Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Hi Thanks to all the information here. I can put more items to my experiment list. Regads Li Ang, BI7LNQ 2016-01-11 11:28 GMT+08:00 Magnus Danielson : > Moin, > > On 01/10/2016 07:56 PM, Attila Kinali wrote: > >> On Sun, 10 Jan 2016 14:30:41 +0100 >> Magnus Danielson wrote: >> >> SR-flipflop? Are you refering to the JK-FF phase detector or the PFD? >>> >>> A straight SR-flipflop. I would have written JK-FF or PFD if I meant it. >>> Also, as I mentioned the PFD directly after, you could have concluded >>> that was not what I intended. >>> >>> A SR-flip-flop with no illegal input states is easy to build from a >>> 74HC00. >>> >> >> The illegal input states were my concern, indeed. And a quick google >> didn't show up anything to disperse thesenot until I started reading >> the 4046 datasheet in detail. >> > > That's one place to look yes. > > But there is one thing about the arangement of the SR FF in the 4046[1] >> that bothers me: >> Although S = R = 1 is valid, it does lead to the output oscillating >> between 0 and 1. >> > > Well, the dynamics of the gates will convert the rising edges on S and R > into short pulses before hitting the SR core. That is what the additional > AND gates does if you look at figure 1. > > The pulses on Sd and Rd will be about three gate-delays long. > > If the Sd and Rd '1' pulses overlap, then it becomes a bit hairer to > analyze the stability. > > However, this works pretty well in reality. Rather than having the +/- 90 > degree property of the XOR gate (which has a triangle phase-response, which > doesn't always is helpful) it has a +/- 180 degree sawtooth phase-response. > > Cheers, > Magnus > > ___ > 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Moin, On 01/10/2016 07:56 PM, Attila Kinali wrote: On Sun, 10 Jan 2016 14:30:41 +0100 Magnus Danielson wrote: SR-flipflop? Are you refering to the JK-FF phase detector or the PFD? A straight SR-flipflop. I would have written JK-FF or PFD if I meant it. Also, as I mentioned the PFD directly after, you could have concluded that was not what I intended. A SR-flip-flop with no illegal input states is easy to build from a 74HC00. The illegal input states were my concern, indeed. And a quick google didn't show up anything to disperse thesenot until I started reading the 4046 datasheet in detail. That's one place to look yes. But there is one thing about the arangement of the SR FF in the 4046[1] that bothers me: Although S = R = 1 is valid, it does lead to the output oscillating between 0 and 1. Well, the dynamics of the gates will convert the rising edges on S and R into short pulses before hitting the SR core. That is what the additional AND gates does if you look at figure 1. The pulses on Sd and Rd will be about three gate-delays long. If the Sd and Rd '1' pulses overlap, then it becomes a bit hairer to analyze the stability. However, this works pretty well in reality. Rather than having the +/- 90 degree property of the XOR gate (which has a triangle phase-response, which doesn't always is helpful) it has a +/- 180 degree sawtooth phase-response. Cheers, Magnus ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Am 10.01.2016 um 22:47 schrieb Alexander Pummer: and there was also a frequency/phase detector from Analog Devices, which took care about that dead zone AD9901. 73 KJ6UHN Alex 73, Gerhard, DK4XP ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
and there was also a frequency/phase detector from Analog Devices, which took care about that dead zone 73 KJ6UHN Alex On 1/10/2016 10:53 AM, Richard (Rick) Karlquist wrote: Phase frequency detectors (starting with the legendary MC4044) being made out of flip flops, had metastability and/or race conditions. Motorola showed a block diagram made of gates, as if it were combinatorial logic, but because of the feedback, it is actually a state machine, as described in the MC4044 data sheet. It had a dead zone around zero phase that came to light when Fairchild introduced the competing 11C44 PFD using Eric Breeze's patent to fix the dead zone. The 11C44 data sheet showed their dead zone, vs Brand M. Even that improved chip still had a "funny" zone, it just never went to zero gain. Fast forward to today, we are now seeing PFD's made with samplers. They too have a bunch of issues with phase noise floors. None of them come close to a mixer. In the 5071A, I used a mixer as a phase detector that had some flip flops only used for acquisition, so they were non players in terms of phase noise. I still think I would do that even if I had to do over 25 years later. Rick Karlquist N6RK ___ 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. - No virus found in this message. Checked by AVG - www.avg.com Version: 2016.0.7294 / Virus Database: 4489/11369 - Release Date: 01/10/16 ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
"generate stable high -frequency signals with d flip-flops as digital mixers ans all -IC low frequency phase -locked loop", by R.Treadway and L.J. Reed, page 78 Electronic design 1 January 1972 Resistot array denounces D flip-flop mixer page 184 EDN 12 April 1990 digital frequency subtract or EDN 1 April 1981 Kamil Kraus: Die Arbeitsweise eines einfachen Digitalmischer, Seite 72 Elektronik Heft 24, 1980 a very good explanation of the function of the digital mixer-- in German Design ideas; D flip-flop sutracs frequencies by Richard Kochis, Hewlett-PackardCo Ft. Collins ,CO, Gerald Flachs , New Mexico State University, Las Cruces, END 15 April, 10981 page 149 Robert a Pease National Semiconductor Corp : Four ICs subtract frequencies, EDN 1 April 1981 "Digitalis keverofokozat tervezese", Zombay Frerenc, Radiotechnika, Seite 244 # 5 1996, a complete design of the digital mixer with detailed theory and example in three consecutive issue of the magazine Radiotechnika -- in Hungarian. By using that literature I designed many frequency synthesizers containing D flip-flops as a digital mixer 73 KJ6 UHN Alex [alias Dr.Dipl.Ing. Alexander Pummer, PCS Consultants] US patents: many if you are interested I will send you a list On 1/10/2016 10:56 AM, Attila Kinali wrote: On Sun, 10 Jan 2016 14:30:41 +0100 Magnus Danielson wrote: SR-flipflop? Are you refering to the JK-FF phase detector or the PFD? A straight SR-flipflop. I would have written JK-FF or PFD if I meant it. Also, as I mentioned the PFD directly after, you could have concluded that was not what I intended. A SR-flip-flop with no illegal input states is easy to build from a 74HC00. The illegal input states were my concern, indeed. And a quick google didn't show up anything to disperse thesenot until I started reading the 4046 datasheet in detail. But there is one thing about the arangement of the SR FF in the 4046[1] that bothers me: Although S = R = 1 is valid, it does lead to the output oscillating between 0 and 1. Attila Kinali [1] Ti CD74HC4046A Datasheet http://www.ti.com/lit/ds/symlink/cd54hc4046a.pdf ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Phase frequency detectors (starting with the legendary MC4044) being made out of flip flops, had metastability and/or race conditions. Motorola showed a block diagram made of gates, as if it were combinatorial logic, but because of the feedback, it is actually a state machine, as described in the MC4044 data sheet. It had a dead zone around zero phase that came to light when Fairchild introduced the competing 11C44 PFD using Eric Breeze's patent to fix the dead zone. The 11C44 data sheet showed their dead zone, vs Brand M. Even that improved chip still had a "funny" zone, it just never went to zero gain. Fast forward to today, we are now seeing PFD's made with samplers. They too have a bunch of issues with phase noise floors. None of them come close to a mixer. In the 5071A, I used a mixer as a phase detector that had some flip flops only used for acquisition, so they were non players in terms of phase noise. I still think I would do that even if I had to do over 25 years later. Rick Karlquist N6RK ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
On Sun, 10 Jan 2016 14:30:41 +0100 Magnus Danielson wrote: > > SR-flipflop? Are you refering to the JK-FF phase detector or the PFD? > > A straight SR-flipflop. I would have written JK-FF or PFD if I meant it. > Also, as I mentioned the PFD directly after, you could have concluded > that was not what I intended. > > A SR-flip-flop with no illegal input states is easy to build from a 74HC00. The illegal input states were my concern, indeed. And a quick google didn't show up anything to disperse thesenot until I started reading the 4046 datasheet in detail. But there is one thing about the arangement of the SR FF in the 4046[1] that bothers me: Although S = R = 1 is valid, it does lead to the output oscillating between 0 and 1. Attila Kinali [1] Ti CD74HC4046A Datasheet http://www.ti.com/lit/ds/symlink/cd54hc4046a.pdf -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world is of no use without that foundation. -- Miss Matheson, The Diamond Age, Neil Stephenson ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Hi > On Jan 10, 2016, at 5:32 AM, Attila Kinali wrote: > > Moin phk! > > On Sat, 09 Jan 2016 22:56:27 + > "Poul-Henning Kamp" wrote: > >>> Single gate chips better than multi gate chips. >>> (no interference through the power supply of the different sub-parts) >> >> Would paralleing multiple gates in the same chip make things >> better or worse ? > > Good question. I have no idea. > > My first guess would be, that it would only give a slight improvement, > if at all. > > The reasoning is the following: > Under the assumption that the noise of all gates is ergodic and stationary, > then averaging the outputs of the gates should reduce the output noise. > > But the noise is not truly ergodic and there will be coupling between the > gates (both through the power supply and the outputs), that will change the > noise properties of the gates. Which in turn might lead to positive > interference > of the noise, instead of averaging out. > > But I have to admit that noise in electronic circuits is for me still > something very unintuitive. And I am more often wrong than right, when > it comes to predicting noise behavior. How do the gate outputs combine? Often the “pull down” part of the gate is stronger than the “pull up” part of the gate. If that’s what happens, you get an odd voting process rather than an average …. ( one gate says low, two gates say high, we go low ….) Bob > > Attila Kinali > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson > ___ > 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
God eftermiddag, On 01/10/2016 11:21 AM, Attila Kinali wrote: God morgon, On Sat, 9 Jan 2016 23:01:31 +0100 Magnus Danielson wrote: A D-Flipflop is a rather weird mixer. I have not done the calculation, but i'm pretty sure that the output is not exactly what you'd expect it from a normal mixer (namely having half the energy at the frequeny difference and half at the sum). It's not that wierd. It's a sampler, and thus it acts like a mixer as if the signal is spikes, which is just another interpretation of the Nyquist frequency aliasing. Meta-stability however creates an "interesting" aspect. Ah right! That also explains my uneasy feeling about it :-) It's relatively easy to get around metastabilitiy: just add another couple of D-flipflops in series. Unfortunately, that will only fix the metastable lingering in-between. It wont fix the edge being at the wrong time. Indeed. The second DFF will reduce the noise induced by the meta-stability. A small average shift in phase due to average meta-stability time-shift isn't usually a bit problem. However, it's down-mixing abilities is relatively straight-forward. A third digital phase-detector is the SR flip-flop. It avoids the 180 degree phase property (really a triangle wave signal) of the XOR, but give a 360 degree phase sawtooth. This can be helpful in certain lock-up conditions. SR-flipflop? Are you refering to the JK-FF phase detector or the PFD? A straight SR-flipflop. I would have written JK-FF or PFD if I meant it. Also, as I mentioned the PFD directly after, you could have concluded that was not what I intended. A SR-flip-flop with no illegal input states is easy to build from a 74HC00. The phase-frequency detector of the 4046 and the like has additional flip-flops to remember slipped cycles and forcing the frequency to regain that. Those provide a strong frequency lock mechanism with a phase detector in one. Interesting... i have to look into the old datasheets. It's really several SR flip-flops interconnected. It's intended to simplify design with a "digital" core, it aids in frequency lock as it pulls the integrator cap in the right direction stronger than the weak beating does on a distance in frequency difference. This way, you improve locking time for simple designs. There is other ways to aid the loop known to the professional. Single gate chips better than multi gate chips. (no interference through the power supply of the different sub-parts) Well, you should wire the other parts into passive mode. That would be a waste of good PCB space ;-) No. If you add noise through the other parts of the same chip, you will waste more PCB space to work around it. Cheers, Magnus ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
