ADAU 1450 master and slave clock signals
Hello all,
I'm creating a new audio processing prototype, using the Adau 1450. It is based on a Adau 1701, with which I am reasonable familiar with :-) but not quite with the 1450.
We have three I²S signals (two from a ADC, one from a SRC) which should be processed by the DSP. They will be connected to the DSP on the inputs 0, 1 and 2.
The output is configured around a four channel DAC, using two I²S outputs (0 and 1). I would like the 1450 to be the clockmaster over LRCK and BCK. (for example, using output 0 as clockoutput for LRCK and BCK)
My question is: Is it sufficient to set one output of the DSP as clock-master, generating LRCK and BCK for my ADC, SRC and DAC ? I mean, it is not necessary to connect the LRCK's and BCK's from all used inputs and outputs of the 1450 on the PCB? So that I only have to route in the pcb the LRCK and BCK from output 0 to the ADC, SRC and DAC and from the ADC and SRC the I²S datasignals to the DSP SDATA-INputs and the I²S datasignals of SDATA-OUTputs 0 and 1 to the DAC?
For clarity I added a picture with connections to the DSP as I think it should be :-)
Hope to hear from one of you :-)
With kind regards,
Reini
Hi Reini,
This is certainly possible. The one thing that you may run into is a signal integrity issue with the shared lines, since you'll have three devices loading them down. However, the ADAU1450 has adjustable drive strength, and in my experience, can drive multiple devices just fine in most cases.
So, if you have some way of testing this type of connection first, with the ADAU1450 acting as a BCLK/LRCLK master for all three devices, I would recommend that you connect everything and check how the BCLK/LRCLK lines look with an oscilloscope, and verify that all the other chips are receiving correctly. If that all goes well, you should be good to go!
Regards,
Tyler
Hello Tyler,
Thank you for your quick response and sorry for my late ... I am on holiday and did not see your response earlier.
But I am very satisfied with your answer and we surely will monitor the clock signals to verify they have the correct shape :-)
Thanks again!
With kind regards,
Reini
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