1. an amplifier overall loop gain greater than 1
2. a feedback circuit providing positive feedback
So the question is can a logic gate be used as an amp? Let's take a quick look at a couple of gate circuits.
|I made this one and it oscillates with 1-1/2 volt to 4-1/2 volt. It locks to the crystal frequency. I can adjust the duty cycle and shape the wave a little. It seems the pulse train is locked to the crystal frequency. The duty cycles swings from 37/63 to 48/52 but the frequency counter holds steady?|