is it possible to extract Vss and Vcc s-parameter respect to ideal reference? I doubt, any tool can do this kind of s-parameter extraction. if such s-parameter extraction is not possible. do you suggest to use RLC models of VCC and VSS based on quasi-static extraction (using Q3D) for SSN problem solution. Thanks On Wed, Oct 8, 2014 at 9:47 PM, Iliya Zamek <dmarc-noreply@xxxxxxxxxxxxx> wrote: > Hi Naresh, > Steve described in details many reasons why receiver might see a noise > when you applied in-phase noise to Vss and Vcc. It is also important to > know some more details about your experiments to make a conclusion. Whether > you were using oscilloscope, or receiver to measure output jitter and > noise, and how you applied noise to Vss and Vcc. In addition to Steve > observation, different "modulation sensitivity" of Vss and Vcc, the > pre-driver to the jitter contribution, and just simple conversion of > waveform' shift to the jitter, - all might contribute to the output jitter > and noise. I agree with you that I/O delay respect to the Vss "disturbance" > also one of the reason of remaining noise. > I also agree with you that it is good to extract both Vss and Vcc respect > to ideal reference, which is not so easy to simulate. However, if you can, > there is even more important reason to do so. If you have other signals > switching along with you measured, these others will contribute through > common Vss to the Vss noise. So, all depends on details how you applied > noise and did measurements. > Thank you.Iliya > On Tuesday, October 7, 2014 11:50 PM, Naresh Dhamija < > naresh.dhamija@xxxxxxxxxxxxx> wrote: > > > Hi Iliya, > > > I understand that different blocks inside IO will convert the in phase > noise to differential noise and will cause jitter within the IO, but at the > output of IO pad w.r.t noise vss, I see some noise, I guess it is because > of finite delay within the output stage of IO . Is this correct? > > > > If it is so, then my follow up question is: > > In the complete system simulation, when we plug package and board > s-parameter models, it is good to have both vddio and vss extracted w.r.t > ideal ground rather than only vddio extracted which will only have > differential noise of vddio with its local vss where common noise of vddio > and vss is missed out. > > > > Regards > > Naresh > > > > *From:* Iliya Zamek [mailto:i_zamek@xxxxxxxxx] > *Sent:* Wednesday, October 08, 2014 12:38 AM > *To:* naresh.dhamija@xxxxxxxxxxxxx; si-list@xxxxxxxxxxxxx > *Subject:* Re: [SI-LIST] Single ended Noise OR Differential Noise > > > > Hi Naresh, > > > > Your observation is correct. The impact of PDN noise on on-chip signals > timing and logic levels noise is different. The impact on I/O Jitter is > more complex. > > The impact on logic levels' noise does not depend on noise frequency and > I/O signal frequency interrelationship, but impact on I/O' Jitter does. You > might want to see the results of research of impact noise on Jitter in a > paper (and references) by Google: "On-chip Jitter and system Power > Integrity", I. Zamek, Designcon 2012 > > > > Also, there are two effects to consider at I/O Jitter analysis: impact on > Pre-Driver and impact on output Buffer. Impact on Pre-Driver contribute > mainly on Jitter, the impact on Buffer contributes on both, Jitter and > Logic levels' noise. You might see the research and experiments on I/O > jitter in reference #16: > > Zhe Li, Iliya Zamek, Peter Boyle, âFPGA IO Timing Variations with SSO > Noise,â DesignCon 2008 > > > > Thank you. > > > > Iliya Zamek > > > > > > On Tuesday, October 7, 2014 6:10 AM, Naresh Dhamija < > naresh.dhamija@xxxxxxxxxxxxx> wrote: > > > > Hi folks, > > I am doing power noise analysis on a system that uses SSTL IO buffers. I > am seeing the ripple on the IO output signal - such that during hi state > IO output signal follows the noise whatever is on the vddio and during low > state, IO output signal follows the noise on the vss. Observing this > phenomenon, I purposely forced IN PHASE single ended noise to both vdddio > and vss of almost the same frequency as of data rate but uncorrelated with > data rate. Since noise forced to vddio and vss are IN PHASE so > Differential Noise measured between vddio and vss at each instant shows > zero noise. But still I see jitter on the edges because of finite rise and > fall times, the initial low level and final high level for a transition > from low to hi are not always same. Does this mean that along with > differential noise, single ended noise on power and ground also cause > jitter to IO driver. > > Regards > Naresh > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > List forum is accessible at: > http://tech.groups.yahoo.com/group/si-list > > List archives are viewable at: > //www.freelists.org/archives/si-list > > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > List forum is accessible at: > http://tech.groups.yahoo.com/group/si-list > > List archives are viewable at: > //www.freelists.org/archives/si-list > > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > > > > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > List forum is accessible at: > http://tech.groups.yahoo.com/group/si-list > > List archives are viewable at: > //www.freelists.org/archives/si-list > > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > > -- Thanks Sanjeev ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List forum is accessible at: http://tech.groups.yahoo.com/group/si-list List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu