Subject: Egg10 Implementation

From: Chris Rokusek <[email-masked]>
Date: Wed, 30 Oct 96 12:23:38 PST

Hi All,

I've got a working version of ibischk2 that compares AC waveform
endpoint voltages against the (DC) VI curves and the correspond test
fixture.

I need to define a tolerance of some sort to which the voltages agree.
This relates to prior discussion of how long a waveform needs to
settle.  The spec does not provide a tolerence...

     Keywords:     [Rising Waveform], [Falling Waveform]
     .
     .
     .
                   A waveform table must include the entire waveform;
                   i.e., the first entry (or entries) in a voltage column
                   must be the DC voltage of the output before switching
                   and the last entry (or entries) of the column must be
                   the final DC value of the output after switching.

I think we need to define a % voltage that the first/last entries must
lie within (e.g. 2.0%).  

Percent of what, though?  Well, how about percent of 0% to 100% of the
waveform endpoint voltages difference itself.  This would require a
highly loaded waveform to settle to a more absolute voltage since it
would have a smaller voltage swing.  Is this a good thing? 

Also, this is easy to implement!! :)

Example Waveform:

   Begins: (0ns, 0.0V)
   Ends:   (9ns, 4.0V)
   Load:   50 Ohms, 0.0V

For 2% agreement, the v_tolerance = 2% * (4.0 - 0) = .08V

  So model passes if...

      -0.08 < v_dc_low_for_load < 0.08   

               AND

       3.92 < v_dc_high_for_load < 4.28

Is this reasonable?

-Chris R.

---

From: [email-masked] ( Bob Ross)
Date: Wed, 30 Oct 96 16:05 PST

Chris:

I think your assumptions are good.  Holding the endpoints to within 2% of the
difference between seems accurate enough for most cases.  The check may
fail with very heavily loaded devices.  However, we cannot be perfect for
all cases.  Will the percentage be adjustable?

Bob Ross
Interconnectix, Inc.