I wonder if ADC and DAC that at EVAL-ADAU1452MINIZ can work synchronously ?

I wonder if ADC and DAC that at EVAL-ADAU1452MINIZ can work synchronously ?

  •      Hello zhang123,

         From your other post, it appears that you wish to synchronize a "click track" to incoming audio. This may or may not work depending upon the application you envision, as well as your timing accuracy need.  The ADAU1452, the AD1938 codec (on the same eval board), and SigmaStudio can all simultaneously input and output disparate signals for ADC and DAC -- even though these inputs and outputs are sometimes shown as stereo pairs.  However, the delays involved may exceed what your application will tolerate.




         The AD1938 applies digital interpolation filters to both its ADC and DAC -- this allows you to input and output analog signals without providing your own brick-wall analog filters before and after the chip.  These filters have input and output delays totaling about 1 mS at 48 KHz -- for the exact input and output group delays, see page 6 of its data sheet.  The ADAU1452 may also have very short delays between I2S I/O and its core -- I don't know exactly how much, but these delays total about three samples in the ADAU1701.


         So, there's a delay before the ADAU1452 knows an input signal is there, and another delay between your desired output signal and the DAC output.  The delays match well between channels, so sometimes your application allows you to use this delay matching to your advantage.



         Best regards,


         Bob

  • Thank you KJBob,

    if I don't do filtering in both ADC and DAC,could they work more synchronously?Could I ignore the time in both without filtering.

    Sincerely,

    Zhang

  • Hello Zhang,

    What exactly are you trying to synchronize?

    Dave T

  • Hello Dave,

    I think the synchronization of EVAL-ADAU1452MINIZ is not a problem.However , when I want to use it to record music ,I don't know how to make the input signal transfer to my PC through the EVAL-ADUSB2EBZ and USBi.There is a RAM in ADAU1452,if I put a Block Input Buffer in my Sigmastudio project,then what should I do?

    Cheung

    sincerely

  • Hello Cheung,

    It is not possible to use the ADUSB2EBZ to transfer the audio over the USB connection. It is only for control and some lower rate data back to SigmaStudio. The easiest way to get audio to your PC from the eval board is to use the SPDIF output and obtain an SPDIF interface for your PC. You can only transfer stereo audio.

    Another way would be to use a DAC evaluation board and come out analog to your PC.

    Dave T