A crystal oscillator is basically a tuned oscillator. It uses a piezoelectric crystal as a resonant tank circuits. It is an electronic oscillator circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a precise frequency. The crystal provides a high degree of frequency stability and accuracy so it is used whenever, great stability is required.
symbol of crystal oscillator
The most commonly used crystal is the quartz crystal because it is cheap and gladly available in nature and its properties lies in between the Rochelle salts and tourmaline. The crystal oscillator has high Q as compared to tank circuit, which makes the oscillation frequency very stable. By the capacitor CS and CM the series frequency fS and parallel frequency fP can be changed. The value of the components of L, CS, R and Cm are such that the two frequencies, fS and fP differ by a very small amount, which gives great frequency stability of a crystal oscillators.