• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Answers 1 answer
  • Subscribers 30 subscribers
  • Views 202 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DIT4096: DIT4096 transmitter with PCM1808 ADC

ionut remus Remus
Prodigy 25 points
Part Number: DIT4096
Other Parts Discussed in Thread: PLL1708, PCM1808

Tool/software:

Hello,

I have made the project from the Schematic added here. Created a PCB and after powering it on it seems that it doesn't work.
After reviewing several times the connections i came t the conclusion that something is wrong with the schematic itself and tried somehow to understand more and i definitely need some help as after me it seems that everything is fine.
Can someone help with a review and advice?  I really don't know what is wrong or what i am missing!
Please note that for the RST pin i used a MCP130 that will handle the reset, and some decoupling caps are missing for simplicity.

Thank you!

  • 0
    TI__Mastermind 30711 points

    Hello,

    I assume you are using the ADC in master mode and want to send  the  generated I2S signals form ADC to AES3 format .  Have you measured to see if  the I2S signals  that are coming out of ADC  are correct? Also note that SCKI for ADC has to be provided so it can be used internally.

    Please describe the issue in more details: What is working fine and what is not working?  I understand that the system as whole is not working but can you explain what signals you have tested so far ,  what is working and what is not working as you expected.

    Kind Regards,

    Arash 

  • 0 in reply to Arash Loloee
    Prodigy 25 points

    Hello  ,

    What i want to do is exactly what you assumed. I want to send the ADC audio signals via coaxial cable (maybe toslink, stil not sure yet) to a DAC.
    Unfortunately my scope (3 in 1) broke down a couple of days before my tests, another one it's on his way back to me, but until then (mabe a week or so...) i don't have any means of measurements, except a simple plain multimeter (as simple as it can get, bought from the local store for emergency purpose). All i can check is that SCKI has around 1V when no input signal is present on the ADC input and around 0.3V when signal is applied. The rest are 0V, maybe also the multimeter cannot measure correctly.


    "Also note that SCKI for ADC has to be provided" - stupid me.......i was so focused on to check mistakes that i totally left this part out.... It seems that also the DIT4096 needs one....  Rookie mistake as it's the 1st time i am using DIT4096 (or any similar transmitter).

    Thank you!


    LE: A  PLL1708 will be good enough if i use SCKO1 for the configured 256fs ADC/transmiter? Again maybe a bit stupid question but i never doubt with something similar...
    As well can i use the same clock source to provide the clock for more than 1x PCM1808/DIT4096. (in my theory should be double)


  • 0 in reply to ionut remus Remus
    TI__Mastermind 30711 points

    Hello, The lack of master clk in your schematic is the main issue. Unfortunately for clks you have to have scope so you can verify the full spec of the clks. Especially if ADC is set in master mode , you have to make sure the generated  I2S ( from ADC) is what you think it is -before you send it to DIX device.

    I am  not familiar with PLL1708I but it seems it  is a  good option for SCK.

    If you still have any issue after providing correct clocks, let me know.

    Regards,

    Arash

  • 0 in reply to Arash Loloee
    Prodigy 25 points

    Hello  ,

    I agree with you, i just was hoping that i can solve this a bit more blindly, without to much hassle, but i guess i will need to wait to have my scope to arrive and then start troubleshooting and order some components, like the PLL1708 as i don't have a stock!

    If you are kind enough, please let me know your thoughts, on how you will do it in theory. This way i will have the time to prepare and do my research as well

    Regards,
    Ionut Spoiala

  • 0 in reply to ionut remus Remus
    TI__Mastermind 30711 points

    Hello,

    Once you have the- master clk fed to ADC, I don't think you should have any issue . ADC is very straight forward and you should  be able to verify the ADC conversion first and once it is stablished I don't think you should have any problem with the DIX device. Nevertheless scope has to be handy to move on.

    Regards,

    Arash

  • 0 in reply to Arash Loloee
    Prodigy 25 points

    Hello,

    It looks like my scope is not coming too soon, therefor i won't continue with the troubleshooting until i have the scope in my hands.
    I am fairly sure, based on the replies here, that everything will be fine after the SCK signal provision will be done, therefor i will consider this thread closed, as there is no reason to have it open for such a long time.

    Best regards and thank you for the help.