Clocking ADAU1772 other than 24.576 or 12.288 MHz

Hello Sal,

You should be fine running it with a 24 MHz crystal. 48kHz fs will be 46.875 kHz if you set it as a master.

The internal 192 kHz DSP core rate will now be at 187.5 kHz so there will be slightly fewer MIPS. Then if you do use the serial ports to communicate to external devices then just use it in slave mode and feed it 48 kHz and the ASRC will do a fine job converting the internal rate to 48k.

Dave T

DaveThib I see. Our original intent was to keep the ADAU1772 the master and an external MCU as I2S slave. The sample rate for this serial communication is 32 kHz for us, which would turn into 31.25 kHz. Is it not possible to keep the codec the master in this scenario?

Hello Sal,

You can set the 1772 to be the master and set the serial port for 32 kHz fs and you will be fine. I just mentioned that if you still wanted to get to a "standard" sample rate, that the ASRCs would do it just fine but you would have to have the 1772 serial ports running as slaves. So if 31.25 kHz fs is OK for your application then yes, you can do it.

Dave T

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EZ Admin