Dr. Howard Johnson mentioned a technology which solved your problem named
"drawbridge" in one of his newsletter. You can find this article on his Web
And someone in this list mentioned a "fense" technology deal with your
situation while has higher isolation ratio. I can't recall the detail. If
you get something about this, please give me a copy.
> -----Original Message-----
> From: Lum Wee Mei [SMTP:email@example.com]
> Sent: Wednesday, August 11, 1999 8:09 AM
> To: 'firstname.lastname@example.org'
> Subject: [SI-LIST] : RF & Digital
> If I have a design that have digital circuit and a small portion of RF.
> There will be some signals going from digital into the RF and out from
> the RF to the digital portion. If the digital portion has to be
> impedance control at 50ohms, how should I go about doing such design to
> ensure that both RF and Digital requirements are taken care of, without
> causing any interference between these two circuits? What about the
> ground? This design will be a 10-layer with the following stack-up :
> L1 : signal
> L2 : GND
> L3 : +5V
> L4 : signal
> L5 : signal
> L6 : signal
> L7 : signal
> L8 : +2.5V
> L9 : GND
> L10 : signal
> I would appreciate any advise from you experts out there.
> Thanks and regards.
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