[SI-LIST] Re: IBIS model.
- From: Adam.Tambone@xxxxxxxxxxxxxxxxx
- To: signalguy@xxxxxxxxx
- Date: Mon, 20 Aug 2001 08:45:34 -0400
SignalDude,
The Power and Ground Clamp curves describe the amount of current that flows
through the ESD structures of a device when the voltage at the external
node of the buffer goes beyond Vcc or ground. Typically you would see zero
or near zero current until the voltage at the external node goes beyond the
rails, and if you were to superimpose the two curves you would typically
see the characteristic Zener diode curve. Essentially if the voltage at
the external node goes too far beyond the rails, consider the Power and
Ground Clamps to be current sources that will neutralize this voltage and
prevent these large spikes from entering and harming the device.
The Pullup and Pulldown curves describe the amount of current present at
the output when the device is in the logic high or logic low states. The
IBIS Checker will compare these curves to the transient Rising and Falling
waveforms to be sure the logic high and logic low levels for both sets of
curves are nearly equal. From what I understand this is accomplished by
dropping a load line across the DC ( pullup and pulldown ) curve defined by
the points (0V, Vcc/Rload A), (Vcc V, 0A) and dropping a perpendicular line
at the intersection to see what the operating point is and what the Voltage
across Rload is. This is then compared to the High or Low of the Rising or
Falling Waveforms. I hope I described that clearly. Hopefully there will
be some more responses to confirm or correct this. Good luck!
Adam Tambone
"fname lname" <signalguy@xxxxxxxxx>@freelists.org on 08/18/2001 08:15:27 PM
Please respond to signalguy@xxxxxxxxx
Sent by: si-list-bounce@xxxxxxxxxxxxx
To: si-list@xxxxxxxxxxxxx
cc:
Subject: [SI-LIST] IBIS model.
Hi Folks,
I have some basic questions about what is contained in an IBIS model.
What all information can I get from looking at the Power and Gnd Clamps.
Also how can I make sure the values under the pullup and pull down curves
are correct. Also what all information can be obtained from the VI curve.
regards,
Signalguy.
Get 250 color business cards for FREE!
http://businesscards.lycos.com/vp/fastpath/
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
