Subject: [IBIS-Users] time shifted edges
From: erik.van.der.ven@philips.com
Date: Mon Aug 18 2003 - 00:55:41 PDT
Dear IBIS colleagues,
I am trying to model a differential LVDS output buffer.
I have generated waveform tables from Spectre simulations. The falling and
rising waveforms look fine at first glance.
In Spectre the falling and rising waveforms (of both outputs, which are
equal) have a crossing point about in the middle of the DC level (high and
low state).
When I simulate my model with Hyperlynx I see that the crossing point is
at a very low level, because of a time shift of the edges. I simulate with
an Rfix (50 Ohm) to a Vfix which is
in the middle of the DC levels.
So my question is:
How does a simulator determine where the edges start? Do different
simulators use the same algorithm for this?
What can I do to get crossing point in the right place? (or: how do I
control the place (in time) of the edges?).
Can anyone help me? Thanks in advance.
With kind regards,
Ir. Erik van der Ven
Room DB1032
Business Line Networking Infrastructure
Philips Semiconductors BV
Gerstweg 2
6534 AE Nijmegen
The Netherlands
Phone: +31-24-3534334
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