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.

Interface PCM4222 to PC

Other Parts Discussed in Thread: PCM4222EVM, DIT4192, PCM4222

Hello,

I'm new to digital audio, so my question can look stupid, but...

I looking a way to connect PCM4222EVM via TOSLINK to PC.

My idea as follows : connect TOTX195 10Mb optical transmitter to DIT4192  TX+ (18pin), and adjust output format to Left Justified by SW3 FMT0 FMT1.

Is such approach correct ?

Do I need to disconnect AES3 decoupling transformers, or to use either buffer before optical transmitter ?

  • Hi Anatoli,

    The output format for the PCM4222 and the input format for the DIT4192 can be changed by DIP switch settings (table 9 and table 16 in the EVM users guide). These selections should match up. As for optical output, you should be fine with connecting the TX+ pin to the optical transmitter. The requirements for the digital input on the TOTX195 is 0V - 2V, and the DIT4192 TX output will be a minimum of VDD - 0.7V, VDD being 3.3 V so it should work. You should be able to remove R29 or R30, depending on which DIT you are using, to take the transformer out of the circuit. If you would like to keep the resistor in there then you can remove the transformer.

    Are you able to use an oscope to check that you have audio data going from the PCM4222 to the DIT4192 you want?

    Justin
  • Hello Justin,

    Thank you for very clear, and informative answer.

    Justin Bohr said:

    The output format for the PCM4222 and the input format for the DIT4192 can be changed by DIP switch settings (table 9 and table 16 in the EVM users guide). These selections should match up

    This is what I just did not noticed due to small experience with digital audio circuits. Well, I going to order PCM4422EVM from Mouser.

    Justin Bohr said:
    Are you able to use an oscope to check that you have audio data going from the PCM4222 to the DIT4192 you want?

    Yes, I'll be able, I have 100MHz scope.