We have three channels, REFin are given by FPGA(another borad), 20MHz.
ADF4350 are configured with the same program, PFD has been set to 1MHz,and muxout has been set to R div,
but one of the outputs is 1MHz, another two are 2MHz
What do you mean by 'three channels'? Do you have three separate ADF4350 chips?
If they are all connected the same, and programmed with the same register settings, there is no reason that the Muxout frequencies would be different.
What is your PFD frequency? I saw your other post (http://ez.analog.com/message/112697) - you say your PFD frequency is 2 MHz, but the register settings (R = 10 and Ref/2 enabled) give a 1 MHz PFD frequency.
When Muxout is set to R divider output, the output will be equal to the PFD frequency.
Thanks to reply !
We have modified the PFD frequency to be 1MHz, and the program of three channels are the same, but the outputs of Muxout are different.
Yes, we have three separate ADF4350 chips, and their register are set by the FPGA which is on the other borad. We use logic analyzers to observe CLK, DATA and LE, all of them are normal.
Now we consider that the poor connection in these two boards may be the cause of this problem.
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