On 01/10/2016 11:32 AM, Attila Kinali wrote: Moin phk! On Sat, 09 Jan 2016 22:56:27 + "Poul-Henning Kamp" wrote: Single gate chips better than multi gate chips. (no interference through the power supply of the different sub-parts) Would paralleing multiple gates in the same chip make things better or worse ? Good question. I have no idea. My first guess would be, that it would only give a slight improvement, if at all. The reasoning is the following: Under the assumption that the noise of all gates is ergodic and stationary, then averaging the outputs of the gates should reduce the output noise. But the noise is not truly ergodic and there will be coupling between the gates (both through the power supply and the outputs), that will change the noise properties of the gates. Which in turn might lead to positive interference of the noise, instead of averaging out. But I have to admit that noise in electronic circuits is for me still something very unintuitive. And I am more often wrong than right, when it comes to predicting noise behaviour. Signals couples so nicely through power-pins, as the parasitic inductance work on them. This is also known as ground-bounce. It will limit the properties, and already have. In some counters, it was "convenient" from a layout perspective to use a double-comparator. The ground-bounce formed one of the main limiting factors, so in the next generation they used single comparators and a few other tricks and could half the noise-limits of the counter. Few "chips" (rather chip packages) includes internal decoupling caps, but it has started to appear for some of the larger onces as it is the only way to avoid the issues while pushing speed upwards. If you feed the same signal to the different XOR gates in the same package, wiring might cause some spread, but ground-bounce would connect them such that "late" gates would be encouraged by "early" gates. It will not be so "independent" anymore. Sometimes this cross-talk can work for you, but often against you. Unless you know exactly what you are doing, isolation is a good thing. Cheers, Magnus ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Moin phk! On Sat, 09 Jan 2016 22:56:27 + "Poul-Henning Kamp" wrote: > >Single gate chips better than multi gate chips. > >(no interference through the power supply of the different sub-parts) > > Would paralleing multiple gates in the same chip make things > better or worse ? Good question. I have no idea. My first guess would be, that it would only give a slight improvement, if at all. The reasoning is the following: Under the assumption that the noise of all gates is ergodic and stationary, then averaging the outputs of the gates should reduce the output noise. But the noise is not truly ergodic and there will be coupling between the gates (both through the power supply and the outputs), that will change the noise properties of the gates. Which in turn might lead to positive interference of the noise, instead of averaging out. But I have to admit that noise in electronic circuits is for me still something very unintuitive. And I am more often wrong than right, when it comes to predicting noise behaviour. Attila Kinali -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world is of no use without that foundation. -- Miss Matheson, The Diamond Age, Neil Stephenson ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
God morgon, On Sat, 9 Jan 2016 23:01:31 +0100 Magnus Danielson wrote: > > A D-Flipflop is a rather weird mixer. I have not done the calculation, > > but i'm pretty sure that the output is not exactly what you'd expect > > it from a normal mixer (namely having half the energy at the frequeny > > difference and half at the sum). > > It's not that wierd. It's a sampler, and thus it acts like a mixer as if > the signal is spikes, which is just another interpretation of the > Nyquist frequency aliasing. Meta-stability however creates an > "interesting" aspect. Ah right! That also explains my uneasy feeling about it :-) It's relatively easy to get around metastabilitiy: just add another couple of D-flipflops in series. Unfortunately, that will only fix the metastable lingering in-between. It wont fix the edge being at the wrong time. > A third digital phase-detector is the SR flip-flop. It avoids the 180 > degree phase property (really a triangle wave signal) of the XOR, but > give a 360 degree phase sawtooth. This can be helpful in certain lock-up > conditions. SR-flipflop? Are you refering to the JK-FF phase detector or the PFD? > The phase-frequency detector of the 4046 and the like has additional > flip-flops to remember slipped cycles and forcing the frequency to > regain that. Those provide a strong frequency lock mechanism with a > phase detector in one. Interesting... i have to look into the old datasheets. > > Single gate chips better than multi gate chips. > > (no interference through the power supply of the different sub-parts) > > Well, you should wire the other parts into passive mode. That would be a waste of good PCB space ;-) Attila Kinali -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world is of no use without that foundation. -- Miss Matheson, The Diamond Age, Neil Stephenson ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Hi > On Jan 9, 2016, at 3:25 PM, Attila Kinali wrote: > >> > > Generally speaking: Faster CMOS better than slower CMOS in terms of phase > noise. > (Though, I have yet to see actual measurements of this) The gotcha is that each family gets measured as the parts come out. Thus the data is spread out over about a 40+ year period. Most of it was taken down in log books off of a screen …. Bob > > Single gate chips better than multi gate chips. > (no interference through the power supply of the different sub-parts) > > > Attila Kinali > > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson > ___ > 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Attila, On 01/09/2016 09:25 PM, Attila Kinali wrote: On Sat, 9 Jan 2016 10:19:05 +0800 Li Ang wrote: In some article, I see people use a D-flipflop to sample the input signal with reference clock. When you want implement a mixer what's the difference between D-flipflop and XOR gate? A D-Flipflop is a rather weird mixer. I have not done the calculation, but i'm pretty sure that the output is not exactly what you'd expect it from a normal mixer (namely having half the energy at the frequeny difference and half at the sum). It's not that wierd. It's a sampler, and thus it acts like a mixer as if the signal is spikes, which is just another interpretation of the Nyquist frequency aliasing. Meta-stability however creates an "interesting" aspect. An XOR gate on the other hand, produces a very nice spectrum, given you input two clean square wave signals. Indeed. An interesting variant of the XOR gate as being used as a mixer is when you build a rubidium. One synthesis approach being used is to divide the 5 MHz OCXO signal with 16 to get 312,5 kHz. Then XORing it with 5 MHz produces as one of it's mirror signals 5,3125 MHz which is then fed with a step-up signal of 60 MHz or 90 MHz into the SDR diode in the cavity. A third digital phase-detector is the SR flip-flop. It avoids the 180 degree phase property (really a triangle wave signal) of the XOR, but give a 360 degree phase sawtooth. This can be helpful in certain lock-up conditions. The phase-frequency detector of the 4046 and the like has additional flip-flops to remember slipped cycles and forcing the frequency to regain that. Those provide a strong frequency lock mechanism with a phase detector in one. When you refer high speed CMOS XOR gate, do you mean 74LVC1G86? Generally speaking: Faster CMOS better than slower CMOS in terms of phase noise. (Though, I have yet to see actual measurements of this) Single gate chips better than multi gate chips. (no interference through the power supply of the different sub-parts) Well, you should wire the other parts into passive mode. Cheers, Magnus ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
