I think they do not have direct relationship. If bit (i) DNL is -1.5dB, bit (i+1) DNL is 1dB, bit (i+2) DNL is 0.5dB, then the total INL induced is zero and there is no missing code. Code (i+1), (i+2) is still there.
The DNL it is the normalized deviation of the difference between two consecutive code transition levels, with respect to the ideal value, VLSB:
DNL(i)=(Vt[i+1]-Vt-VLSB)/VLSB=(Vt[i+1]-Vt)/VLSB-1
where Vt is the input voltage where the transition from code i-1 to i occurs.
Thus, when DNL=-1, we have Vt[i+1]=Vt, which means that code i does not exist -> missing code.
DNL < -1LSB does not mean that a code is missing. But it implies that the converter is not monotonic. Which may be a serious matter in closed loop applications such as regulation.
Hi,
In my view the definition is correct....although it is not the actual definition...but the definition implies this....you can go thru the folloing post ....a very good book...and hopefully convince on the matter....