ADC Pin Fed 4.2V

[callum_taylor]

Hi,

We have a design error of not having not updated a voltage divider circuit when we increased the high voltage line in an earlier iteration. The range of the voltage divider output has now gone from 0V - 3.1V, to 0V - 4.2V. This means under some circumstances when the high voltage is turned on, the nRF54L15's ADC pin will be seeing up to 4.2V

Is it likely that 4.2V on the ADC pin can damage the nRF54? Is there something we can do to disable the pin on a firmware level and protect the nRF54? We have just received 50 conformal coated PCBs, so if there is an option we can disable the ADC line, protect the nRF54, and not have to rework all the PCBs, that would be preferable.

Thanks,

Callum

[ketiljo]

Maximum voltage on any pin is VDD + 0.3 V. Anything above this will cause damage to the pin. It doesn't matter of the pin is disconnected or not.