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SN65HVD11-HT: Frequent Device Failure

Part Number: SN65HVD11-HT

We have a fairly significant failure rate of these devices. I am looking for some ideas on why?

The chips are used in down-hole systems. Oil drilling equipment is subject to very harsh environment. The equipment is subject to rough handling, sees very high vibration and sometimes shock, as well as temperature extremes. Some places, the equipment might start the day at -20C and then go to 120C during operation. Other places, the temperature might rise to 170C. On the flip-side, we have seen failures to a lesser degree during production before the equipment goes to the field.

Most of the circuit boards have protection against accidentally applying 36V across the A/B lines. The chip itself is supposed to be ESD protected.

The most typical failure/symptom is the RX stops working.

So I have some questions, and maybe you have additional questions/ideas:

  1. Does this chip require power sequencing? For example, can the A/B lines be active without the chip powered up?
  2. Any chance to cause a latchup problem?
  3. How important are series resistors on the A/B lines? We don't have any.
  4. Should additional electrically fast transient protection be applied to A/B lines?
  5. How sensitive are these parts to high vibration?
  6. Is it possible that we are inducing infant mortality during production? For example, improper handling?
  7. Our production model screens all boards in HASS. They are exposed to cycling temperature and vibration. Does this remove life from this part?

In addition to these, can you make any other comments/recommendations?

best regards,


  • gene,

    I suggest you contact TI quality team through your vendor for submitting failure analysis for the failure parts. The FA can reveal what part is damaged in the IC. With this information, we might be able to narrow down the failure cause like the ESD or vibration. I try my best to answer your questions. Hopefully some of information can be helpful to you.

    1. The A/B lines should be in impedance mode in power off mode.

    2. The latchup test per JESD78 is tested in manufacture.

    3. The series resistors can help limit the transient current in some ESD events. The effect could vary case by case.

    4. It's better to know the characteristics of the ESD events before we can improve the design.

    5. I haven't found any data about this yet.

    6. Most of time the devices would not be partially damage. The abnormality can be found by checking the functionality and IO characteristics.

    7. I think the answer is yes, since the part has gone through the stress mimicking the life time usage.