Date: Mon Aug 18 2008 - 20:58:11 PDT
Hi Chetana, Slide-20 of the presentation in the link can help you, in correcting IV-VT mismatch. http://www.eda.org/ibis/summits/jan02/bell1.pdf This presentation discusses some more common errors and warnings. Thanks, Muniswar ________________________________ From: owner-ibis@eda.org [mailto:owner-ibis@eda.org] On Behalf Of Chetana Raghuwanshi Sent: Monday, August 18, 2008 7:21 PM To: Sudarshan H N Cc: ibis@eda.org; ibis-users@eda.org; owner-ibis-users@eda.org Subject: Re: [IBIS-Users] Re: [IBIS] Different PMOS and NMOS driver impedence Hi Sudarshan, You are right. My concern is IV VT mismatch error. How would it disappear by increasing the simulation time ? Best Regards Chetana -------------------------------------------------------- Chetana Raghuwanshi CTO / Process & Library Technology NXP Semiconductors India NXP Block C, 4th Floor MFAR Manyata Tech Park Nagavara, Bangalore-560045 Tel : +91 80 4024 7072 -------------------------------------------------------- "Sudarshan H N" <hn.sudarshan@gmail.com> "Sudarshan H N" <hn.sudarshan@gmail.com> Sent by: owner-ibis-users@server.eda.org 2008-08-18 06:43 PM To "Chetana Raghuwanshi" <chetana.raghuwanshi@nxp.com> cc ibis-users@server.eda.org, ibis@server.eda.org Subject [IBIS-Users] Re: [IBIS] Different PMOS and NMOS driver impedence Hello Chetana, You can use any of the 2 values for Rfixture to generate Vt curves. There is no rule that , your Rfixture should match to the PMOS or NMOS driver resistance. But you should always use one value to generate the one set of rising and falling waveforms(experts, correct me if i am wrong). If you are seeing any errors with respect to IV and Vt curve mismatch , just simulate for more time so that it will reach the saturation. Regards Sudarshan On Mon, Aug 18, 2008 at 6:37 PM, Chetana Raghuwanshi < chetana.raghuwanshi@nxp.com <mailto:chetana.raghuwanshi@nxp.com> > wrote: Hello Experts, One of my IO cell has a buffer with different PMOS and NMOS impedences. PMOS impedence is approx 200 Ohms and that for NMOS is 96 Ohms. In this case what should be the value of Rfixture for calculating IV VT curves ? Would it be Rfixture1 for calculating pull down and falling waveforms and Rfixture2 for calculating pull up and rising waveforms ? If I do rise/pullup and fall/pulldown simulations with different Rfixture values, is it acceptable ? Best Regards Chetana -- This message has been scanned for viruses and dangerous content by MailScanner <http://www.mailscanner.info/> , and is believed to be clean. -- This message has been scanned for viruses and dangerous content by MailScanner <http://www.mailscanner.info/> , and is believed to be clean. -- This message has been scanned for viruses and dangerous content by MailScanner <http://www.mailscanner.info/> , and is believed to be clean. -- 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
