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PCM1800: ANC system design check

Kai Lai
Expert 7336 points
Part Number: PCM1800

Hi Team,

My customer now is target to design a ANC (Active Noise Cancellation) system, and they are searching our ADC / DAC solution, need expert to provide the recommendation and technical topic reply here.

Thanks for your support in advance!

Can you help to check what are the TI hero part of ADC/DAC for below requirement ? 

-------   Requirement spec   ---------------------

  1. Group delay: <120us latency @48Khz sampling rate (ADC+DAC only, SAR ADC is recommended)
  2. ADC/DAC bit resolution: >= 14bit(applying audio scope)
  3. Port #:  ADC: 4 input (support dual channel sampling simutaneously, at least)
  4. Port #:  DAC: 2 output

<audio path> as below

BR,

Kai

  • 0
    TI__Mastermind 29745 points

    Hi Kai,

    Questions:

    • Are they looking for CODEC or just ADC and DAC?
    • Are they implementing the ANC algorithm outside of the audio devices for example using external DSP?
    • Support dual channel simultaneously from 2 different Serial Audio Interface (SAI) or single SAI?
    • Can we request a block diagram?

    Regards,

  • 0 in reply to pdjuandi
    Prodigy 50 points

    Dear all:

      The reply is as following

    • Are they looking for CODEC or just ADC and DAC?
      • >> We also look for CODEC but group delay(<120us@48k) all cannot meet our requirement.  Is there any suggestion? 
    • Are they implementing the ANC algorithm outside of the audio devices for example using external DSP?
      • >>Yes, using external DSP
    • Support dual channel simultaneously from 2 different Serial Audio Interface (SAI) or single SAI?
      • >> If use single SAI.  Will it impact sampling time simultaneously.  or It's only transmission time impact?
    • Can we request a block diagram?
      • >> block diagram will be like audio path illustration. 

    Thanks!

    BR/Elvin

  • 0 in reply to Elvin Shih
    TI__Mastermind 29745 points

    Hi,

    The current codec has group delay greater than 120us. I'm checking internally if we have ADC/DAC that will meet your requirement.

    Single SAI will have the same sampling for both channel.

    Regards.

  • 0 in reply to pdjuandi
    TI__Mastermind 29745 points

    What is the end application that needs such low latency? 

  • 0 in reply to pdjuandi
    TI__Expert 7336 points

    Hi PD,

    This is a education cooperation case, the education side requires such a specification.

    I guess that is for the ANC purpose ? In order to implement the noise cancelation, it need the real time sampling signal ? Is this make sense?

    Or if for ANC system, what kind of the latency here in your experience before ?

    Thanks!

    Kai

  • 0 in reply to Kai Lai
    TI__Mastermind 29745 points

    Our device currently running like 350us or more, I have never seen such low group delay requirement for ANC.

    We might not be able to support that with current device.

    We have newer devices coming later this year below 120us, what is their timeline and the company and application details in a private message?

    Regards.