DS26F31MQML: state of the output after crash

Hello Slava,

When there is overstress failure, the most typical electrical signature is a low impedance from the stressed IO to GND.  However, the unpredictable nature of IC failure mechanisms make it difficult to ensure that the IO would fail in this manner under any potential stress condition.  And, it is possible for a primary failure to result in other behaviors such as heating of the die that could then induce further secondary failures in similarly unpredictable ways.

Regards,
Max

Kirill,

Yes, you are correct - we can advise on most likely failure modes but there isn't a way to ensure them in all cases.  The best solution is to avoid over-stress failures by keeping operation within the limits defined by the device datasheet.  For IOs interfacing to external ports, a common approach is to use a TVS diode in order to clamp any voltage excursions to within an allowed range.  Depending on the expected stress, other protection schemes could be used as well.

Here is some info on how to choose a TVS diode for interface devices in order to protect from transient stresses like ESD:

https://e2e.ti.com/blogs_/b/industrial_strength/archive/2017/11/13/how-to-choose-a-tvs-diode-for-rs-232-rs-485-and-can-based-on-voltage-ratings

For protecting against DC stresses such as short-circuit conditions (e.g., due to miswirings), you could reference this reference design:

http://www.ti.com/lit/ug/tiduer9/tiduer9.pdf

Regards,
Max