In message <20160109212523.39180e2b7a788fe1ee2d7...@kinali.ch>, Attila Kinali writes: >Single gate chips better than multi gate chips. >(no interference through the power supply of the different sub-parts) Would paralleing multiple gates in the same chip make things better or worse ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
On Sat, 9 Jan 2016 10:19:05 +0800 Li Ang wrote: > In some article, I see people use a D-flipflop to sample the input > signal with reference clock. When you want implement a mixer what's the > difference between D-flipflop and XOR gate? A D-Flipflop is a rather weird mixer. I have not done the calculation, but i'm pretty sure that the output is not exactly what you'd expect it from a normal mixer (namely having half the energy at the frequeny difference and half at the sum). An XOR gate on the other hand, produces a very nice spectrum, given you input two clean square wave signals. > Acorrding to my understanding, > to multiply 1bit with another, I should use an AND gate, right? If you think of the signals as digital in the computational sense, with "high" representing "1" and "low" representing "0" then yes. But in signal theory, it's more appropriate to think of signals as "high" representing "+1" and low representing "-1". In the latter case, the XOR is the multiplicative element, and not the AND gate. > When you refer high speed CMOS XOR gate, do you mean 74LVC1G86? Generally speaking: Faster CMOS better than slower CMOS in terms of phase noise. (Though, I have yet to see actual measurements of this) Single gate chips better than multi gate chips. (no interference through the power supply of the different sub-parts) Attila Kinali -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world is of no use without that foundation. -- Miss Matheson, The Diamond Age, Neil Stephenson ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Hi You can use a D flip flop to sample (down convert) a signal. You may or may not get into metastability problems when you do. If you treat the gate inputs as -1 and +1 rather than 0 and 1, the XOR is a multiplier. If you put two signals into the gate and look at the output on a spectrum analyzer, you get the expected multiplier output. The *why* of the -1 and +1 stuff is something I will leave to others. It’s a bit involved. The 74LVC is a good series to use. The NC7SZ series is also a good one. In both cases, you will get a better noise floor at 5.5 V than at 3 V. Bob > On Jan 8, 2016, at 9:19 PM, Li Ang wrote: > > Hi Bob, >In some article, I see people use a D-flipflop to sample the input > signal with reference clock. When you want implement a mixer what's the > difference between D-flipflop and XOR gate? Acorrding to my understanding, > to multiply 1bit with another, I should use an AND gate, right? >When you refer high speed CMOS XOR gate, do you mean 74LVC1G86? > > Thanks > > BI7LNQ > > > 2016-01-09 6:42 GMT+08:00 Bob Camp : > >> Hi >> >> The board I have uses high speed CMOS single gate XOR’s. They have a >> pretty good >> phase noise floor (-170’s) so they should be pretty reasonable. >> >> Bob >> >>> On Jan 8, 2016, at 12:16 PM, Richard (Rick) Karlquist < >> rich...@karlquist.com> wrote: >>> >>> >>> >>> On 1/7/2016 3:11 PM, Bob Camp wrote: Hi If your intention is to run a mixer with saturated inputs …. just run an X-OR gate. It will handle the high level signals much better than an over-driven analog part. >>> Bob >>> >>> If you look at the schematic of an XOR gate IC and compare it >>> to the schematic of, for example, an MC1496 mixer, you will >>> see a lot of similarity. If the gate is of the ECL type, >>> it will have the addition of emitter followers, but that >>> it a minor detail of implementation. I'm not sure there >>> is a huge difference. ECL is a great logic family in >>> general (self-confessed ECL-phile here :-) but it is >>> probably the worst for phase noise, compared to the >>> saturating logic types. >>> >>> Rick Karlquist N6RK >>> ___ >>> 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Hi Bob, In some article, I see people use a D-flipflop to sample the input signal with reference clock. When you want implement a mixer what's the difference between D-flipflop and XOR gate? Acorrding to my understanding, to multiply 1bit with another, I should use an AND gate, right? When you refer high speed CMOS XOR gate, do you mean 74LVC1G86? Thanks BI7LNQ 2016-01-09 6:42 GMT+08:00 Bob Camp : > Hi > > The board I have uses high speed CMOS single gate XOR’s. They have a > pretty good > phase noise floor (-170’s) so they should be pretty reasonable. > > Bob > > > On Jan 8, 2016, at 12:16 PM, Richard (Rick) Karlquist < > rich...@karlquist.com> wrote: > > > > > > > > On 1/7/2016 3:11 PM, Bob Camp wrote: > >> Hi > >> > >> If your intention is to run a mixer with saturated inputs …. just run > >> an X-OR gate. It will handle the high level signals much better than > >> an over-driven analog part. > > > >> Bob > >> > > > > If you look at the schematic of an XOR gate IC and compare it > > to the schematic of, for example, an MC1496 mixer, you will > > see a lot of similarity. If the gate is of the ECL type, > > it will have the addition of emitter followers, but that > > it a minor detail of implementation. I'm not sure there > > is a huge difference. ECL is a great logic family in > > general (self-confessed ECL-phile here :-) but it is > > probably the worst for phase noise, compared to the > > saturating logic types. > > > > Rick Karlquist N6RK > > ___ > > 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Hi The board I have uses high speed CMOS single gate XOR’s. They have a pretty good phase noise floor (-170’s) so they should be pretty reasonable. Bob > On Jan 8, 2016, at 12:16 PM, Richard (Rick) Karlquist > wrote: > > > > On 1/7/2016 3:11 PM, Bob Camp wrote: >> Hi >> >> If your intention is to run a mixer with saturated inputs …. just run >> an X-OR gate. It will handle the high level signals much better than >> an over-driven analog part. > >> Bob >> > > If you look at the schematic of an XOR gate IC and compare it > to the schematic of, for example, an MC1496 mixer, you will > see a lot of similarity. If the gate is of the ECL type, > it will have the addition of emitter followers, but that > it a minor detail of implementation. I'm not sure there > is a huge difference. ECL is a great logic family in > general (self-confessed ECL-phile here :-) but it is > probably the worst for phase noise, compared to the > saturating logic types. > > Rick Karlquist N6RK > ___ > 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
