I'm planning to use a MKL17Z256Vxx4 MCU in a extremely low power project. One of the GPIO pins is connected to a switch (which is sometimes on for days and sometimes off for days). Now I'm trying to figure out if I should use an external weaker pull-down or pull-up resistor. One of the things I cannot find is the digital input impedance (only of ADC).
What is the digital input impedance when no internal pull up or down is configured?
Other advise on how to connect a switch in the most power efficient way is welcome.