Integral NonlinearityIntegral nonlinearity refers to the deviation of each individual code from a line drawn from zero through fullscale. The point used as zero occurs one-half LSB before the first code transition. The full-scale point isdefined as level one-half LSB beyond the last code transition. The deviation is measured from the centerof each particular code to the true straight line between these two points.Differential NonlinearityAn ideal ADC exhibits code transitions that are exactly 1 LSB apart. DNL is the deviation from this idealvalue. A differential nonlinearity error of less than ±1 LSB ensures no missing codes.Zero OffsetThe major carry transition should occur when the analog input is at zero volts. Zero error is defined as thedeviation of the actual transition from that point.Gain ErrorThe first code transition should occur at an analog value one-half LSB above negative full scale. The lasttransition should occur at an analog value one and one-half LSB below the nominal full scale. Gain error isthe deviation of the actual difference between first and last code transitions and the ideal differencebetween first and last code transitions.Signal-to-Noise Ratio + Distortion (SINAD)SINAD is the ratio of the rms value of the measured input signal to the rms sum of all other spectralcomponents below the Nyquist frequency, including harmonics but excluding dc. The value for SINAD isexpressed in decibel |
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