On 1/7/2016 3:11 PM, Bob Camp wrote: Hi If your intention is to run a mixer with saturated inputs …. just run an X-OR gate. It will handle the high level signals much better than an over-driven analog part. Bob If you look at the schematic of an XOR gate IC and compare it to the schematic of, for example, an MC1496 mixer, you will see a lot of similarity. If the gate is of the ECL type, it will have the addition of emitter followers, but that it a minor detail of implementation. I'm not sure there is a huge difference. ECL is a great logic family in general (self-confessed ECL-phile here :-) but it is probably the worst for phase noise, compared to the saturating logic types. Rick Karlquist N6RK ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Hi If your intention is to run a mixer with saturated inputs …. just run an X-OR gate. It will handle the high level signals much better than an over-driven analog part. Yes *somebody* should check out a board built that way …. I’ll let you know when I do. Bob > On Jan 7, 2016, at 7:35 AM, Attila Kinali wrote: > > On Wed, 6 Jan 2016 18:30:07 -0800 > "Richard (Rick) Karlquist" wrote: > >> Read Gilbert's paper or Gray and Meyers analog IC textbook and >> you will see that the whole theory of operation of these >> depends on keeping the signal levels in them very small, >> especially if linearity (actually translinearity) is >> important. They always have current sources in the >> emitters that contribute a lot of noise. So you have >> small signals and large noise. The IC's that are >> designed to be DC coupled have even more sources of >> extra noise. > > How about using the Gilbert Cell as "digital" mixer, > ie driving the currents hard from one branch to the other > and replacing the current sources by resistors? > > How much would that improve the noise? Would it be still much > worse than the diode mixer? > > Attila Kinali > > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson > ___ > 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
On 2016-01-07 13:35, Attila Kinali wrote: On Wed, 6 Jan 2016 18:30:07 -0800 "Richard (Rick) Karlquist" wrote: Read Gilbert's paper or Gray and Meyers analog IC textbook and you will see that the whole theory of operation of these depends on keeping the signal levels in them very small, especially if linearity (actually translinearity) is important. They always have current sources in the emitters that contribute a lot of noise. So you have small signals and large noise. The IC's that are designed to be DC coupled have even more sources of extra noise. How about using the Gilbert Cell as "digital" mixer, ie driving the currents hard from one branch to the other and replacing the current sources by resistors? How much would that improve the noise? Would it be still much worse than the diode mixer? I think so. I checked up the MC1496 (just a sample-point of a classic Gilbert cell chip), it has 25 mV Peak, or -22 dBm as maximum input voltage before it starts to compress. Looking at the VCWR curves it is clear that it starts to misbehave there. Comparing that to the SBL-1+ double-balanced mixer (another random sample-point), which has an LO max of +7 dBm, you are looking at a difference of about 30 dB (29 to be exact, but neither number is exact to the 1 dB so). The MC1495, which is a linearized variant of the MC1496 (only true to some degree, it's more complex than that), allows 5 V signals easily, but internally you then go down to about the same levels. So, while you can drive things harder, you can do that on both sides. If it where less of a difference I'd say it would not be such a big difference, but it is relatively large difference here. Anyway, just wanted to put a few numbers down to illustrate the difference. Cheers, Magnus ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
On 1/7/2016 4:35 AM, Attila Kinali wrote: How about using the Gilbert Cell as "digital" mixer, ie driving the currents hard from one branch to the other and replacing the current sources by resistors? How much would that improve the noise? Would it be still much worse than the diode mixer? Attila Kinali You can drive the Gilbert cell as hard as you want, but the active region is only about 100 mv so the extra drive voltage doesn't help. It is the same as if you drove it with a 100 mV square wave. Somewhat better than a sine wave, but not a game changer. You can of course try to replace the emitter current source with a resistor, which works to the extent that you can afford to throw away voltage across the resistor, but you will never get a very high impedance. No OTS IC's are designed this way. What would be better would be to use an inductor. A true noiseless current source. Again no OTS IC's are designed this way. You would have to homebrew the whole mixer from discretes. Rick Karlquist N6RK ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
On 1/5/2016 12:07 PM, Bruce Griffiths wrote: The noise of such Gilbert cell based analog multipliers far exceeds that of the traditional mixer. Bruce Read Gilbert's paper or Gray and Meyers analog IC textbook and you will see that the whole theory of operation of these depends on keeping the signal levels in them very small, especially if linearity (actually translinearity) is important. They always have current sources in the emitters that contribute a lot of noise. So you have small signals and large noise. The IC's that are designed to be DC coupled have even more sources of extra noise. IMHO, they only make sense in low performance applications where the lack of transformers is important or in DC coupled applications. The only time I have used an analog multiplier IC was in Costas loop to demodulate QPSK from weather satellite. It needed to be DC coupled. Rick Karlquist N6RK On Wednesday, 6 January 2016 9:01 AM, Poul-Henning Kamp wrote: My little HP5065 project is continually running into the jitter of my HP5370B counter which is annoying me, so I'm looking int DMTD. Everybody seems to be using traditional diode-mixers for DMTD, and to be honest I fail to see the attraction. Why wouldn't a analog multiplier like AD835 be better idea ? What am I overlooking ? ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Yes must have been a year or so ago there was a thread I recall that someone was doing that. Thats one expensive approach to the problem. Regards Paul WB8TSL On Wed, Jan 6, 2016 at 2:37 PM, Bruce Hunter via time-nuts < time-nuts@febo.com> wrote: > I realize this would not measure frequency or phase difference; but has > anyone used a lock-in amplifier to compare two 10 MHz signals -- for > example to adjust a rubidium oscillator to agree with a GPS reference? > > Bruce, KG6OJI > ___ > 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Sorry I was under the impression I was replying to Don's post. Sometimes my Windows machine seems to mess up the part of the thread to which I thought I was replying. My Linux box doesn't seem to have this problem. Bruce On Tuesday, January 05, 2016 09:26:14 PM Charles Steinmetz wrote: > Bruce wrote: > >You mean DMTD = dual mixer time differencenotDDMTD = Digital dual > >mixer timer difference.The latter uses a pair of synchronisers / > >shift registers instead of a pair of mixers. > > I don't see how your comment is relevant to my post -- I did not > mention either DMTDs or DDMTDs. I only noted that the AD835 is > noisier than a diode mixer, although not as noisy as many analog > multipliers -- and that some noise improvement has been demonstrated > by using parallel multipliers. > > Charles > > >On Wednesday, 6 January 2016 12:03 PM, Charles Steinmetz > > > > wrote: > > Poul-Henning wrote: > > >My little HP5065 project is continually running into the jitter of > > >my HP5370B counter which is annoying me, so I'm looking int DMTD. > > > > > >Everybody seems to be using traditional diode-mixers for DMTD, > > >and to be honest I fail to see the attraction. > > > > > >Why wouldn't a analog multiplier like AD835 be better idea ? > > > > > >What am I overlooking ? > > > >You could have mentioned any of dozens of popular analog multipliers, > >and the answer would have been, "because they are way too > >noisy." The AD835 is also substantially noisier than diode mixers, > >but it at least begins to bridge the gap. The folks at CERN have > >been improving phase detector S/N by averaging the output of several > >AD835s for the TPMON project, with promising results. There is a > >preliminary report in "EUROTeV Report 2006-005-1." > > > >See also: > > > >RF-based electron beam timing measurement with sub-10fs resolution, > >A. Andersson and J. P. H. Sladen, CERN (EUROTeV Report 2008-015) > >[phase detector with 8x AD835 analog multipliers]. > > > >ANDERSSON, A. and SLADEN, J. P. H.: "First tests of a precision beam > >phase measurement system in CTF3" (Proc. PAC07). > > > >"PRECISION BEAM TIMING MEASUREMENT SYSTEM FOR CLIC SYNCHRONIZATION," > >A. Andersson, J. P. H. Sladen, CERN (Proceedings of EPAC 2006). > > > >Best regards, > > > >Charles > > ___ > 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Bruce wrote: You mean DMTD = dual mixer time differencenotDDMTD = Digital dual mixer timer difference.The latter uses a pair of synchronisers / shift registers instead of a pair of mixers. I don't see how your comment is relevant to my post -- I did not mention either DMTDs or DDMTDs. I only noted that the AD835 is noisier than a diode mixer, although not as noisy as many analog multipliers -- and that some noise improvement has been demonstrated by using parallel multipliers. Charles On Wednesday, 6 January 2016 12:03 PM, Charles Steinmetz wrote: Poul-Henning wrote: >My little HP5065 project is continually running into the jitter of >my HP5370B counter which is annoying me, so I'm looking int DMTD. > >Everybody seems to be using traditional diode-mixers for DMTD, >and to be honest I fail to see the attraction. > >Why wouldn't a analog multiplier like AD835 be better idea ? > >What am I overlooking ? You could have mentioned any of dozens of popular analog multipliers, and the answer would have been, "because they are way too noisy." The AD835 is also substantially noisier than diode mixers, but it at least begins to bridge the gap. The folks at CERN have been improving phase detector S/N by averaging the output of several AD835s for the TPMON project, with promising results. There is a preliminary report in "EUROTeV Report 2006-005-1." See also: RF-based electron beam timing measurement with sub-10fs resolution, A. Andersson and J. P. H. Sladen, CERN (EUROTeV Report 2008-015) [phase detector with 8x AD835 analog multipliers]. ANDERSSON, A. and SLADEN, J. P. H.: "First tests of a precision beam phase measurement system in CTF3" (Proc. PAC07). "PRECISION BEAM TIMING MEASUREMENT SYSTEM FOR CLIC SYNCHRONIZATION," A. Andersson, J. P. H. Sladen, CERN (Proceedings of EPAC 2006). Best regards, Charles ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Hi Ok, so what needs to be done with the output of the mixer (no matter how you do it)? Assume you start from 10 MHz and head down to 10 Hz. Assume you are mad at your 5370 and want significantly better performance. Where does that get you? The 5370 already is in the ~ 20 ps range. A lot depends on your definitions and how good your sample is running. Let’s call that 2x10^-11 at tau = 1 second. You could indeed call it a couple of other things as well. Simply moving up a decade with a whole bunch of gear and it’s limitations seems like a waste. To me you want to go for 1 to 2x10^-13 as your target. It is an achievable target and there are a number of papers that validate it as a reasonable DMTD target. You get a 1x10^6 “amplification due to your down mix from 10 MHz to 10 Hz. You then need another 1x10^7 to get you to your target. All errors from everything included, you need to work out the location of the zero crossings to within 100 ns. The practical examples of doing it include some fairly tight lowpass filtering as well as high pass filtering ahead of the detection process. I have never seen it done without this filtering as part of the setup. There is just to much noise at the detector otherwise. Most systems have something like a 15 Hz lowpass and a 5 Hz high pass for a 10 Hz note. With fairly good diode ring phase detectors and a less than perfect (not 25 stage Collins style) analog limiter, you can indeed get to the target. Doing it digitally assumes you have a pretty good clock and sampler. If you look at it as a 3V p-p triangle waveform at 10 Hz, you have a 60V / second slew rate. (a 1 V p-p sine wave is pretty close to the same number). You need to filter that at 15 Hz and then resolve it to about 6 uV at the zero crossing. You can either keep a high sample rate and make your filter a major nightmare or you can decimate ahead of the filter and turn the resolver into a headache. Either way, there is some work to be done. A couple of op-amp packages is about all it takes to do the limiter with the analog approach …. Bob > On Jan 5, 2016, at 6:58 PM, Magnus Danielson > wrote: > > Hi Poul-Henning, > > On 01/06/2016 12:28 AM, Poul-Henning Kamp wrote: >> >> In message <568c46b9.4020...