RE: [IBIS-Users] Need clarification

Hi,
Here's how the VI curves are obtained:
If the driver has an enable input, a sweep is performed with the driver
disbled.
(This gives the performance of whatever clamping structures may be present.)
This curve is then subtracted from the curve obtained with the output
enabled, resulting in a curve that models the performance of only the driver
(i.e. it excludes the contributions made by the clamp structures).
    
The voltage range over which the subtraction is performed is different for
each curve: for a pullup curve, the subtraction is performed over the
voltage range defined by the power clamp curve, while for a pulldown curve,
the subtraction is performed over the voltage range defined by the ground
clamp curve.

My apologies for any confusion that my response generated.
-Ambrish.

Ambrish K Varma
akvarma@ncsu.edu
North Carolina State University
ph(919)513-2015, fax(919)515-2285

-----Original Message-----
From: Lynne Green [mailto:lgreen22@mindspring.com]
Sent: Thursday, September 09, 2004 12:33 PM
To: akvarma@ncsu.edu; ibis-users@eda.org
Subject: RE: [IBIS-Users] Need clarification

Hi, Ambrish,

Did you mean to say:

Pullup = total_current - power_clamp - gnd_clamp
Pulldown = total_current - power_clamp - gnd_clamp

- Lynne

"IBIS training when you need it, where you need it."

Dr. Lynne Green
Green Streak Programs
http://www.greenstreakprograms.com
425-788-0412
lgreen22@mindspring.com

-----Original Message-----
From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org] On Behalf
Of akvarma@ncsu.edu
Sent: Wednesday, September 08, 2004 6:16 AM
To: ibis-users@eda.org
Subject: Re: [IBIS-Users] Need clarification

Hi,
Both the pull-up and pull-down VI curves subtract the power and ground
clamp curves respectively to obtain the VI table in s2ibis2 and s2ibis3.
This is done only for models with enable inputs.
Hope that helps.
-Ambrish.

--Ambrish K Varma
North Carolina State University.

>
> Hi,
>
> I wanted to know how the VI table is generated in the IBIS file. Is
> the VI data generated by subtracting the both the power clamp and ground
> clamp currents from the pull up current? I wanted to have clarity on how
> exactly s2ibis script is generating the pull up data.
>
>
> Please answer the same
>
> Thanks and Regards,
> Radhika
>
>
>
>
> Confidentiality Notice
>
> The information contained in this electronic message and any attachments
> to this message are intended
> for the exclusive use of the addressee(s) and may contain confidential or
> privileged information. If
> you are not the intended recipient, please notify the sender at Wipro or
> Mailadmin@wipro.com immediately
> and destroy all copies of this message and any attachments.

|------------------------------------------------------------------
|For help or to subscribe/unsubscribe, email majordomo@eda.org
|with just 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 email a written request to ibis-request@eda.org.
|
|IBIS reflector archives exist under:
|
| http://www.eda.org/pub/ibis/email_archive/ Recent
| http://www.eda.org/pub/ibis/users_archive/ Recent
| http://www.eda.org/pub/ibis/email/ E-mail since 1993

|------------------------------------------------------------------
|For help or to subscribe/unsubscribe, email majordomo@eda.org
|with just 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 email a written request to ibis-request@eda.org.
|
|IBIS reflector archives exist under:
|
| http://www.eda.org/pub/ibis/email_archive/ Recent
| http://www.eda.org/pub/ibis/users_archive/ Recent
| http://www.eda.org/pub/ibis/email/ E-mail since 1993
Received on Thu Sep 9 10:35:50 2004