RE: [IBIS-Users] How is the switching edge response implemented in IBIS

Hi Yuancheng,
Generally Rise and Fall edges are determined with 2-VT tables(different Fixtures) using 2e-2q( 2 equations and two coefficient algorithm).
The correctness of this equation is not based on the Rise/fall time, but on the design.

1: Sometimes having 3/4 VT tables for each rise/fall help get better accuracy. When driver are big and Miller cap ( PAD to Gates) is High.
But that is dependents on your simulation tool. As I know HSPICE-2009 and above can handle Multiple VT tables.

2: If there is feedback circuit controlling the slew at the PAD, then you need to look at IBIS-AMS options.

These are few reasons I know. Understand the algorithm and your design.

Regards,
Muniswara

From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org] On Behalf Of ji xiao
Sent: Wednesday, April 20, 2011 9:13 AM
To: ibis-users
Subject: [IBIS-Users] How is the switching edge response implemented in IBIS

Dear Sir/Madam,
As I know, IBIS model has a VT table described the dynamic response of a buffer for the fastest switching edge.
However, if the input pulse has a quite long rise/fall time (much slower than its maximum switching rate), how is the IBIS model interpolate the response during the rise/fall period?
Thanks for your help!

Regards,
Yuancheng

--
This message has been scanned for viruses and
dangerous content by MailScanner<http://www.mailscanner.info/>, and is
believed to be clean.
-- IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.
--------------------------------------------------------------------
|For help or to subscribe/unsubscribe, e-mail majordomo@eda-stds.org
|with the appropriate command message(s) in the body:
|
|  help
|  subscribe   ibis       <optional e-mail address, if different>
|  subscribe   ibis-users <optional e-mail address, if different>
|  unsubscribe ibis       <optional e-mail address, if different>
|  unsubscribe ibis-users <optional e-mail address, if different>
|
|or e-mail a request to ibis-request@eda-stds.org.
|
|IBIS reflector archives exist under:
|
|  http://www.eda-stds.org/pub/ibis/email_archive/ Recent
|  http://www.eda-stds.org/pub/ibis/users_archive/ Recent
|  http://www.eda-stds.org/pub/ibis/email/         E-mail since 1993