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AD9858 DFTW calculation problem

Question asked by Yake on Jun 13, 2014
Latest reply on Jun 16, 2014 by KennyG

Hello, on the 18th page of AD9858 datasheet, there is a formula to calculate DFTW, which is

t=abs(fF-fs)*2^34/sysclk^2*DFRRW/DFTW

but when i use the DFTW result got from this equation (t, abs(fF-fs) and DFRRW are known) to control the DDS, i always get only half the abs(fF-fs). Should this equation be

t=abs(fF-fs)*2^35/sysclk^2*DFRRW/DFTW

Thanks very much!

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