Subject: Re: [IBIS-Users] LVDS RECEIVER TERMINATION Question
From: Peter LaFlamme (plaflamm@amcc.com)
Date: Tue Jul 23 2002 - 06:46:04 PDT
Hi Adam,
Thanks for the interest and response. In regards to your question, one of the inputs can be left floating to get the pwr/gnd clamp info. The other part of the model will take care of the resistor termination and its variation over process.
Regards,
Peter
-- Peter LaFlammeApplied Micro Circuits Corp. System Applications Engineer 200 Minuteman Rd, 3rd Floor Andover, MA 01810
978-247-8470 phone 978-623-0055 Fax
Adam.Tambone@fairchildsemi.com wrote: > > Hello Peter, > > I have an additional question regarding what you have described below. If > the LVDS receiver has an internal 100 Ohm termination across two LVDS > inputs, then when the I-V measurements are taken for one input, how is the > partner input being treated? Is it left floating? > > Thaks, > Adam > > |---------+---------------------------> > | | Peter LaFlamme | > | | <plaflamm@amcc.c| > | | om> | > | | Sent by: | > | | owner-ibis-users| > | | @eda.org | > | | | > | | | > | | 07/23/02 09:01 | > | | AM | > | | | > |---------+---------------------------> > >-------------------------------------------------------------------------------------------------------------------------------| > | | > | To: ibis-users@eda.org | > | cc: | > | Subject: [IBIS-Users] LVDS RECEIVER TERMINATION Question | > >-------------------------------------------------------------------------------------------------------------------------------| > > Hi All, > I am tasked with creating an IBIS model for an LVDS receiver cell that has > an internal 100 ohm termination between the P and N nodes. I had asked Bob > Ross about this a while ago and as usual he was very helpful. From his > response I used the following > implementation: > > |**************************************************************** > | Component: LVDSRCV > |**************************************************************** > | > [Component] LVDSRCV > [Manufacturer] AMCC > | > | > | > [Package] > | variable typ min max > R_pkg 1E-3 NA NA > L_pkg 1E-9 NA NA > C_pkg 1E-12 NA NA > | > [Pin] signal_name model_name R_pin L_pin C_pin > 1 PAD lvdsrcv NA NA NA > 2 PADN lvdsrcv NA NA NA > | > [Series Pin Mapping] pin_2 model_name function_table_group > 1 2 rterm_100 > > | > [Diff_pin] inv_pin vdiff tdelay_typ tdelay_min > tdelay_max > | > 1 2 0.2 0 0 0 > > [Model] rterm_100 > C_comp 0.1pF 0.1pF 0.1pF > > Model_type Series > |variable R(typ) R(min) R(max) > [R Series] 100 80 120 > > [Temperature Range] 25.00 125.00 0.00 > [Voltage Range] 1.800 1.650 1.950 > > **************************************************************************************** > > I was able to get the model past the IBIS checker but my simulations did > not show the 100 ohm terminator. I was using a tool which I believe does > not support this implementation (no need to mention names). I have seen > other implementations where I believe > a "Dynamic clamp" is used to model the termination behavior, but I am > unsure. Can anyone guide me to some reference material or weigh in with > your experience or help. > > Thanks alot, > Peter > > -- > Peter LaFlamme > > Applied Micro Circuits Corp. > System Applications Engineer > 200 Minuteman Rd, 3rd Floor > Andover, MA 01810 > > 978-247-8470 phone > 978-623-0055 Fax > |------------------------------------------------------------------ > |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
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