Re: Question about differential devices

BENOIT.B.M.MEYNIEL@RCM.thomson.fr wrote:
>
> Hey,
>
> I would like to know if the value of the differantial input impedance of the
> differential receivers is taking into account into the IBIS specifications.
> This value is typically very high but its influence can be important concerning
> the quiecent points of the numerical links.
> Anyone who is familiar with this please give me some coments .

There is at present no explicit differential-impedance characterization.
OTOH:

1) I'm not aware of many devices which actually have a path directly
   between the two inputs. What paths there are are typically
   reactive anyway.

2) The clamp curves are actually more general than a single scalar
   impedance for the inputs in isolation.

3) The v3 extensions make it possible to add explicit paths between
   pins, even to the extent of multiport networks. Not fun, but
   then again shouldn't be needed very often.

-- 
D. C. Sessions
dc.sessions@tempe.vlsi.com