[SI-LIST] Re: Convergence problems with Hspice

Khalid,

After we had solved a particularly daunting problem,
one of my old bosses once told me:

"Sometimes, even a blind squirrel runs into an acorn."



Convergence problems are often like that.


best regards,

scott


--
Scott McMorrow
Principal Engineer
SiQual, Signal Quality Engineering
18735 SW Boones Ferry Road
Tualatin, OR  97062-3090
(503) 885-1231
http://www.siqual.com


Khalid Ansari wrote:

> >
> >One more possibility:
> >
> >Sometimes convergence problems will occur when
> >Ansoft package models do not have the correct connections
> >made to power and ground.
>
> Scott,
>
> Well that was the problem, some pins in the package models
> weren't tied to ground through 50 ohms.  Not only did that
> take away my convergence problems but improved some of
> the ringing I was seeing on the output.
>
> Thank you all for your great responses,  it's amazing how much
> information I have gotten on convergence in the past two days.
>
> Khalid
>
> >Be sure that power and ground pass through the model
> >and have different names on the die side of the model.
> >Many people mistakenly (or inadvertently) tie both the
> >die side and the pin side of the model to ground.  This can
> >cause all sorts of convergence problems due to the shorted
> >loop.
> >
> >
> >regards,
> >
> >scott
> >
> >
> >--
> >Scott McMorrow
> >Principal Engineer
> >SiQual, Signal Quality Engineering
> >18735 SW Boones Ferry Road
> >Tualatin, OR  97062-3090
> >(503) 885-1231
> >http://www.siqual.com
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