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ADAU1462 a sample rate of 192 kHz

I'm working on a project  using ADAU1462 and AD1938 to du  a sample rate of 192 kHz  but there are a question ---  ripple

bu use 48 kHz sample rate is very good

I use sigmastudio

and  AD1938  also Configured to 192kHz

I am very troubling, How can i Configured ADAU1462 to 192kHz sample rate

  • i am not sure, if you are using the ADAU 1466Z evaluation board. If you are using the evaluation board then you can only use 44.1 kHz or 48 kHz. It says there if you try to use 192 kHz you will get distorted results

    as its mentioned here in following pdf in page 18, AD1938 codec

    www.analog.com/.../EVAL-ADAU1466Z_UG-1135.pdf

  • HI Skhan,

       The results are from the customer's boards. 

  • The sample rate setting in SigmaStudio up at the top of the page is to tell the compiler to produce code for a certain sample rate. Some of the cells need to know what it is. But SigmaStudio has no way to know what the sample rate actually is in hardware.

    You have to set the core start pulse to the correct clock. The PLL has to be setup properly for the incoming master clock frequency and then the master clock needs to be the correct frequency. This is what sets up the sample rate.

    Since you have setup Serial Output Port 0 as a master, then connect a scope to the LRCLK output and see what it is producing. Is it 192kHz?

    Then you need to check the Start Pulse register to see if it is set properly. The clocking structure is very flexible so it is difficult for me to say exactly what you need to check.

    I guess first you can put a scope on the CLKOUT pin and see what you are getting there. In the Clock Control tab of the Hardware Configuration page you can set the MCLK OUT setting. If it is set to Base fs *256 then you should be getting 12.288MHz on the clock out pin. If this is true then the master clock and PLL are all set correctly.

    Then you need to set the Start Pulse to Base_FS * 4, 192kHz. This determines the sample rate of the core.

    You do need to look at the clocks to the codec to see if it all looks good.

    Dave T