Dc Testing-Histogram; Ac Testing-Histogram - Analog Devices EVAL-AD7625FMCZ User Manual

EVAL-AD7625FMCZ/EVAL-AD7626FMCZ User Guide
DC TESTING—HISTOGRAM
Figure 21 shows the Histogram tab. The histogram can be used
to test the ADC for the code distribution for dc input, compute
the mean and standard deviation or transition noise of the
converter, and display the results. Raw data is captured and
passed to the PC for statistical computations.
To perform a histogram test, click the Histogram tab, then click
Single Capture or Continuous Capture.
A histogram test can be performed without an external source
because the evaluation board has a buffered V
ADC input.
To test other dc values, apply a source to the J3 and J5 inputs.
The signal may need to be filtered so that the dc source noise is
compatible with that of the ADC.
1
AC TESTING—HISTOGRAM
The histogram can also be used to test the ADC for the code
distribution for ac input, compute the mean and standard
deviation or transition noise of the converter, and display the
results. Raw data is captured and passed to the PC for statistical
computations.
To perform a histogram test, click the Histogram tab, then click
Single Capture or Continuous Capture.
An AC histogram requires a quality signal source applied to the
/2 source at the input J3 and J5 connectors.
REF
Figure 21 shows the histogram for a 20 kHz sine wave applied to
the ADC input and the results calculated.
The Histogram Analysis boxes, Label 1 in Figure 21, show the
various measured values for the data captured.
Figure 21. Histogram Capture Tab
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