I wanted to use a 555 timer in astable mode to generate a 5V signal to flash an LED on and off. This works fine when the pulse length of the LED is in seconds or milliseconds. But this got me thinking about pulse generators more generally. Disregarding the LED for a moment, I would like to generate a much faster signal with width 300ns. I do not believe that the 555 timers are fast enough to do this. Does anyone have any suggestions on possible high speed timers? Thank you.