#### fanisani

##### Newbie level 6

what is the difference between harmonic and spur?

in ADC because of non-linearity, input driving and s\h circuit

at output we see that harmonics of input signal appear at ADC

spectrum.

The ideal ADC has the quantization noise as a white noise (in certain condition, and

i think it appear because of non-linearity of transfer function of ADC)but if the input

is a pure single tone it has no spur in the spectrum . so i think about INL and DNL

error and how can they cause spur in the spectrum in low frequency.

but in calculation of SFDR we must think of worst spur.references say that spur can

be harmonic of input signal or may be distortion.

at level of signal near full scale worst spur be a harmonic , but at low level signal

may be not a An ideal N-bit ADC, sampling at a rate fs, produces quantization

noise having an rms value of q/(sqrt 12) measured in the Nyquist bandwidth dc to

fs/2.

An actual ADC will produce noise in excess of the theoretical

quantization noise, as well as distortion products caused by a non-linear transfer

function. but i think quantization noise is also because of non-linearity.????????????