UG-484
EVAL-ADAS3022EDZ User Guide
Rev. A | Page 16 of 32
HISTOGRAM TAB
The histogram is most often used for dc testing or ac testing,
where a user tests the ADC for the code distribution for dc input
and computes the mean and standard deviation, or transition
noise, of the converter, and displays the results. Raw data is
captured and passed to the PC for statistical computations.
Figure 29 shows the Histogram tab.
To perform a histogram test,
1.
Select the
Histogram
tab.
2.
Click
Single Capture
or
Continuous Capture
.
DC Testing
To test other dc values, apply a source to the selected analog
inputs IN[7:0]_I via test points or P1. It may be required to
filter the signal to make the dc source noise compatible with
that of the ADC. Note that 0805 and 0603 SMT pads are
provided in each signal path and can be used for filtering the
source, if necessary.
AC Testing
Figure 29 shows the histogram for a 1 kHz sine wave applied to
the analog inputs IN[7:0]_I via test points or P1 from a quality
precision signal source, such as Audio Precision. It may be
required to filter the input signal from the ac source. There is no
suggested band-pass filter, but consider all choices carefully.
The
Waveform Analysis
(Label 1) chart displays the various
measured histogram values for the
ADAS3022
.
Figure 29. Histogram Tab
1
1064-
128
1
