In any engineering situation to verify something, to ensure it is correct, you need a standard to verify against. In this case you need either the original SPICE or measurements of an actual device. Without either of these how can you verify? You can always use some engineering judgment to see if the curves look reasonable. I would look at the datasheet for the buffer as a place to start to base reasonableness on. Tom Dagostino Teraspeed(R) Labs 13610 SW Harness Lane Beaverton, OR 97008 503-430-1065 tom@teraspeed.com www.teraspeed.com Teraspeed Consulting Group LLC 121 North River Drive Narragansett, RI 02882 401-284-1827 -----Original Message----- From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org]On Behalf Of Indira Gazula Sent: Wednesday, August 17, 2005 11:52 AM To: Dekker Graden Cc: ibis-users@eda.org Subject: RE: [IBIS-Users] IBIS model check So effectively, in the absence of either spice curves or measurement data, I'm stuck with no way of verifying the IBIS model? Indira. -----Original Message----- From: Dekker Graden [mailto:dekker@teraspeed.com] Sent: Wednesday, August 17, 2005 11:27 AM To: Indira Gazula Subject: Re: [IBIS-Users] IBIS model check There are a couple of methods for checking. One is using the spice for the same part and seeing if the IV and VT curves match up. The other way is to take a real part and perform some measurements on it. Then conpair the measurement results to the IBIS file to see how closely they match up. Dekker Indira Gazula wrote: >Hi All, > >I have a general question: How does one check if the IBIS model provided has >correctly generated data. I ask this because, I was recently working on a >model which I thought was generationg unneccesarily high voltage levels >(point-to-point). To test I had just connected the IO model I had to itself, >without any interconnects in-between and found the voltages to be beyond the >spec levels. I understand that the model impedance might not be matched to >the load value the data was generated for, but was just wondering how one >could make sure. > >Regards, >Indira. > >-----Original Message----- >From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org]On >Behalf Of Muranyi, Arpad >Sent: Wednesday, August 17, 2005 9:43 AM >To: ibis-users@eda.org >Subject: RE: [IBIS-Users] Mixed-Signal Analog IO ? > > >If that's what you need to model a band gap device, >you can also consider a pair of IV curves in the >clamp tables. Those are always on, whether the >model drives or receives, and you can make a >voltage divider with two appropriately shaped and >sized IV curves. > >Arpad >=================================================== > >-----Original Message----- >From: Tom Dagostino [mailto:tom@teraspeed.com] >Sent: Wednesday, August 17, 2005 9:34 AM >To: Lars Snith; Muranyi, Arpad >Cc: ibis-users@eda.org >Subject: RE: [IBIS-Users] Mixed-Signal Analog IO ? > >... >... >... >For a voltage output like the output of a band gap reference make a voltage >divider using a terminator model whose values give you the Thevenin >equivalent for the output impedance of the part you are trying to model. > >|------------------------------------------------------------------ >|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 > > > |------------------------------------------------------------------ |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 1993Received on Wed Aug 17 12:22:12 2005
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