I'm trying to do some kind of keyboard device which has like 12-15 digital inputs and outputs to a serial USB port. Because other similar circuits I've seen I know I need a microcontroller and some capacitors. The problem is, my device has to be very small and I can't put capacitors and a big IC all over the place. I guess the best option would be some Analog/digital IC with everything integrated inside, but I don't know if this is even possible. Ideally I would like just an IC of that kind, the smallest possible one, and just circuits for the rest (and the buttons of course). SMD capacitors are also an option but I would prefere everything inside de IC.
Is this even possible? If someone can make some clarifications I would be happy