We have a customer problem where the EN pin on the TPS54240 could be biased > 5V, but at very low current going into the EN pin. This problem is limited to the first run of boards and the design will be corrected ASAP.
In the mean time, they need to understand if there is a failure-in-time issue with this bug.
The abs,max for the device is obviously 5V, but it appears that there are some internal linear regulator, etc... that is biasing the EN threshold comparator and the hysteresis current source.
Would some (uA's) of current going into the EN pin presumably through some clamping diodes, etc... cause a major upset?
Not really interested in the precision UVLO adjustment, just using for EN ON/OFF.
Any details you can provide regarding the input stage of this device would be most helpful.
Thanks!
-Steve
