I'm designing a very basic circuit for testing a switch sequence. I'm using a CMOS decoder CD4028B (link to datasheet) and XOR gate (CD74HC86E - link to datasheet). Reading the switch sequence is crucial and therefore I've been thinking whether I should add pull-down resistors to all inputs of the decoder and XOR gate to prevent pin-floating and false readings? I went through the datasheet and there was no recommendation whether pull-downs should be added to prevent pin-floating. Do these logic gates usually provide internal pull-down resistors or is it necessary to add them yourself? What values are recommended? I want to draw as little current as possible. I'm sorry if this is a really basic question. We made quite a few circuits with logic gates in college but never talked about the pin-floating and current draw aspect of these circuits.
Inputs of decoder are wired to the switch that is being tested, outputs of decoder are then wired to XOR gate inputs and XOR gate outputs are then wired to BJTs to drive LEDs.
Any help would be greatly appreciated. :)