[SI-LIST] Re: Issues with Midpoint Crossing of Differential IBIS Buffer


Hello Tim,

Here is a small tip that you might not have tried yet.  The 'ramp' keyword
associated with B-Elements in HSPICE specifies what V-t data to use.
ramp=0 uses ramp data, ramp=1 uses the first set of V-t data for rising and
falling waveforms, and ramp=2 uses two sets each of V-t data for rising and
falling waveforms.  Perhaps this will help.

Rgds,
Adam




|---------+---------------------------->
|         |           "Timothy Coyle"  |
|         |           <Timothy.Coyle@ns|
|         |           c.com>           |
|         |           Sent by:         |
|         |           si-list-bounce@fr|
|         |           eelists.org      |
|         |                            |
|         |                            |
|         |           07/31/02 10:02 AM|
|         |           Please respond to|
|         |           Timothy.Coyle    |
|         |                            |
|---------+---------------------------->
  
>-------------------------------------------------------------------------------------------------------------------------------|
  |                                                                             
                                                  |
  |        To:      si-list@xxxxxxxxxxxxx                                       
                                                  |
  |        cc:                                                                  
                                                  |
  |        Subject: [SI-LIST] Issues with Midpoint Crossing of Differential 
IBIS Buffer                                           |
  
>-------------------------------------------------------------------------------------------------------------------------------|




Hi,
I am having issues with a differential IBIS buffer. When I run the file in
XTK, it works fine. When I run the file in HSPICE, the midpoint crossing
is not correct. The transition
rate and waveshape of an individual driver are good, but the midpoint
crossing is towards Vcc.  I checked the V-T data to see if the
rising/falling data crossed at the
midpoint, and it does. I'm wondering if this is a problem with the I-V or
V-T data, or both? Or is this a simulator issue? Instead of using a
differential load resistor, I tied
the outputs to a load resistor to a reference voltage (Vos), and then the
midpoint crossing was accurate.
Any suggestions/comments?

Regards,
Tim


------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:
http://www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field

List archives are viewable at:
                         http://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

or to administer your membership from a web page, go to:
http://www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field

List archives are viewable at:     
                http://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: