Lesson 6 – Executing the DAC Linearity Test
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6-1 DAC Linearity Measurements
DAC linearity is measured by applying a quasi-static digital ramp
signal which covers the full code range.
DAC linearity measurements include:
DAC Static Parameters (Linearity)
DAC Differential Non-Linearity
Differential non-linearity (DNL) measures the deviation of the
actual step size from the ideal step size of 1 LSB. The DNL is
expressed in fractions of 1 LSB.
The DNL of an ideal DAC is zero.
Definition of DAC DNL
As the DNL is measured from step to step, the number of values
returned by the DNL calculation is 2
n
–1 where n is the resolution
of the DAC (the number of bits). A DAC DNL test checks the
maximum of these values against a given limit to determine the
pass/fail result.
•Differential Non-Linearity (DNL)
•Integral Non-Linearity (INL)
•Gain Error
•Offset Error
•Gain Mismatch