Gennerally, in the theory , the SNR:
SNR=6.02N+1.76+20log(k) (I)
K: the oversampling rate(OSR)=(ks/2)/Kin,
But actually , the measure do not meet the value.
such as a 14bit ADC (Nyquist sample):
in theory the SNR(Therory)=6.02*14+1.76
but the measure SNR(measure)<SNR(Theory)
Ex. a Nbit ADC input signal Vpsin(ωt),the reference is Vref+, Vref-,
RMS(the maxim input signal)=Vref+-LSB-Vref-
RMS(the noise power)=LSB/(√12)
LSB=(Vref+-Vref-)/(2....2)
--------
N
the DR=20log(the maxim range signal power)/(the noise power))
=6.02N
in theory , DR=6.02N