIST] : "Best" way to ground board?

Georg Ramsch (
Fri, 09 Jul 1999 08:54:19 +0200

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Hello, Chris !

Chris Bobek wrote:
> I am designing a 10 layer VME board that has two edge connectors (P1 and
> P2). The connectors are about 4" long each with grounds distributed along
> the length of each connector.
> What is a good way to ground the two GND planes on our board?
> A) Simply ground each GND pin to both GND planes at the pin.


> B) Something else?

Which type of connector do you use ?

1) Standard VME DIN41612 / 96 pin
2) VME64ext
3) 4 row DIN41612 / 4 row is shield
4) 5 row DIN41612, where two rows are shield.

> The reason I'm thinking of this is because I can imagine a ground loop
> occurring between the outer GND pins of the connectors that are a total of
> about 9" away. My guess is that the simple approach will be fine, but I'm
> curious as to other opinions.

GND loop is within the connector pinning of VME, therefore upper pins of P1 have
highest noise levels.

Distinguish in betweeen GND on backplane and GND on plug-in-board !

What driver technology do you use ? (ABT/FCT/ABTE......?)

CU :-)

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