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PCM9211: eARC

Part Number: PCM9211

Hello

Customer found that latest (rev B) data sheet of PCM9211 add the

eARC compatibility feature.

Also we can see white paper as following

www.ti.com/.../sbaa300a.pdf

Here is the question from customer.

Q1

What is the background you add the 'eARC' description?

It seems  Electrical characteristics is not changed.

Q2

Is following understanding correct?

* PCM9211 can receive eARC from  x 2 coax input. ( If more than x 2 input, multiple PCM9211 is necessary)

* PCM9211 receive x2ch eARC when it were PCM data,then decode it to I2S data by DIR.

* PCM9211 can not decode compressed audio of HDMI2.1signal( like as dts:X ) to I2S.

Q3

What is your recommended device which decode HDMI2.1 eARC signal ?

( My understanding is PCM9211 can not decode dt:X, but when  it were 2 channel PCM, can decode from PCM to I2S)

Best Regards

  • Hi Shibatani-san,
    Below are my comments wrt to PCM9211 and ARC compatibility -

    1. What is the background you add the 'eARC' description?
    As you may know, ARC stands for Audio Return Channel which allows for digital audio (IEC 60958 / SPDIF) transmission and reception on existing HDMI connectors. To validate that PCM9211 can reliably handle the ARC signal (single-ended), we verified the PCM9211 DIR block to make sure it can handle much lower value of min Vpp values and changed the same in the DS to make sure it's compatible w. ARC signals.

    2a. PCM9211 can receive eARC from x 2 coax input. ( If more than x 2 input, multiple PCM9211 is necessary)
    YES. Only two inputs have built-in coaxial amplifiers (RXIN0 and RXIN1) and are both Single-ended inputs which should be used as outlined in the tech note.

    2b. PCM9211 receive x2ch eARC when it were PCM data,then decode it to I2S data by DIR?
    That's correct. If the data is uncompressed PCM or Linear PCM, DIR can decode the same and convert the stream into I2S.

    2c. PCM9211 can not decode compressed audio of HDMI2.1signal( like as dts:X ) to I2S?
    CORRECT. That's the right understanding as we do not have any decode engine implemented in PCM9211.

    3. What is your recommended device which decode HDMI2.1 eARC signal ?
    If you are specifically looking at the Dolby Atmos type audio stream, 66AK2G audio SoC would be a good one to consider.

    Best regards,
    Ravi
  • Dear Ravi san

    Thank you for your answer so quickly !!!

    Please let me confirm because my customer had a question.

    Question( confirm)


    Can PCM9211 handle HDMI2.1 eARC  signal which is differential + common signal?

    We see PCM9211 can handle ARC which is single ended and PCM9211 DIR input is 0.15Vpp(min) in the latest data sheet.

    Background


    My customer says single end ARC swing level Min 0.2Vpp is

    for HDMI Specification Version 1.4b.


    (P378 HEAC Table2-15“Minimum input (peak-to-peak):See IEC 60958-1”)

    My customer also says eARC signal is differential+common,

    which is in  HDMI Specification Version 2.1  P295 9.5.1.1  Audio Transport and Data Communications.

    Would you please advise ?

    Best Regards

  • Hi Shibatani-san,

    PCM9211 can only support Single-ended inputs and as a result, it cannot support differential eARC signal. Hence PCM9211 can handle ARC signal which are SE and will not be able to handle eARC differential signals.

    Thanks.


    Best regards,
    Ravi

  • Dear Ravi san

    Thank you for your answer!