I have a further question which is related to this matter.
I am using ADIsimCLK v1.70 to verify my proposed set-up for the AD9528.
I end up having a frequency of 1.28906GHz at the output of M1 (VCO freq 3.86719GHz, M1 = 3 (some small rounding errors)) which results in the error "Max M1 out freq is 1.25GHz". I cannot find an explicit reference to this limitation in the datasheet.
I plan to divide this down using the 8-bit channel dividers in the clock distribution part to be less than 1GHz at each output.
Is this an error in ADIsimCLK?
Should the limitation be placed after the channel divider (as per your reply)?
Is there a maximum frequency that the 8-bit channel dividers can be run at?
I have just noticed that this is actually explained here (Query in AD9371 Evaluation Board VCXO selection doc ).
I assume this is just a bug in ADIsimCLK. Can you please confirm?
Datasheet says max frequency as 1.25 GHz, and hence it is limited in SimCLk as well.
Moving to clock and timing subspace for more comments.