SPI-3 single-ended AC test circuit

Stefek, Steve sstefek at lsil.com
Tue Jun 29 13:17:59 PDT 1999


* From the T10 Reflector (t10 at symbios.com), posted by:
* "Stefek, Steve" <Steve.Stefek at lsil.com>
*
I notice that the SPI-2 Load circuit does not specify what frequency the
driver should be running at when the slew measurement is made.  On cables,
the slew rates will change depending on the frequency of the driving signal.
Was there an "intended" frequency to be used for single ended slew rate
measurements, or are slews relatively frequency independent on the SPI-2
load because it is not a transmission line.  

Also, can anyone remember why the specified rate is 520mv/ns?  Have data
failures been seen at a slew rate anywhere near this number?

Thanks,
Steve

-----Original Message-----
From: Gene_Milligan at notes.seagate.com
[mailto:Gene_Milligan at notes.seagate.com]
Sent: Friday, June 25, 1999 6:01 PM
To: John Lohmeyer
Cc: T10 Reflector; Barnes, Larry
Subject: Re: SPI-3 single-ended AC test circuit


* From the T10 Reflector (t10 at symbios.com), posted by:
* Gene_Milligan at notes.seagate.com
*
I recall that Kevin tried years ago to get the 15 pF raised to, I think,
>100 pF and it took vigilance to avoid this change. The argument for the
change was that the cable loading was much higher than 15 pF. The argument
against the change was that the 15 pF was the gold standard the slew rates
had been specd during the design phase.

Gene


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