hi,
i calculated my THD by keeping a fourier component at output.
Conditions : FIn=10.1318MHz,FS=125Mhz,Cycles=83,Samples=1024.
I have plotted 512 hormonics by giving normhorm=83,hormonics=512,Fund=122.07Khz and found THD=57db.
In that 512 hormonics i taken out  5 hormonics (83,83*2,83*3,83*4,83*5)and calculated THD=63.15db.
now my doubt is whether these 512 hormonics includes THD+transient noise+thermal noise,or its only THD(hormonic components).
If it is THD+noise,is it  equal to SNDR of DAC.
SNDR=S/N+THD.
Most of papers are specifying only 1st ,2nd 3rd,4th,and 5th hormonic output as THD but here we r including all frequencies till Fs/2.That the reason i got this doubt

Regards
venkats