RE: [SI-LIST] : connector substitution for high speed signals

=?Big5?B?Sm9obiBMaW4gKKpMtMK31yk=?= (John@quantatw.com)
Fri, 11 Jun 1999 08:34:57 +0800

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Hi all SI experts,

Thank all of you for giving me good suggestions regarding to=20
equivalent connectors in high speed environment.

What I think is that if I can have same pattern of pin assignment, same
signal return and signal -ground ratio
as well as compensation of impedance disruption, then I shall be able =
to do
connector substistuion.

Any comment?
=20
Thanks,
John Lin
CAE Engineer
Quanta Computer Inc.

-----Original Message-----
From: Andy Burkhardt [mailto:andyb@polar.co.uk]
Sent: Thursday, June 10, 1999 10:08 PM
To: John Lin (=AAL=B4=C2=B7=D7)
Cc: Casey; Amit Bhardwaj; Richard S Smith
Subject: Re: [SI-LIST] : connector substitution for high speed signals

At 09:01 07/06/99 +0100, you wrote:
>Hi All SI Experts,=20
>
>One question.=20
>
>If I want to use one connector to replace another connector because of =
cost
>issue, what criteria are needed to prove they are electrically =
equivalent.=20
>
>Especially the substitution is happened for high speed / low swing =
signals,
>such as RAMBUS signals, which have 200ps for rising time.
>
>Any comments or suggestions are appreciated.=20
>
>Thank you for helps in advance.=20
>
>John Lin=20
>Quanta Computer Inc.=20
>CAE Engineer=20
>Tel: 1+886+03+3979000 ext. 5183=20
>Fax: 1+886+03+3975000=20
>Email: John@quantatw.com=20

Dear John,

Check physical dimensions carefully as these will certainly have an
effect on the parasitic L & C of the connection.

One way to check equivalence is to check the sizeof impedance
discontinuity caused by each connector type.

(For Rambs) You can TDR a perfect 28 ohm transmission line and compare
the size of the impedance discontinuity when the connection is placed
in the middle (joining section) of a split idealm 28 ohm line.

Minimum disturbance at 200ps rise time will identify the best
electrical connection. Take care though as electrical and mechanical
compromises are often necessary, so reliability, ease of use, etc...
may also be affected.

Hope this helps.

Best regards

Andy Burkhardt
Product Manager
Email: mail@polar.co.uk
Tel: + 44 1481 253081
Fax: + 44 1481 252476
http://www.polar.co.uk
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D
World leaders in PCB faultfinding and controlled impedance measurement
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D

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RE: [SI-LIST] : connector substitution for high speed = signals

Hi all SI experts,

Thank all of you for  giving me good = suggestions  regarding to
equivalent connectors in high speed = environment.

What I think is that if I can have same pattern of = pin assignment, same signal return  and signal -ground = ratio
 as well as compensation of impedance = disruption, then I shall be able to do connector substistuion.

Any comment?
 
Thanks,
John Lin
CAE Engineer
Quanta Computer Inc.

-----Original Message-----
From: Andy Burkhardt [mailto:andyb@polar.co.uk]
Sent: Thursday, June 10, 1999 10:08 PM
To: John Lin (=AAL=B4=C2=B7=D7)
Cc: Casey; Amit Bhardwaj; Richard S Smith
Subject: Re: [SI-LIST] : connector substitution for = high speed signals


At 09:01 07/06/99 +0100, you wrote:
>Hi All SI Experts,
>
>One question.
>
>If I want to use one connector to replace = another connector because of cost
>issue, what criteria are needed to prove they = are electrically equivalent.
>
>Especially the substitution is happened for high = speed / low swing signals,
>such as RAMBUS signals, which have 200ps for = rising time.
>
>Any comments or suggestions are appreciated. =
>
>Thank you for helps in advance.
>
>John Lin
>Quanta Computer Inc.
>CAE Engineer
>Tel: 1+886+03+3979000 ext. 5183
>Fax: 1+886+03+3975000
>Email: John@quantatw.com

Dear John,

Check physical dimensions carefully as these will = certainly have an
effect on the parasitic L & C of the = connection.

One way to check equivalence is to check the sizeof = impedance
discontinuity caused by each connector type.

(For Rambs) You can TDR a perfect 28 ohm transmission = line and compare
the size of the impedance discontinuity when the = connection is placed
in the middle (joining section) of a split idealm 28 = ohm line.

Minimum disturbance at 200ps rise time will identify = the best
electrical connection.  Take care though as = electrical and mechanical
compromises are often necessary, so reliability, = ease of use, etc...
may also be affected.

Hope this helps.


Best regards

Andy Burkhardt
Product Manager
Email: mail@polar.co.uk
Tel: + 44 1481 253081
Fax: + 44 1481 252476
http://www.polar.co.uk
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D
World leaders in PCB faultfinding and controlled = impedance measurement
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D

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