I have started to build the next reclocker using EL52, EL11, blue LEDs.
Next Upgrade will be E1651 comparator, only userfriendly chip I could find.
For the LVPECL it is better to make a layout for a printed circuit bord, I have no motivation to hand wire that tiny comparator package. Someday...
Next Upgrade will be E1651 comparator, only userfriendly chip I could find.
For the LVPECL it is better to make a layout for a printed circuit bord, I have no motivation to hand wire that tiny comparator package. Someday...
I can only find NECL comparators at On Semi, right ?
Quick expensive ......
I guess I'll have to stick to AD or MAX for PECL.
Patrick
Quick expensive ......
I guess I'll have to stick to AD or MAX for PECL.
Patrick
Why make it more complicated than necessary ?
I am find with AD or MAX.
😉
Also have a look at this :
http://www.diyaudio.com/forums/digital-line-level/70107-da-capo-issue-john-w-15.html#post2070821
Patrick
I am find with AD or MAX.
😉
Also have a look at this :
http://www.diyaudio.com/forums/digital-line-level/70107-da-capo-issue-john-w-15.html#post2070821
Patrick
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I would not take it for granted, as we know there are different generations of ECL, what did he use ? SE or diff. ? Translation to the DAC ?
Also NECL logic levels are referenced to ground and not to a regulated voltage. Concerning the isolation, I still think about injecting the divided clock into the DAC to avoid jitter feed through the flipflop.
The E1651 seems to work PECL also.
Also NECL logic levels are referenced to ground and not to a regulated voltage. Concerning the isolation, I still think about injecting the divided clock into the DAC to avoid jitter feed through the flipflop.
The E1651 seems to work PECL also.
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Hi,
maybe this article (I am sure that You already known to You)
http://www.audiocraftersguild.com/AandE/cd-jitter.pdf
could help about transistor driver bus powered with -5.2V
just info
btw great stuff guys You did
thanks
maybe this article (I am sure that You already known to You)
http://www.audiocraftersguild.com/AandE/cd-jitter.pdf
could help about transistor driver bus powered with -5.2V
just info
btw great stuff guys You did
thanks
Welcome back in snowland ! 
Not much happened, I have received EL52, EL11 and blue LEDs, still waiting for smd adapters.
LEDs have parasitic capacitance of 120 pF or so, I measured with C meter.
If you drive an LED with a source impedance Zp = 7 ohm for ECL output and add a load resistor Zs = 300 ohm > Zp on the other side of the LED, there will be overshoot on LED/Zs, undershoot on LED/Zp and a slow rise and fall across the LED.
I did simulation with parallel cap and it showed these effects.
Also measurement on real translator using bypass cap.
So I would not expect any bandwith problem.
Even more if you add a cap, you will gain voltage swing.
Upper trace ECL output, lower trace DAC input with 100n cap.
But what if one does what I suggested :
Terminate ECL with say 100R before LED. Load LED out pin (cathode in case of PECL) to -5V with a J508 or equivalent. Then there should be no current fluctuation across the LED, and thus no charging discharging of capacitance, hence no RC effects.
At least this is the theory.
Patrick
Terminate ECL with say 100R before LED. Load LED out pin (cathode in case of PECL) to -5V with a J508 or equivalent. Then there should be no current fluctuation across the LED, and thus no charging discharging of capacitance, hence no RC effects.
At least this is the theory.
Patrick
A current regulator diode is basically a FET.
Do you have information about the bandwith ?
Normally FETs are somehow limited.
I still have a headache from the LED...
Do you have information about the bandwith ?
Normally FETs are somehow limited.
I still have a headache from the LED...
No, except that the capacitance is quoted at 2.2p at 1MHz.
But I guess we could use an RF-JFET as current diode. There seems to be many to choose from, e.g. BF861.
Might need some degeneration to get the right current.
Patrick
But I guess we could use an RF-JFET as current diode. There seems to be many to choose from, e.g. BF861.
Might need some degeneration to get the right current.
Patrick
I will stick to LED + voltage divider V+ to gnd on the DAC input.
That is proved to work for me and allows to adjust for symmetrical swing around the DAC switching point.
The CRDs have high tolerances which together with the LED tolerances shift the voltage swing away from the switching point. You would have to adjust with the termination resistor or select LEDs or CRDs.
That is proved to work for me and allows to adjust for symmetrical swing around the DAC switching point.
The CRDs have high tolerances which together with the LED tolerances shift the voltage swing away from the switching point. You would have to adjust with the termination resistor or select LEDs or CRDs.
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I'll have to do some experiment some time, but not now, unfortunately.
Too many other things with higher priorities.
🙁
Patrick
Too many other things with higher priorities.
🙁
Patrick
Yes, at some point practical evaluations start to be very helpful.
Modern LEDs are very sensitive, if you touch one end and tip any earth or ground, it will light up.
Modern LEDs are very sensitive, if you touch one end and tip any earth or ground, it will light up.
Bernhard,
It's been a while.
2 long weekends means some progress on PCB layout and circuit details (and not just the diff clock).
A question came to mind. Do you have a photo of the sinusoidal output of your balanced Colpitts ?
I wonder what the amplitude would be, and whether they exceed 4V single ended.
The MAX9601 is specified at 5V differential maximum, and the ADCMP567 at 7V.
But the latter is really very fiddly to solder.
🙁
Any hints would be a great help.
Many thanks in advance.
Patrick
It's been a while.
2 long weekends means some progress on PCB layout and circuit details (and not just the diff clock).
A question came to mind. Do you have a photo of the sinusoidal output of your balanced Colpitts ?
I wonder what the amplitude would be, and whether they exceed 4V single ended.
The MAX9601 is specified at 5V differential maximum, and the ADCMP567 at 7V.
But the latter is really very fiddly to solder.
🙁
Any hints would be a great help.
Many thanks in advance.
Patrick
No, my HF sampling plugin does not allow very good resolution at > 10 MHz.
But I checked with the spectrum analyzer and it is clean.
The amplitude is 600 mV pp per output which means 600 mV diff.
This is also determined by the 1k resistors on the output.
Anyway with 5V supply it will get hard to exceed 4V without clipping.
I did not continue to work on the LED reclocker, was fiddling with my speakers all the time...
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