In one running product (DC/DC converter) we have used the part ADUM6404A, which has now failed in operation in the 2nd unit in the field.
The failure behaviur is the following:
If the 5V input to the internal DC/DC converter (5VS_D) gets interrupted in operation for a short time (< 2 seconds), and then comes back, the output of the internal DC/DC converter does not start up anymore.
Later and in general, if the 5V input then gets interrupted for a longer time (for example > 5s), the internal DC/DC converter does start up again.
By replacing the ADUM6404A the failure disappears again.
I have the two failed chips available here for inspection, our customer is quite concerned as this is a critical phase in the project.
- Is this a known failure mode of these kind of devices?
- May the issue be related to a specific production lot only? The parts have been sourced from distribution.
- Is such a behaviour related to ageing?
Thanks for your help on this