Re: comparing IBIS model simulation and measurements

Hello, Betty:

It seems that your 1GHz setup should be able to easily measure your
expected slewrate. However, your measured slewrate (6ns for 20%-80%) is
roughly equivalent to a 20MHz sinewave. Is it possible that the 20MHz
filter on your TDS680B scope was inadvertantly enabled?

AC

Betty Luk wrote:
>
> Hi,
>
> 1) simulated slewrate: 2ns (20-80%)
> 2) measured slewrate: 6ns
> 3) scope: Tektronix TDS680B, probe: Tektronix P6245
>
> Thanks,
> Betty
>
> > -----Original Message-----
> > From: Daniel Nilsson [mailto:Daniel.Nilsson@compaq.com]
> > Sent: Monday, November 27, 2000 4:57 PM
> > To: Betty Luk
> > Cc: 'ibis-users@eda.org'
> > Subject: Re: comparing IBIS model simulation and measurements
> >
> >
> > Hi,
> >
> > In order to help you with this I need more information:
> >
> > What is the slewrate you are simulating ?
> > What is the slewrate you are measuring ?
> > What measurement equipment are you using, scope model and
> > probe model ?
> >
> >
> > Regards
> > Daniel Nilsson
> >
> > Betty Luk wrote:
> > >
> > > Hi,
> > >
> > > I've created an IBIS model, and I'm using it with HyperLynx
> > BoardSim.
> > > These results correlate well with Spice simulations, which
> > leads me to
> > > believe that the IBIS model was created correctly from the Spice
> > > model. On the net that I'm simulating, I'm using some Samsung IBIS
> > > models, and some passive components.
> > >
> > > Now I'm trying to compare the HyperLynx simulation with
> > measurements.
> > > I'm noticing that my simulation has a significantly faster slew rate
> > > than my measurements. I've checked my scope probe, and they should
> > > have negligible effect on my measurements. Is this most likely a
> > > deficiency with my original Spice model?
> > >
> > > I would appreciate any feedback!
> > >
> > > Thanks,
> > > Betty Luk
> > >
> >
 
Received on Mon Nov 27 16:25:21 2000