Referencing this TI inverter as an example part: http://www.ti.com/lit/ds/symlink/sn74ac14.pdf
Specifically, the table at the bottom of page 2 (I would put a picture but I do not know where to upload it). It lists the max Vcc as 6V. It also says the voltage input range is -0.5V to Vcc+0.5V. There is also a note 1 which says "The input and output voltage ratings may be exceeded if the input and output current ratings are observed."
I want to use a Vcc of 3.3V, but I have one input that would be 5V. TI has other inverters that allow 5V inputs with 3.3V Vcc, but their input leakage current is too high for my other inputs. Therefore I am interested in exploring this note.
What does it mean when it says "if the input current rating is observed"? Would this be the input clamp current, Iik (+/- 20 mA)? If so, does that mean I need to put a series resistor in front of the input, so that e.g. 5V – 3.3V = 1.7V (EDIT: and subtract diode drop 0.5V = 1.2V) dropped over the series resistor induces Iik < 20 mA? Should I be concerned about this series resistor being too large, such that the induced current would be less than the input current Ii = +/- 1 uA max?
This question is slightly related to another question on this stackexchange ( Why is it important not to exceed Vcc at the input to a logic gate? ), where one answer off-handedly mentions using resistors to limit input currents, but I would like more detail using a concrete example, especially since this datasheet implies that it's possible to do safely.