I'm looking for a device to switch video signals; a video switch. I want to use a dual/triple switch for two purposes, first to switch between two video signals, and secondly to switch the signal between open and +3.3V (which drives the pixel on the frame high.) (The third channel may be used to switch between on and off for the pixel.) It's for an on screen display application.
However, most chips I've seen have an on resistance of nearly 60-80 ohms. This is way too much surely for video which is terminated with 75 ohms? If I'm switching with 75 ohms in series with the required 75 ohm termination, I've effectively created a voltage divider and halved the video signal. It might work, but the video would probably lose considerable quality; at worst, I'd probably lose sync.
As an additional question, related to this one, would there be any bandwidth issues with video switches? I'm using composite (CVBS) NTSC or PAL colour video.