Lesson 6 – Executing the DAC Linearity Test
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Calculation of DAC INL
Like for the DNL measurement, the software provides three
calculation methods: End point, zero-point, and minimum rms.
The DeviceLSB is calculated as for the corresponding DNL
measurement. For more information about the calculation of the
DeviceLSB and of the reference voltage V
ref
, see the Appendix
“Definition of DAC and ADC Characteristics” on page 567.
DAC Offset Error
The offset error is calculated from the output voltage at code zero.
The offset error is also called linear displacement.
The end point method is used to calculate the DeviceLSB.
Definition and Calculation of Offset Error
Integral Non-Linearity can be calculated using the end-point method, zero-
point method, or minimum root mean square method. All three methods use
the same formula. Only the definition of the DeviceLSB and Vref varies from
method to method.
where i = 0, 1, 2, ... 2
n
–1
The DeviceLSB is calculated as for the DNL measurement.
Offset Error =
DeviceLSB
V(0)
Digital Input code
Discrete Analog
Output Voltage
V(0)
Ideal transfer curve