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SN65LBC184: Using SN65LBC184D to replace SN75LBC184D caused device burning

Part Number: SN65LBC184

Hi There,

Our orginal design uses SN75LBC184D, but the 75 version is now in shortage on market, to fullfill the production demand we bought some SN65LBC184D to use as replacement, as we checked the date sheet 65 verision is a higher level than 75 on function.

But now we encountered some serious problem, when using the SN65LBC184D some of them cannot receive the signal totally or keep receiving  wrong signal; while some others even burned themselves. We kept the circuit environment the same.

May I know why and any method to solve it? Thanks a lot!!

  • Hi Meg,

    The SN65* and SN75* versions of this device both use the same design, they are just tested over different temperature ranges. Have you used SN75* devices recently, and if so have you observed any similar issues? I'm curious if anything has changed about the application environment that may be stressing these devices.

    Can you also please provide a photo of the SN65LBC184D units and their packaging (showing the lot trace code)? I'd like to make sure these are actual TI devices. (Although it isn't very common, sometimes popular devices like this are counterfeited and provided to unauthorized distributors for resale.)

    Max
  •   Hi Max,

    We're confused too, per new feedback from production factory,  they have problem with 75 version too, but not so often and bad like 65.

    Anyway, attached the pics you asked, but unluckily the supplier broken the trace already, not sure if you can find anything out from them. Thank you!!

  • Hi Meg,

    Thanks for providing these. We checked the lot information and could confirm that these are most likely genuine TI parts.

    Have there been any changes in your design, assembly process, test procedure, or operating conditions that might correlate to these failures? Can you think of any electrical stresses that these devices may endure (for example, a short-circuit from the RS-485 signal lines to a power rail, an overshoot on VCC at ramp-up, etc.)?

    Are the SN75 parts showing the same type of issue, or is it a separate issue than what you have observed with the SN65 parts?

    Regards,
    Max