Quartz crystal vibrator is composed of a very high quality quartz crystal oscillator (ie, resonator and vibration circuit composition. Crystal quality, cutting orientation, crystal oscillator structure and circuit, etc., together with the resolution of the vibrator function. World Electrotechnical Commission IEC) classifies quartz crystal vibrators into four categories: normal crystal vibration (TCXO), voltage controlled crystal vibrator (VCXO), temperature compensated crystal vibration (TCXO), thermostatic controlled crystal vibration (OCXO). (DCXO), and so on.

Usually the crystal oscillator (SPXO) can occur 10 ^ (-5) ~ 10 ^ (-4) order of the frequency accuracy, the standard frequency 1-100MHZ, frequency stability is ± 100ppm. SPXO does not use any temperature frequency compensation method, offer low, usually used as a microprocessor clock equipment. Package scale scale from 21 × 14 ×

6mm and 5 × 3.2 × 1.5mm.
       The accuracy of the voltage controlled crystal oscillator (VCXO) is 10 ^ (-6) ~ 10 ^ (-5), the frequency scale is 1 ~ 30MHz. The frequency stability of the low tolerance vibrator is ± 50ppm. Usually used for phase-locked loops.
Package size 14 × 10 × 3mm.
       The temperature-compensated crystal vibrator (TCXO) uses temperature sensitive equipment for temperature and frequency compensation. The frequency accuracy reaches the order of 10 ^ (-7) ~ 10 ^ (-6), the frequency scale is 1-60MHz, the frequency stability is ± 1 ~ ± 2.5ppm, package size from 30 × 30 × 15mm to 11.4 × 9.6 × 3.9mm. Usually used for hand-held phones, cell phones, two-way wireless communications equipment.
       The thermostatically controlled crystal vibrator (OCXO) places the crystal and vibrating circuit in a thermostat to eliminate the effect of ambient temperature changes on frequency. OCXO frequency accuracy is 10 ^ (-10) to 10 ^ (-8) order of magnitude, for some special use and even higher. The frequency stability is highest in the four types of vibrators.