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

chenlanbing (rachel.chen@huawei.com.cn)
Wed, 16 Jun 1999 08:59:10 +0800

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HI,

Your question is very good.If you want to know some informations about
the connector in HSSD,you can ask NESA and AMP.These companies have many
practices.Just like your pin map etc.

John Lin (=AAL=B4=C2=B7=D7) wrote:

>
>
> 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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X-MIME-Autoconverted: from 8bit to quoted-printable by engmail1.Eng.Sun.COM id RAA09477

HI,

Your question is very good.If you want to know some informations about the connector in HSSD,you can ask NESA and AMP.These companies have many practices.Just like your pin map etc.

John Lin (=AAL=B4=C2=B7=D7) wrote:

 

Hi all SI experts,

Thank all of you for  giving me good suggestions&= nbsp; 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 h= igh 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 co= nnector because of cost
>issue, what criteria are needed to prove they are el= ectrically equivalent.
>
>Especially the substitution is happened for high spe= ed / 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 cert= ainly have an
effect on the parasitic L & C of the connection.<= /FONT>

One way to check equivalence is to check the sizeof im= pedance
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 conn= ection is placed
in the middle (joining section) of a split idealm 28 ohm line.

Minimum disturbance at 200ps rise time will identify t= he best
electrical connection.  Take care though as elec= trical 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 impe= dance 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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