ADAU1467, Sigma Studio v4.7 different Level detectors show different signal levels
I am currently testing a custom board using ADAU1467 and ADAU1361. Currently I want to verify that the DAC of ADAU1361 behaves as expected. Therefor I create a test tone (sine 1kHz, 0dB) with ADAU1467 and feed to ADAU1361 by I²S.
In order to be sure that ADAU1467 outputs 0dB FS signal to DAC, I added a level detector into the schematic. The sine generator is set up to create a 0dB sine. But the level detector shows -3dB.
I tried several level detectors and all show different levels. Quite confusion.
See this screenshot:
I attached my Sigma Studio project.
Level Detector Test.dspproj
Could somebody please comment on this and clarify what's going on? How can I read the correct level?
Audio Signal Processors
software
adau1467
level detector
Integrated/Special Purpose A/D Converters
sigmastudio
SigmaDSP Audio Processors
Audio CODECs
Sigma Studio v4.7
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Hello andreas.ru,
These level detectors calculate the RMS value and display the same which is -3dB (0.707) for a 0dBFS sinusoid. So, this is expected.
If you want to see 0dB as is then use a peak envelope like below.
Regarding different level detectors, please have a look at the wiki explanation here.
Kindly do reply if you still have questions.
Regards,
Harish
Thanks a lot for your quick and detailed reply. It is clear now.
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