Definitions for "Offset Error"
Keywords:  zero, ideal, deviation, unipolar, lsb
The deviation of the analog output from the ideal of "0".
The measurement of offset error in bipolar converters is similar to that of offset error in unipolar converters. However, the error measured at zero-scale is at the midpoint of the bipolar transfer functions. (See Offset Error (Unipolar).)
Offset error, often called 'zero-scale' error, indicates how well the actual transfer function matches the ideal transfer function at a single point. For an ideal data converter, the first transition occurs at 0.5LSB above zero. For an ADC, the zero-scale voltage is applied to the analog input and is increased until the first transition occurs. For a DAC, offset error is the analog output response to an input code of all zeros.