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AD9910; Question about some spurs nearby fout.

Question asked by JongWon on Feb 18, 2013
Latest reply on Feb 19, 2013 by LouijieC

Hello.

 

I'm using AD9910.

 

I got some problem about AD9910.

 

Please give me some advice.

 

I'm sorry about my poor English.

 

my system clk is 760MHz.

 

I want to lock to 210MHz.

 

After calculation by CPU, FTW is 0x46BCA200.

 

If I using that value, some spurs exist nearby 210MHz. difference : 60hz.

 

difference between spurs and fout is changing related to fout.

 

Spurs amplitude is so high.

 

Is it normal operation?

 

If not, please let me know why is that.

 

(about AD9910 eval board program, 210MHz's FTW is 0x46BCA1AF, and that value has no spurs.

 

But some other freq.s has spurs still.)

 

Thank you for your reply in advance.

 

Sincerely.

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