To Whom it May Concern,
I have a few questions about the ADuM7442S.
1. What are the under voltage lockout specifications for the ADuM7442S if any? I don’t think that there’s anything in the datasheet, just recommended operating conditions.
2. The ADuM7442S datasheet shows figure 2 as the “safety-limiting current” for the package as a thermal consideration. I am wondering what kind of limits are on the current for a single input pin when the ESD diode is forward-biased. I can’t imagine that at 50C it’s >250mA for a single pin, it can’t be limited by just the package heating. (If this question makes sense to you, then please feel free to answer.)
I'm looking into the UVLO question and will update this thread when I have more info.
Regarding the safety limiting data - this is meant to provide guidance on fault tolerance. The total power dissipated during a fault condition should be below what's indicated in the curve in order to maintain integrity of the isolation barrier. It's not specific to a particular I/O pin, and is not meant as a normal operating condition. The ESD diodes are not specified to carry current since they shouldn't be biased under normal operation, but we typically recommend a 1 mA limit if there are short transient conditions where they may become forward biased.
There is a UVLO circuit, but the performance is unspecified unfortunately.