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Are PCM2705, PCM2705C USB Audio DAC IC supported by mobile OS such that: iOS and Android?

Other Parts Discussed in Thread: PCM2705, PCM2705C

Hello,

 

Are PCM2705, PCM2705C USB Audio DAC IC supported by mobile OS such that: iOS and Android?

 

Unfortunately but the chips webpages contains no that information.

http://www.ti.com/product/PCM2705C/description

http://www.ti.com/product/PCM2705/description

 

Regards,

Radosvet B.

  • Hello Radosvet,

    In what way do you mean supported?

    We do not offer software or GUI development through a mobile device if that is what you mean.

    Regards,

    Matt

  • Hello Matthew,

    It’s mean that:

     

    1.   Will the PCM2705, PCM2705C USB Audio DAC ICs correct operate with the iOS, Android based devices (smartphones, Apple iPods and others) thru the USB interface?

     

    2.   The PCM2705, PCM2705C USB Audio DACs need some drivers or etc. to work the iOS, Android OS with?

     


    Regards,

    Radosvet B.

  • Hi Radosvet,

    The USB Audio DAC’s conforms to USB standards. I would suggest reading the datasheet fully to make sure it will work for your application, but, if the source device can supply the necessary data lines and correct clocking, then there should be no issues.

    The datasheet also states that it does not need a dedicated device driver.

    Best Regards,

    Matt

  • Hi Matt,

    The chip is working OK in my application with the traditional PC already.

     

    Do you mean that PCM2705 (-C) will operate with the Apple iPod Touch 5 USB-OTG host output (for example) to make the analog audio/spdif signal from the USB output digital audio?

     

    How can I ensure in this assumption?

     

     

    There are no any mentions in the datasheet concerning mobile OS (iOS, Anfroid) using.

     

     

    Or rearranged question: the mobile OS (iOS, Anfroid) supports the PCM2705 (-C) operation or not?

     


    Regards,

    Radosvet B.

  • Radosvet,

    To ensure that the iPod USB-OTG will work you need to get the technical specifications from Apple. It may be readily available on the web. You will have to verify that the communication protocol and from the OTG-USB will match the standards that the PCM2705/C uses. Since the iPod allows for USB connectivity there should be no isues, but you need to check pin for pin and compare the iPod to the PCM2705 datasheet.

    Again, for the phone to work with this part, you need to research the communication protocols for these different phones.

    Regards,

    Matt

  • Hi Radosvet,

    PCM2705C will work with every operating system which support USB audio class 1.0. Some Android phones will work but some of them doesn't include kernel module with USB audio support.

    I don't know if iOS includes support for USB audio cards but the easy solution is to test it with concrete model.

    It is probably waste of time to ask Apple or Android phone dealers...

    You must test it by yourself. On android phones you can check the situation in terminal with command "dmesg". You will see if kernel recognize USB soundcard or not after USB insert.

  • Thank you Pavel, thank you Matt.

     

    1.   Are the USB Audio Class 1 (UAC1) device and USB Audio Class 2 (UAC2) device can be forward (and back) compatible?

     

     

    2.   What is the USB Audio Class of the IC PCM2705?

    What is the USB Audio Class of the IC PCM2705C?

     

    UAC1 or UAC2 or the UAC is not defined at all?

     

    I explored the document sbfa019 Key Differences Between the PCM270x and PCM270xC (www.ti.com/lit/an/sbfa019/sbfa019.pdf) and their datasheets but have not found the clear answer.

     

     

    3.   Is the USB Audio Class defined (or set) for the ICs PCM2705 and PCM2705C strongly, definitely at all?

    The PCM2705C datasheet states: * USB 1.1 Descriptors with USB Audio Class Support*

    It is unclear to understand.

    The PCM2705 datasheet states no USB Audio Class information.

     

     

    4.   Will the ICs PCM2705 and PCM2705C operate correctly with the USB Audio Class 1 (UAC1) device?

     


    Regards,

    Radosvet B.

  • Hi Radosvet,

    1. UAC1 device usually works with UAC2 driver. UAC2 device will not works with UAC1 driver. Like in windows. You must install UAC2 driver from 3rd party vendor. Usually UAC2 devices can be switched to UAC1 mode with limited functionality (not support for 192kHz or 32bit).

    2. It is UAC1 compliant. Change to version C was mainly because Microsoft changed volume scale from Windows Vista and soundcards with older versions of PCM2705 can't be certified with Windows logo. Also there was a little modification for USB 2.0 certification but still with full speed, not high speed.

    3. Audio class can't be probably modified and is not needed. Chip will work with UAC1 and 2 compliant devices.

    4. Yes, it could work with UAC1 compliant devices. It depends on concrete device if all functions will work correctly. For example on linux are troubles with HID buttons, when you have more soundcards. Buttons change volume of another or all soundcards. This situation is about USB/HID, audio system implementation in concrete operating system.

    Best regards, Pavel.

  • Hi Pavel,

     

     

    Thank you for the clarification.

     

     

    Regards,

    Radosvet B.