AD9837 issue...


I would like to ask a question about the following issues.

- System

  ; AD9837 evk(Mclk 16Mhz) + control board + AD9837 SDZ(PC Tool)

  ; PC Tool setting  -> Freqreg = 3Mhz, Phase = 0,. Sleep option = Full Power UP, Iout Output = Sinusoidal, Sign Bit OutPut = Phase Accumulatro

- Probleme

  ; I want a 3Mhz output, and a fine change in 100hz increments.

    However, if the frequency is set to 3Mhz, frequency and duty shake occurs.( Freq = 2.6Mhz ~ 3.2Mz shake. dyty = 30% ~ 45% shake)

   Frequency dupe shake is present at most other frequency settings... ex> 2.1Mhz, 4,1Mhz, 9Mhz, 10Mhz,,,,,,


- Q&A

  (1) Is the AD9837 able to accurately output only the frequency that is correctly divided?

    Ex> 4Mhz, 2Mhz, 3.2Mhz ... ...

  (2) If (1) is correct, is there a solution for other frequencies?

  thank you all the time....