@rubidium.dyndns.org>, Magnus Danielson writes: >> >>> The white noise will be particularly annoying as it then converts to >>> jitter through the slew-rate limitation as you go into the >>> trigger-circuit. >> >> Digitize the LPF output and do a curve-fit to find the zero-crossings ? >> > > That would work. You could least-square fit it with very cheap processing. > The LPF would mainly need to reject the sum frequencies to act as > anti-aliasing filter, and the noise would be filtered out by the least-square > processing. > > Estimating the phase and slew-rate, and then use those to calculate the > actual through-zero phase would not be too hard. As a consequence you get a > slew-rate monitor, which act as an observation of signal level. > > Cheers, > Magnus > ___ > 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Poul-Henning wrote: My little HP5065 project is continually running into the jitter of my HP5370B counter which is annoying me, so I'm looking int DMTD. Everybody seems to be using traditional diode-mixers for DMTD, and to be honest I fail to see the attraction. Why wouldn't a analog multiplier like AD835 be better idea ? What am I overlooking ? You could have mentioned any of dozens of popular analog multipliers, and the answer would have been, "because they are way too noisy." The AD835 is also substantially noisier than diode mixers, but it at least begins to bridge the gap. The folks at CERN have been improving phase detector S/N by averaging the output of several AD835s for the TPMON project, with promising results. There is a preliminary report in "EUROTeV Report 2006-005-1." See also: RF-based electron beam timing measurement with sub-10fs resolution, A. Andersson and J. P. H. Sladen, CERN (EUROTeV Report 2008-015) [phase detector with 8x AD835 analog multipliers]. ANDERSSON, A. and SLADEN, J. P. H.: "First tests of a precision beam phase measurement system in CTF3" (Proc. PAC07). "PRECISION BEAM TIMING MEASUREMENT SYSTEM FOR CLIC SYNCHRONIZATION," A. Andersson, J. P. H. Sladen, CERN (Proceedings of EPAC 2006). Best regards, Charles ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Hi Poul-Henning, On 01/06/2016 12:28 AM, Poul-Henning Kamp wrote: In message <568c46b9.4020...@rubidium.dyndns.org>, Magnus Danielson writes: The white noise will be particularly annoying as it then converts to jitter through the slew-rate limitation as you go into the trigger-circuit. Digitize the LPF output and do a curve-fit to find the zero-crossings ? That would work. You could least-square fit it with very cheap processing. The LPF would mainly need to reject the sum frequencies to act as anti-aliasing filter, and the noise would be filtered out by the least-square processing. Estimating the phase and slew-rate, and then use those to calculate the actual through-zero phase would not be too hard. As a consequence you get a slew-rate monitor, which act as an observation of signal level. Cheers, Magnus ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
In message <568c46b9.4020...@rubidium.dyndns.org>, Magnus Danielson writes: >The white noise will be particularly annoying as it then converts to >jitter through the slew-rate limitation as you go into the >trigger-circuit. Digitize the LPF output and do a curve-fit to find the zero-crossings ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
You mean DMTD = dual mixer time differencenotDDMTD = Digital dual mixer timer difference.The latter uses a pair of synchronisers / shift registers instead of a pair of mixers. Bruce On Wednesday, 6 January 2016 12:03 PM, Charles Steinmetz wrote: Poul-Henning wrote: >My little HP5065 project is continually running into the jitter of >my HP5370B counter which is annoying me, so I'm looking int DMTD. > >Everybody seems to be using traditional diode-mixers for DMTD, >and to be honest I fail to see the attraction. > >Why wouldn't a analog multiplier like AD835 be better idea ? > >What am I overlooking ? You could have mentioned any of dozens of popular analog multipliers, and the answer would have been, "because they are way too noisy." The AD835 is also substantially noisier than diode mixers, but it at least begins to bridge the gap. The folks at CERN have been improving phase detector S/N by averaging the output of several AD835s for the TPMON project, with promising results. There is a preliminary report in "EUROTeV Report 2006-005-1." See also: RF-based electron beam timing measurement with sub-10fs resolution, A. Andersson and J. P. H. Sladen, CERN (EUROTeV Report 2008-015) [phase detector with 8x AD835 analog multipliers]. ANDERSSON, A. and SLADEN, J. P. H.: "First tests of a precision beam phase measurement system in CTF3" (Proc. PAC07). "PRECISION BEAM TIMING MEASUREMENT SYSTEM FOR CLIC SYNCHRONIZATION," A. Andersson, J. P. H. Sladen, CERN (Proceedings of EPAC 2006). Best regards, Charles ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
On Tuesday, January 05, 2016 09:37:00 PM Poul-Henning Kamp wrote: > > > In message <553575724.582265.1452024437677.javamail.ya...@mail.yahoo.com>, Bruce Griffiths writes: > >The noise of such Gilbert cell based analog multipliers far exceeds that of > >the traditional mixer. > Yes, but does that really matter in this case ? > > The interesting output will be coming out of a LPF so > most of the noise will die there?/ Yes I believe it does as the mixer multiplier noise sets a lower limit to the beat frequency jitter. If only the noise from the 2 mixers were correlated then the jitter contribution from this would largely cancel out as does the noisee contribution of the offset oscillator. Bruce ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Poul-Henning, On 01/05/2016 10:37 PM, Poul-Henning Kamp wrote: In message <553575724.582265.1452024437677.javamail.ya...@mail.yahoo.com>, Bruce Griffiths writes: The noise of such Gilbert cell based analog multipliers far exceeds that of the traditional mixer. Yes, but does that really matter in this case ? The interesting output will be coming out of a LPF so most of the noise will die there? You still raise the noise-level which is in the pass-band of those filters. This will be true both for white noise and flicker noise. The white noise will be particularly annoying as it then converts to jitter through the slew-rate limitation as you go into the trigger-circuit. To reduce this effect, we amplify up the signal in steps, with higher and higher bandwidth to balance noise contribution with slew-rate incrementation. Using noisy mixers rather than quieter mixers makes this more worthwhile. The diode mixers needed does not have to be very rare, just look at the 2NA based mixer out of NIST, actually being a Harris chip with four transistors and a pair of off the shelf transformers. Yes, I've played with this, ran into the issues. Tried to build a DTMD, but didn't manage to handle some problems before it got side-tracked. As always, choosing the trigg-point to have the highest slew-rate have always been key to reducing timing jitter.k Turns out that most counters isn't optimized for this property. Cheers, Magnus ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Mini-circuits has packaged phase detectors plug-in, surface, and with connectors for $20 TO $70. Diode bridges with transformers. They also have cheap wideband amps. Bet a simple DDMTD could be built with these? I know...I wish I did have the time at present. Happy New Year! Don Magnus Danielson > With some sine-to-square conversion as signal conditioning, not too hard > these days, this could be a relatively straight forward approach. > CERN already have digital