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ADF4350 Phase sync with feedback from output divider

Question asked by Stuart on Aug 19, 2013
Latest reply on Sep 13, 2013 by icollins

I want to be able to use the phase register setting in an ADF4350.  To be to get consistent phase settings, I need to take the N-divider input from the Output Divider.  This works okay so long as the Output Divider is 2 or 1.   When the Output Divider is >2, then the synthesizer becomes unlocked.

 

Monitoring the N-divider output from the MUX shows there is no output from the N-divider (see note below) when the Output Divider >2 and the N-divider is from the Output Divider.

 

Is there something wrong with being able to use the feedback from the output divider in some conditions?

 

 

 

Note:

To get the N-divider output from the MUX output function correctly, the registers must first be written in descending order with R2 MUX set to tri-state. Then re-write register 2 with MUX = N-divider output. 

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