Adau1467 signal level increases above a bitrate of 192 khz
Hi,
When I use the ASRC with an inputsignal above a bitrate of 192 khz, the signal level seems to go up (3 or 6 dB). Suspect that signals values are shifted 1 or 2 bits to the left, but not quite sure what causes this. Everything on the eval board is running at 192 khz.
So why does this happen, and what might me a solution/workaround?
Many thanks,
Mark
Audio Signal Processors
Audio Products
hardware
adau1467
SigmaDSP Audio Processors
Hello Mark,
Chances are this is a signal integrity issue and timing margin issue. Do you have the drive strengths set to max?
Take some screenshots of your I2S clocks and data then you can see how close you are coming from a timing perspective. Running at 192kHz is always a challenge and the PCB layout has to be done very well.
If you are using eval boards and using wires to jump over to other eval boards then that is always difficult to get quiet with no clicks or pops and with no bit shifts.
Dave T
I can't control drive strength as this is on the input side, or do I misunderstand?
Also using a rather short flatcable (lines with signal separated by lines with gnd) coming from an Amanero USB board.
Still.. I had a look at the clocking and the data line rising/falling edges fall well within spec.
It has to be something else...
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