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  • TI Thinks Resolved

ISO1212EVM: Looking for equivilant EVM for 8 channels of isolation at RS-422 signal level

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Replies: 5

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Part Number: ISO1212EVM

Hi,

I"m trying to filter some noise from a pulse generating system, up to 270KHz, 5us width.  I purchased a ISO1212EVM optical isolator but the levels to trigger this board are too high, it starts outputing voltage at 19V input. 

Does anyone have an idea for a chip I could use?  Hopefully with an Eval board as my setup is temporary.

Thanks

Jim

  • Hi Jim,

    The device ISO1212 is meant for applications with 24V or higher voltage digital inputs which are typically used in factory automation and other similar applications. This device will not be suitable to be used with RS-422 signals.

    Could you please elaborate on the voltage levels that the pulse generating system is going to output? Based on your inputs, I can recommend a suitable device and the evaluation board to use.


    Regards,
    Koteshwar Rao

  • In reply to Koteshwar Rao:

    Hi Jim,

    Please do share the requested information to enable us make device and EVM suggestions for you. Thank you.


    Regards,
    Koteshwar Rao

  • In reply to Koteshwar Rao:

    Hi Jim,

    I hope you have found a solution that meets your requirement. If you are still looking for an EVM that supports multi-channel isolation of digital CMOS signals then you look at using an EVM from ISO77xx family of devices, the ISO7741EVM. This EVM supports 4-channels and the device the EVM comes with is ISO7741 (3 channels in one direction and 1 channel in opposite direction). If you require a different channel configuration then you can replace the device ISO7741 on EVM with any ISO77xx device of your interest for evaluation. I hope using two of such EVMs meets your requirement for 8-channel isolation.

    Hoping that this answers your question, I will go ahead and mark this E2E post as closed. Please reply back or create a new post if you have more questions. Thank you.


    Regards,
    Koteshwar Rao
  • In reply to Koteshwar Rao:

    Hi,

    My signal levels claim to be "ANSI standard TIA/EIA-422-B, differential line drivers."  Most of them are positive going though one of the differential signals is negative.

    I"m trying to use this chip to isolate ground loop noise from another system where I'm receiving the trigger.  I've tested a Vishay chip that seems to trigger ok for my application.  I couldn't find a TI equivalent and was a bit rushed for a solution. 

    Jim

  • In reply to Jim Lewandowski42:

    Hi Jim,

    Thanks for your inputs. We a few isolated RS-485 devices that can also be used for RS-422. Most of these devices are available in a single full-duplex / half duplex transceiver options. Please do have a look at the below device and its associated EVM and let us know if this meets your requirement, thanks.

    www.ti.com/.../
    www.ti.com/.../iso1410dwevm


    Regards,
    Koteshwar Rao

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