SPI-3 single-ended AC test circuit

John Lohmeyer lohmeyer at ix.netcom.com
Fri Jun 25 09:07:22 PDT 1999

* From the T10 Reflector (t10 at symbios.com), posted by:
* John Lohmeyer <lohmeyer at ix.netcom.com>
For quite some time we have specified an AC test circuit for single-ended
that is rather unrealistic of actual bus loading.  Figure 27 in SPI-3 (PDF
page number 76) shows a 200 pF capacitor to ground with a 47 Ohm resistor
to a 2.5 volt source for measuring everything but slew rates, which use the
same circuit with a 15 pF capacitor.  

Does anyone remember why we used 200 pF for these measurements?  I would
think that it would be better if the test circuit load was closer to that
of an actual bus, say 30 pF.


John Lohmeyer                  Email: lohmeyer at ix.netcom.com
LSI Logic Corp.                Voice: +1-719-533-7560
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