Progrock2: Output impedance versus best phase noise performance
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Hi -
I am perplexed by a comment in the Progrock2 manual:
"For best phase noise performance, as well as least crosstalk between Si5351A outputs, it is recommended to use loads of at least 1 K-ohm."
The outputs of the Si5351 are for a 50-ohm impedance, but the preceding suggests it should be 1 K-ohm. What does this mean? Should the Si5351 be connected to a voltage divider so that the Si5351 "sees" 1 K-ohm while the next stage "sees" 50-ohms? That would, of course, lower that peak-to-peak voltage substantially. I am trying to imagine how that could be correct.
The Si5351 datasheet did not resolve my confusion.
Do you have any suggestions or clarifications?
-Bob
WA2I
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