I'm using a CMOS chip (CD4098B) for a small circuit I'm making which will have quite long wires (2m or so) going of from the inputs through a switch and back to Vcc. The pins are pulled down with a 100K resistor.
Now, when I just touch an input pin with a wire (or my finger) it goes high despite the pull-down resistor. I really want to avoid this to make the circuit more reliable and I would prefer not to use shielded wires.
I tried to put a 0.1µF cap in parallel with the pull-down resistor and it seems to work but I don't know why so I thought I'd ask anyway.
My guess is that it has something to do with the capacitance in long wires?
Now, when I just touch an input pin with a wire (or my finger) it goes high despite the pull-down resistor. I really want to avoid this to make the circuit more reliable and I would prefer not to use shielded wires.
I tried to put a 0.1µF cap in parallel with the pull-down resistor and it seems to work but I don't know why so I thought I'd ask anyway.
My guess is that it has something to do with the capacitance in long wires?