Basically, I'm trying to generate a short pulse when the user pushes a button using a CMOS gate and a rudimentary RC charging circuit. It all simulates fine in Multisim, but I'm concerned what will happen when I run this for real (still waiting for parts in the mail). Here's the diagram: [PLAIN]http://img819.imageshack.us/img819/876/timing.png [Broken] The IC will be a CD4075 triple input OR-gate, and it will run off a 5V USB supply. The other inputs will be connected to identical circuits, so at the end, you get a pulse when any of the buttons are pushed. From what I can gather, Multisim just assumes "if <2.5V, go low, if >2.5V, go high", but I'm unfamiliar with how real CMOS gates handle metastability, and the datasheet is no help (it just says "1.5V maximum low, 3.5V minimum high"). The timing does not have to be that accurate (a pulse length anywhere between 25ms to 100ms should be fine), but I'd still like to know at what point on the capacitor charging curve to expect the output to go back low so I can make calculations (I made them for 2.5V initially). What I'm afraid to hear is that, as the input voltage reaches the metastable point, the output may go low or high randomly. That is NOT acceptable for my purposes, so I need to know whether or not that will happen. One more thing: as the capacitor discharges, will the -5V on the input harm the gate? I can put in a schottky diode if it will, but I have very little room on my circuit board, so I want to avoid all unneccesary components.