I'm trying to calculate the value of a resistor to protect a digital input on a microcontroller (10Ω and 1kΩ in the image below):
The microcontroller datasheet (PIC16F1718 Datasheet) doesn't specify an input resistance (shown as 20 MΩ in the drawing,) so I'm unable to determine how high a resistor value I can use without interfering with logic levels.
The datasheet does list the max "Input leakage current." I understand that to be the current into the input pin when the input voltage is at maximum. Is that correct?
Since I know the input leakage current and the max input voltage, can I use Ohm's law to then calculate the DC resistance of the input pin? When I do the calculation I get 5MΩ which seems reasonable.