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AD9951 ROM length

Question asked by Technophobe on Sep 24, 2012
Latest reply on Oct 18, 2012 by KennyG

Hi Guys

 

Does anyone have any idea how long the sine lookup table is in the AD9951 and AD9834? Maybe I missed it in the datasheets, but I don't think it's in there. I have a noise problem that I can't get to the bottom of using the AD9834 @ 66.666MHz clock to generate spot frequencies from 30kHz - 1MHz.

 

Also:

 

For best sine waveform reconstuction, am I better filtering at Nyquist or just above 1MHz? (I realise I will not attenuate a lot of the spurs at Nyquist, but I was thinking of the interpolating gradient between 'steps').

 

 

Cheers

 

Pat

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