Re: [SI-LIST] : HSTL voltage levels

Gerald Johnson (
Wed, 4 Aug 1999 12:32:36 -0500


What you say is certainly true if one only worries about DC
noise margin. However, if the offending noise were to be so
impolite as to happen during a series of high speed transitions
such as real data, then it would indeed subtract from the=20
AC levels wouldn't it? Therefore the AC noise margin could be
smaller than the DC noise margin. Seems like both are important.
Different, but both important.

Jerry Johnson

> Watch out -- noise margin to the AC numbers is irrelevant. The AC=20
> are guaranteed to cause a change of state, but for noise margin you =
> about the DC thresholds; they are the limits of what is guaranteed to =
> cause a change of state.
> --=20
> D. C. Sessions

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