UG-515 Datasheet, PDF (10/28 Pages) Analog Devices – Full-featured evaluation board

EVAL-ADAS3023EDZ
POWERING UP THE BOARD
The evaluation board, as configured from the factory, uses the
local LDOs for power where necessary. A ±15 V dc lab supply
must be connected to the board. Test points (yellow and white)
are provided for these external supplies.
Figure 9. Test Points
RUNNING THE SOFTWARE WITH THE HARDWARE
CONNECTED
The evaluation board includes software for analyzing the
ADAS3023. The EVAL-CED1Z is required when using the
software. The software is used to perform the following tests:
• Histogram tests for determining code transition noise (dc)
• Fast Fourier transforms (FFT) for signal-to-noise ratio
(SNR), SNR and distortion (SINAD), total harmonic
distortion (THD), and spurious free dynamic range (SFDR)
• Time domain analysis
This evaluation software should be located at
<local_drive>:\Program Files\Analog Devices\ADAS3023
Evaluation Software.
In order to launch the software, click
Start>All Programs>Analog Devices\ADAS3023 Evaluation
Software. You can then apply the signal source and capture
the data.
To uninstall the program, click
Start>Control Panel>Add or Remove Programs>Analog
Devices ADAS3023 16-Bit, 8-Channel Simultaneous
Sampling Data Acquisition System.
Evaluation Board User Guide
Refer to Figure 10 to Figure 19 for further details and features of
the software.
DC TESTING–HISTOGRAM
This 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.
To perform a histogram test, select Histogram from the test
selection window and click on Start. To test dc values, apply a
source to any of the analog inputs IN[7:0]_I either via test
points or P1. 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
This tests the traditional ac characteristics of the device and
displays a fast Fourier transform (FFT) of the result. As in the
histogram test, raw data is captured and passed to the PC
where the FFT is performed displaying SNR, SINAD, THD,
and SFDR. The data can also be displayed in the time domain.
To perform an ac test, apply a sinusoidal signal to the analog
inputs. Low distortion, better than 97 dB, is required to allow
true evaluation of the part. Note than many bench-top signal
generators are at best 14-bit digital to analog converter (DAC)
outputs and the ADAS3023 is 16-bits.
Simply connecting a source of this resolution results in what
would appear to be incorrect displayed results (numerous
harmonics and spurs). To alleviate this, one possibility is to
filter the input signal from the ac source. There is no suggested
band-pass filter, but consideration should be taken in the
choice. Note that a passive filter also provides dc blocking and if
any dc common mode is to be preserved, it would have to take
place after the filtering.
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