clocks, so the DDMTD approach fits them well. > > For normal mixers you want to signal condition the signal prior to the > mixers, and then signal-condition the beat notes too. > > For DDMTD you do the same, but you do the post mister conditioning in > the digital domain. > > I have always assumed that signal-to-noise have been the main difference > between the Gilbert cell multiplies vs. diode mixers. > > Cheer1s, > Magnus > > On 01/05/2016 09:19 PM, Bruce Griffiths wrote: >> You could also consider a DDMTD as useed in CERN's White rabbit >> project.Apart from the sine to logic level conversion its all digital. With >> care in the design the jitter should be sub picosecond. >> Bruce >> >> >> On Wednesday, 6 January 2016 9:01 AM, Poul-Henning Kamp >> wrote: >> >> >> My little HP5065 project is continually running into the jitter of >> my HP5370B counter which is annoying me, so I'm looking int DMTD. >> >> Everybody seems to be using traditional diode-mixers for DMTD, >> and to be honest I fail to see the attraction. >> >> Why wouldn't a analog multiplier like AD835 be better idea ? >> >> What am I overlooking ? >> > ___ > 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. > > -- Felix qui potuit rerum cognoscere causas. Lucky is he who has been able to understand the causes of things. Virgil --- "Noli sinere nothos te opprimere" Dr. Don Latham, AJ7LL Six Mile Systems LLC, 17850 Six Mile Road Huson, MT, 59846 mailing address: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 CEL 406-241-5093 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
With some sine-to-square conversion as signal conditioning, not too hard these days, this could be a relatively straight forward approach. CERN already have digital clocks, so the DDMTD approach fits them well. For normal mixers you want to signal condition the signal prior to the mixers, and then signal-condition the beat notes too. For DDMTD you do the same, but you do the post mister conditioning in the digital domain. I have always assumed that signal-to-noise have been the main difference between the Gilbert cell multiplies vs. diode mixers. Cheer1s, Magnus On 01/05/2016 09:19 PM, Bruce Griffiths wrote: You could also consider a DDMTD as useed in CERN's White rabbit project.Apart from the sine to logic level conversion its all digital. With care in the design the jitter should be sub picosecond. Bruce On Wednesday, 6 January 2016 9:01 AM, Poul-Henning Kamp wrote: My little HP5065 project is continually running into the jitter of my HP5370B counter which is annoying me, so I'm looking int DMTD. Everybody seems to be using traditional diode-mixers for DMTD, and to be honest I fail to see the attraction. Why wouldn't a analog multiplier like AD835 be better idea ? What am I overlooking ? ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Hi Bruce, Thanks a LOT for your response to Poul's query! I've been searching for DMTD info for a few some time now, and I haven't come up with a lot. Searching for "CERN White Rabbit" got me more in a few minutes than I've found in months. Like Poul, I've become interested in building a DMTD to overcome the limitations of my 5370A, but I haven't had time to actually do anything about it yet. Bob From: Bruce Griffiths To: Discussion of precise time and frequency measurement Sent: Tuesday, January 5, 2016 2:19 PM Subject: Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ? You could also consider a DDMTD as useed in CERN's White rabbit project.Apart from the sine to logic level conversion its all digital. With care in the design the jitter should be sub picosecond. Bruce On Wednesday, 6 January 2016 9:01 AM, Poul-Henning Kamp wrote: My little HP5065 project is continually running into the jitter of my HP5370B counter which is annoying me, so I'm looking int DMTD. Everybody seems to be using traditional diode-mixers for DMTD, and to be honest I fail to see the attraction. Why wouldn't a analog multiplier like AD835 be better idea ? What am I overlooking ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
In message <553575724.582265.1452024437677.javamail.ya...@mail.yahoo.com>, Bruce Griffiths writes: >The noise of such Gilbert cell based analog multipliers far exceeds that of >the traditional mixer. Yes, but does that really matter in this case ? The interesting output will be coming out of a LPF so most of the noise will die there? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
In message , paul swed writes: >I think the analog multipliers are complicated in pins and support >circuitry especially if single power supply. The AD835 is 8-pins and as easy as they come I think. Not needing isolation amps seems like a plus to me. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
You could also consider a DDMTD as useed in CERN's White rabbit project.Apart from the sine to logic level conversion its all digital. With care in the design the jitter should be sub picosecond. Bruce On Wednesday, 6 January 2016 9:01 AM, Poul-Henning Kamp wrote: My little HP5065 project is continually running into the jitter of my HP5370B counter which is annoying me, so I'm looking int DMTD. Everybody seems to be using traditional diode-mixers for DMTD, and to be honest I fail to see the attraction. Why wouldn't a analog multiplier like AD835 be better idea ? What am I overlooking ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
Poul-Henning, I have some guesses but I look forward to others. I think the analog multipliers are complicated in pins and support circuitry especially if single power supply. I used lower frequency Analog Devices units in early experimentation on the wwvb d-psk-r. Granted they worked. They were also pricey. But thats relative. They can deliver gain as compared to a mixer and thats a plus. Regards Paul WB8TSL On Tue, Jan 5, 2016 at 2:56 PM, Poul-Henning Kamp wrote: > My little HP5065 project is continually running into the jitter of > my HP5370B counter which is annoying me, so I'm looking int DMTD. > > Everybody seems to be using traditional diode-mixers for DMTD, > and to be honest I fail to see the attraction. > > Why wouldn't a analog multiplier like AD835 be better idea ? > > What am I overlooking ? > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > ___ > 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.
Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?
The noise of such Gilbert cell based analog multipliers far exceeds that of the traditional mixer. Bruce On Wednesday, 6 January 2016 9:01 AM, Poul-Henning Kamp wrote: My little HP5065 project is continually running into the jitter of my HP5370B counter which is annoying me, so I'm looking int DMTD. Everybody seems to be using traditional diode-mixers for DMTD, and to be honest I fail to see the attraction. Why wouldn't a analog multiplier like AD835 be better idea ? What am I overlooking ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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.
