what is crystal oscillator?

Question

how is it work

Answer 1

An oscillator that has a (usually quartz) crystal in its feedback loop. The crystal has a natural frequency of mechanical vibration, and since it is piezoelectric (deformations produce a voltage and applied voltage produces a deformation) it can resonate in an electric circuit, showing a peak response at its natural frequency or an overtone of that frequency. Quartz oscillators are usually much more accurate and less likely to drift with temperature than simple L-C based resonant circuits. See the ref. for details.