Ralph;

The revision "A" of IPC-D-317 contains formulas for differential stripline
in flatwire as welss as wire conductors. It also gives something on
differential microstrip. It's too difficult type a formula here. If you
cannot find a copy of the spec, send me you fax number and I will send a
copy of the appropriate page.

Regards,

Gary

At 09:43 AM 6/6/96 -0700, Ralph Hersey wrote:
>                      Subject:                              Time:  9:33 AM
>  OFFICE MEMO         DES: True Differential Striplines     Date:  6/6/96
>
>Hi all, we have a problem finding the design requirements (formulas) for true
>differential strip transmission lines, see the following sketch
>
>sgsgsgsgsgsgsgsgsgsgs -- the sg's are signal grounds (planes)
>ddddddddddddddddddddd -- the d's are dielectric
>ddddddddddddddddddddd
>ddddddddsssssssdddddd -- the s's are signal layers (superimposed)
>ddddddddddddddddddddd
>ddddddddsssssssdddddd
>ddddddddddddddddddddd
>ddddddddddddddddddddd
>sgsgsgsgsgsgsgsgsgsgs
>
>We have done a bunch of literature searches to find the formulas to model
>differential transmission lines to no avail.
>
>The differential transmission line impedance we are needing is in the range of
>20-50 ohms.
>
>We think the signal ground planes have minimal impact on the impedance of the
>differential transmission line.
>
>Any help/thought will be appreciated, and thanks a lot, ahead of time.
>
>Ralph Hersey
>Lawrence Livermore National Laboratory
>e-mail:  [log in to unmask]
>
>If possible "cc" (close copy) your response to:
>
>Jim Zumstein
>e-mail:  [log in to unmask]
>
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