• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 33 subscribers
  • Views 1959 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.

SN65LVDS1 and SN65LVDS2 as a driver and receiver for AES/EBU and SPDIF digital audio signals?

Sergei Vereskov
Intellectual 510 points
Other Parts Discussed in Thread: SN65LVDS2, SN65LVDS1

Hello!

Is it possible to use SN65LVDS1 and SN65LVDS2 as a driver and receiver for AES/EBU and SPDIF digital audio signals?

If Yes, then please advise some kind of reference design if there exist one.

  • 0
    TI__Mastermind 20820 points

    Hi Sergei,


    I am not that familiar with the SPDIF standard so if you could provide me with some of the specs it would help me determine if these devices would be a good fit for your application.

    Just from doing a quick search on the web I was able to find out that SPDIF uses 75ohm coaxial cable and termination. LVDS is a 50ohm differential transmission which is defined in the LVDS standard (TIA/EIA-644). This standard is easily found on the web if you care to do further research into LVDS signaling.

    The SN65LVDS1/2 are simple buffers so as long as the SPDIF voltages are within the specified voltages in the data sheet there should be no issue with implementing them in an audio design. There is a work around as well for converting from 75ohm termination to 50 ohm termination so this should be a none issue.    

    I am not aware of a reference design at this point that exist for a SPDIF application using an LVDS buffer.

    Please provide me with any additional information that you can and I will do my best to help out!

    Regards,

    Michael Peffers

    Analog Application Engineer

  • 0 in reply to Michael Peffers
    Intellectual 510 points

    Hello, Michael !
    Thank You for Your answer.
    I think I'll solve it by myself, but I need one clarification about SN65LVDS1 and SN65LVDS2.
    In its datasheet in the RECOMMENDED OPERATING CONDITIONS it is said:
    "|VID| Magnitude of differential input voltage 0.1....0.6 V"
    but at the same time in the next line:
    "Input voltage (any combination of input or common-mode voltage) 0 ... VCC–0.8 V"
    Isn't it a contradiction?

     

     

  • 0 in reply to Sergei Vereskov
    TI__Mastermind 20820 points

    Hi Sergei,


    The SN65LVDS1/2 can have a VID (input differential voltage) that ranges from 100mV to 60mV. In combination with the common mode voltage the input can range from 0 to Vcc-0.8V. Example:

    VCC = 2400mV (min VCC)

    VCC-0.8 = 1600mV (max allowable VIH with selected VCC)

    VID = 400mV

    VCM = 1200mV

    VIH = 1600mV

    VIL  = 1000mV

    Hope that helps, let me know if you have more questions.

    Regards,

    Michael Peffers

    Analog Applications Engineer

  • 0 in reply to Michael Peffers
    Intellectual 510 points

     Hello, Michael !
    Thank You for Your answer.

    If I use SN65LVDS2 ( receiver ) in a single-ended mode with negative input ( B ) grounded and 75 Ohm between positive input ( A ) and ground, then what is the allowed voltage range that can be fed into its positive input ( A )?


    On the other hand, if use SN65LVDS1 ( driver ) in a single-ended mode, using only its positive output ( Y ), then what  voltage range will be present on this positive output ( Y ) if input ( D ) is +3.3V CMOS and the load is 150 Ohm to ground?