• AD1974 differential audio input impedance

    Hi All,

    Is there any differential impedance requirement (like 100 Ohms) that needs to be followed in the PCB layout while routing the audio inputs to AD1974 ADC? Our circuit is similar to AD1974 EVM where OP275 converts single ended to differential audio…

  • RE: Use AD193x driver for AD1974


    Thanks for your help! Eventually I've been able to put together a running AD1974-driver for the beaglebone. That is, the AD1974 gets registered as an ALSA soundcard, however, I'm yet to actually capture audio from the AD1974.

    The first problem…

  • RE: ADAU1442 Clocks

    Hi Guy,

    If the master clocks are not synced then you must use the ASRCs. As for the AD1974 you must use the same master clock as the ADAU1442 with the AD1974 as slave. Otherwise you could make the AD1974 a master and use the input ASRCs of the ADAU1442…

  • How to configure AD1974 through SPI


    I am using AD1974 on self designed board.

    I am trying to configure AD1974 with ADSP-21371 through SPI.

    The AD1974 uses 24 bits wide SPI, from datasheet:

    The SPI control port of the AD1974 is a 4-wire serial control port. The format is similar…

  • AD1974 Design Queries

    Hi Everyone

    I am planning to use AD1974 in my deisgn and I have a few queries regarding that.

    1. Can I use AD1974 for broadcast applications?

    2. I am planning to use 4 AD1974 devices to capture 8 stereo inputs. Can anyone confirm if this is possible…

  • RE: How can I connect electred mic. to AD1974 Eval board


    To use an electret microphone with the AD1974 evaluation board, you will need to power the electret mic per its specification. Then, connect the ground pin of the electret to a GND test point on the AD1974 eval board. Place a DC-blocking capacitor…

  • RE: AD1974 Daisy Chain


    I am also planning to use AD1974 in my design to capture 8 stereo channels. For this we have to use 4 AD1974, I wanted to use the 4x AD1974 daisy chain diagram you have shared earlier in this post. But the clarity is not good. Can you please…

  • RE: TDM for 16 audio channels. What's the best way?

    Hi Dave,

    Thanks for the quick response!

    I just want to make sure I'm understanding this correctly.

    For the AD1938/AD1974 solution we'd have common LRCLK and BCLK to all four chips, then have a two pairs of data lines, data out from the codecs to the…

  • (case#: S13KK00233)  SIGMA DSP ADAU1701/1702  proposal for xxxx.

    Our customer xxx doesn’t understand why the AD1974 is not necessary ( as you suggested in your first answer) … they planed to use it in the way that they had already explained:

    “Our customer xxxx ( specialist in Megaphones ) is thinking about using …

  • RE: AD1974 data format

    Hi Sander,

    I would like to clarify your issue: What format of data are you using between the AD1974 and the ADSP-21261? Can you post your register settings for the AD1974? Or does your question refer to the buffered DMA data?