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Thread: SPDIF and OPTICAL (Toslink) Pinout/Schematic

  1. #1
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    SPDIF and OPTICAL (Toslink) Pinout/Schematic

    Hello,

    Can someone please verify the schematic below looks like all we need to successfully implement an Optical / TOSLINK IO with T4.1 (other than software)?

    Click image for larger version. 

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    Using FCR6842032R and FCR6842032T made by CLIFF Electronic Components Ltd.

    Frank Boesing has linked to some TOSLINK / SPDIF circuits on his github page. I will quote him below to contribute to the discussion/documentation here.

    I'm also going to link to the design tool below.

    https://www.pjrc.com/teensy/gui/?info=AudioInputSPDIF3
    https://www.pjrc.com/teensy/gui/?inf...dioInputSPDIF3 <- pin 15
    https://www.pjrc.com/teensy/gui/?info=AudioOutputSPDIF
    https://www.pjrc.com/teensy/gui/?info=AudioOutputSPDIF2
    https://www.pjrc.com/teensy/gui/?info=AudioOutputSPDIF3 <- pin 14

    If done correctly, it seems that optical is easier to implement than SPDIF. I think optical might be cheaper because of the transformer and/or buffer drivers. I imagine optical is almost as ubiquitous as SPDIF? An external converter is pretty easy to come by if not, I think.

    Can someone please verify my optical jack schematic? Also, will this work with ADAT?

    Jay
    Last edited by JayShoe; 03-16-2022 at 05:14 PM.

  2. #2
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    Hmm, Murphy's law and datasheets.
    For the receiver I'd suggest that Vcc (pin 3)is the device's +V supply pin and pin 1 is Data OUT.
    For the transmitter I'd suggest that Vcc (pin 3)is the device's +V supply pin and pin 1 is Data IN. Also suggest 100R between T4's SPDIF TX and DATA IN, as close as possible to T4 to absorb overshoot/ground bounce.

  3. #3
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    Hmm, Murphy's law and datasheets.
    Yes you are correct. I had been drawing various circuits with different parts and wound up here. It's strange that the two products in the same series are so different. I think the following is right.

    FCR6842032T (1=GND, 2=VCC, 3=VIN)
    FCR6842032R (1=VOUT, 2=GND, 3=VCC)
    VCC = 5V

    Click image for larger version. 

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    Also suggest 100R between T4's SPDIF TX and DATA IN, as close as possible to T4 to absorb overshoot/ground bounce.
    Thanks for the tip! Here is a 100R resistor in series next to the Teensy.

    Click image for larger version. 

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    Last edited by JayShoe; 03-17-2022 at 02:33 AM.

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