Subject: RE: [IBIS-Users] pullup/pulldown range LVDS
From: Lynne Green (lgreen@cadence.com)
Date: Mon Aug 11 2003 - 10:06:06 PDT
Hello, Erik,
One would normally add one point at each end outside of the normal
operating
range (using the same current as the normal operating endpoint). This
only
"costs" two points of the 100 allowed in IBIS 3.2, so there is no
significant loss
in accuracy.
This does two things:
1) Allows the simulator tool to search the entire -Vcc,+2Vcc range when
performing convergence phase, resulting in faster convergence.
2) Allows the IBIS file to pass the IBIS parser.
| Example with 12mA end points in I-V data:
-3.3V -12m | dummy end point
0.4V -12m | end point of actual operating region
| normal data, up to 96 more lines
1.6V 12m | end point of actual operating region
6.6V 12m | dummy end point
Best regards,
Lynne
-----Original Message-----
From: erik.van.der.ven@philips.com [mailto:erik.van.der.ven@philips.com]
Sent: Monday, August 11, 2003 2:01 AM
To: ibis-users@eda.org
Subject: [IBIS-Users] pullup/pulldown range LVDS
Dear IBIS users,
For ECL the pullup/pulldown curves only have to cover the 0-2.2V range
(relative to Vcc). This is because of the limited voltage swing, which
is centered around a DC voltage far away from the supply rails.
How about LVDS? It has a similar output swing. Is it needed to cover the
"regular" voltage range of -3.3-6.6V (for 3.3V supply)? It's rather a
waste of accuracy for the typical operation area (less points remain).
With kind regards,
Ir. Erik van der Ven
Room DB1032
Business Line Networking Infrastructure
Philips Semiconductors BV
Gerstweg 2
6534 AE Nijmegen
The Netherlands
Phone: +31-24-3534334
|------------------------------------------------------------------
|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
This archive was generated by hypermail 2b28 : Mon Aug 11 2003 - 10:08:15 PDT