Hi It depends very much on just how low a frequency sine wave you put into the limiter. If you run low enough, then indeed you will be able to see the difference. If the scope can display 1 ns jitter, then a 1 Hz sine wave is likely to be low enough.
Bob -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: Wednesday, August 22, 2012 5:55 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Understanding Oliver Collins Paper "Design of Low Jitter Hard Limiters" In your opinion, if I build a 7404 ZCD and a hard limiter one, can I see the jitter difference on a simple 'scope (Tek TDS220 or TDS3012) or do I need the Wavecrest SIA3000? On Wed, Aug 22, 2012 at 1:37 AM, Bob Camp <li...@rtty.us> wrote: > Hi > > Since the Collins approach "tunes" the system for a single frequency input > (more or less), the approach is probably not the best for a "many decades" > sort of frequency range. There are a number of things that he alludes to in > the paper, but does not directly address. The most obvious is the > temperature dependance of the "stuff" the system is made of. Another is the > simple fact that a non-clipping linear amplifier is likely the best choice > for a first stage, provide the input is not already near clipping. > > Bob > > On Aug 21, 2012, at 12:50 PM, raj_so...@agilent.com wrote: > > > Hello everyone, > > > > I am new to this forum. > > It looks like a lively discussion on various topics. > > > > A colleague of mine here at Agilent pointed me to this paper entitled > "The Design of Low Jitter Hard Limiters" by Oliver Collins. In Bruce > Griffiths' precision time in frequency webpage, this paper is described as > "seminal." > > (http://www.ko4bb.com/~bruce/ZeroCrossingDetectors.html) > > > > Since I'm trying to create a limiter that will accept frequencies > ranging from 1 MHz to 100 MHz, I thought it would be good to understand the > conclusions of this paper (if not the mathematics as well). The > mathematics turned out to be quite challenging to decode. Has someone on > this forum unraveled the equations? It appears Collins has recommendations > on the bandwidth and gain of a jitter minimizing limiter, and then extends > this analysis to provide the bandwidth and gain of a cascade of limiters. > But the application is still fuzzy. In figure 5, he shows a graph showing > the dependence of jitter on crossing time. Is the crossing time (implied > by equations 7) considered a design parameter one can vary? Also, on figure > 4, the "k" parameter has been varied to show the rising waveform as a > function of "k". The threshold is always assumed to be 0.5. So could "k" > be related to "tau", the time constant of the RC filter? > > > > Thanks in advance for all your help. > > > > Yours > > > > Raj > > > > > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.