Hi Ron,
that is the value for the 10MHz output!
Perhaps we can have a more exact measurement.
Best regards,
Detlev
External reference from ICS512 (PLL CLOCK MULTIPLIER)
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Detlev, I will have a go, but I doubt my simple equipment is capable of nulling out the carrier enough -- even with a notch.
If I can manage it I will let you know. 73.s de Ron.
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Hi Detlev,
I could not do any sensible measurements at 40MHz because my hybrid couplers are not good enough at that frequency.
So I used a different approach and made a measurement at 50MHz.
The picture shows the 50MHz (+8dBm) carrier passing through a 50.125MHz crystal filter, the filter attenuates the 50MHz signal by almost 50dB.
What is left is the true RMS level of noise passing through the filter, The cursor shows the analyser noise floor at -122.5 dBm.
The Leo Bodnar device noise measured at 50.100MHz is -107dBm.
As to how that will relate to 40MHz I will leave to others. This is my final opinion on the subject.
Regards everybody and stay safe.
Ron.
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Not a very scientific test, but here you see the 10kHz offset at -70.16dB
Measured at 40MHz on H.P. analyser.
IS NOT EXACT 70 dB!!! add 10log RBW value to readout. in any case for measurements of PHASE NOISE by spectrum analizer, open span greate 5 times then desired offset value.
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in any case issue with ISC5XX series i was test in 2014. for simple explane final PHASE NOISE value will lower than -40dBc/Hz at 10 kHz offset. from datasheet page of IDT_511 device: One Sigma Clock Period Jitter tjs 25 ps. (This parameter of ICS512 is 70 ps!!!) see datasheet pages of devices
https://rf-tools.com/jitter/- calculator link
LTC6950 is better solution, is 1.4GHz Low Phase Noise,Low Jitter PLL with Clock Distribution device
https://www.analog.com/media/en/technical-documentation/data-sheets/6950f.pdf
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Hello all, I have access to an R&S FSUP and can measure PN . I have attached a few examples in the pdf, You can pretty much infer results for other frequencies for the Leo Bodnar results from the 10 MHz plot included. If you want to see 40MHz and 25MHz specifically I should be able to measure them on Friday this week.
Regards
Conrad PA5Y
