CDB5471 Datasheet, PDF (16/26 Pages) Cirrus Logic – Evaluation Board and Software

CDB5471
(from both channels) and it will update the on-
screen results of both channels after calculating the
results on each successive set of 4000 samples.
The results that are displayed on this screen are
therefore updated after each computation cycle.
Note that the results in the very first computation
cycle (after the “START” button has been activat-
ed) will not be valid. Accuracy of the Mean, Std.
Dev. and RMS results will increase as the “Sam-
ples to Average” value is increased.
The user should understand how to interpret the
values that are displayed in the array of number
boxes in the Conversion Window. For CDB5471,
only the results displayed in the “Voltage 1” and
“Current 1” rows are valid. The result values
that are displayed in these numeric output boxes are
all expressed on a normalized scale. The highest
value (0.999...) represents the highest digital output
code that can be issued from the CS5471 (which is
+32767), while the lowest value -0.999... repre-
sents the most negative output code that can be is-
sued from the CS5471 (which is -32768). This is
because the CS5471 issues instantaneous output
codes as two’s complement 16-bit words. There-
fore, the range of values that can be returned from
the CS5471 are between -32768 and +32767. The
CS5471 issues instantaneous data, and every com-
putation cycle, the software computes/displays the
quantities which are described below:
Figure 5. Conversion Window
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DS480DB1