# differential non-linearity (DNL)

Differential nonlinearity is a characteristic value of A/D converters that describes the maximum errors of

the quantization stages. Ideally, all quantization stages have the same time intervals. The deviation of the quantization stages from the ideal is referred to as differential nonlinearity (DNL). The DNL value indicates the positive or negative deviation from the ideal width for each individual quantization stage, in terms of the number of least significant bits

(LSB). For error-free quantization stages, the stage transition thus corresponds to 1 LSB, resulting in a staircase-like increase in the threshold voltage, with each stage having the same stage width.

The differential nonlinearity corresponds to the step deviation from the ideal and results in the analog input signal being sampled slightly earlier or later than after 1 LSB. The sum of the DNL values corresponds to the integral nonlinearity. The differential nonlinearity DNL (i) indicates for each stage i the positive or negative deviation from the ideal width in units of LSB (Least Significant Bit); 1 LSB corresponds to the ideal width. By summing up the DNL (i) over all stages up to stage k, the integral nonlinearity INL (k) is obtained.