Re: [IBIS] How to model analog I/Os

Hi Cathy:

Standard IBIS covers just digital I/Os, terminators and series
elements.

I would use NC or some terminator model to stub off the analog
pins because most EDA tools would not expect models on them or
process them correctly.

For some special cases you could use an IBIS buffer to mimic
an expected analog output signal and impedance - such as for
the output of an analog amplifier.  Then a test analog waveform
could generated for that pin for simulating the analog
signal characteristics along its path.

But I still recommend just stubbing off the analog pins for
standard commercial parts to avoid confusion and unexpected
signals.

Bob


Cathy Xu wrote:
 > Hi,
 > I'm not sure if IBIS supports analog I/O's. Should we model them the
 > same way
 > as digital I/O buffers or just put N/A's? We got some analog circuits
 > with 12V supply
 > and feedbacks on the outputs.
 >
 > Thanks,
 > Cathy
 >
 >


-- 
Bob Ross
Teraspeed Consulting Group LLC     Teraspeed Labs
121 North River Drive              13610 SW Harness Lane
Narragansett, RI 02882             Beaverton, OR 97008
401-284-1827                       503-430-1065
http://www.teraspeed.com           503-246-8048 Direct
bob@teraspeed.com

Teraspeed is a registered service mark of Teraspeed Consulting Group LLC



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