Noise Test-Quick Start Demonstration - Analog Devices EVAL-AD7124-4SDZ User Manual

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NOISE TEST—QUICK START DEMONSTRATION
Click the NOISE TEST demo button to configure the device for
the noise test. The AD7124-4
demo, where the output data rate is set to 9.38 SPS, with the sinc
digital filter, full power mode of operation, and the REFIN1(±)
external reference selected. Gain and offset are the default factory
values following a reset.
To gather samples, change the Samples field to the number of
samples required value, then click SAMPLE to acquire the
samples from the ADC. Figure 24 shows an example of the
main window after running a noise test.
Reading Samples from the ADC
The evaluation board is set up to use the external 2.5 V on-board
reference (ADR4525). To read samples from the ADC, take the
following steps:
1. The value in the Refin1(+/-) field on the Configuration
tab is set to 2.5 V by default to use the external 2.5 V on-
board reference (ADR4525). If a different reference is used,
set the value in the Refin1(+/-) field accordingly. The
analysis results are based on the value set in this field.
a. When Single Run is selected from the drop-down list,
a batch of samples is read when SAMPLE is clicked,
with the batch size being set by the value in the
Samples box.
is now configured for the noise test
Figure 24. Example of the Waveform Tab After Running a Noise Test
EVAL-AD7124-4SDZ User Guide
b. When the drop-down box is set to Continuous Run,
the software performs a continuous capture from the
ADC when SAMPLE is clicked.
c. Click Stop to stop streaming data.
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2. Use the navigation tools within each graph to control the
cursor, zooming, and panning.
Waveform
The waveforms resulting from the gathered samples are shown
in this tab. The waveform graph shows each successive sample
of the ADC output (input referred). The indicators beside this
graph show the channels being converted. Navigation tools are
provided to allow the user to control the cursor, zooming, and
panning. The conversions can be displayed as codes or as volts.
Parameters such as peak-to-peak noise and rms noise are displayed
below the graph in the Analysis section for the current batch of
samples. If several analog input channels are enabled, each enabled
channel can be selected and the conversions on that channel
analyzed using Analysis Channel.
The conversion data can be saved in a text file from the File menu.
To save the data into an Excel file, right-click the waveform graph
and select Export Data from the drop-down list that appears. A
Save dialog box displays, prompting the user to save the data to
an appropriate folder location.
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