I am looking for a way to generate 10 to 20MHz TTL-compatible clock signal. I used something like microchip unit to produce clock signal before in school but I didn't use any other way to generate clock pulses. Someone suggests to use 555 timer but I one of the handbook I have told that 555 timer won't support clock frequency as high as 20MHz. Is that true? I need a pretty stable clock signal which will be run for more than 60 hours continuously once it is on. Any other suggestions?
Both modules mentioned have tolerances of 50 ppm and operate at 5V.
It's not to be confused with regular 2 pin crystal like this below. Those are part of the circuitry of external clocks for MCUs, for example.