How to control the temperature has become the number one problem in the use of quartz crystal oscillator

In today's rapidly changing electronic products, cost is undoubtedly an important factor to be considered by manufacturers and quartz crystal oscillator manufacturers. Cost is also considered in the application program. Therefore, engineers design the circuit because the price of PIP through-hole passive resonator of active quartz crystal oscillator (commonly known as clock oscillator) is 5 ~ 10 times that of ordinary passive resonator, Therefore, more passive crystals are used in the circuit. Only in some high-end products, such as industrial control products and high-speed communication products, active crystal vibration is preferred, so the above common problems are.
The reason is that the use effect of passive crystal oscillator not only depends on the index of crystal oscillator itself, but also has great correlation with the design of oscillation circuit, and the matching is often not ideal. Active crystal oscillator is a direct crystal and clock vibration integrated circuit "bound" package. After debugging, it will be provided to users to avoid the problem of circuit frequency drift caused by improper matching of customer crystal load. How can surfactant crystal vibration (bell vibration) avoid the above adverse phenomena.
Quartz crystal oscillator is usually called quartz crystal. It is composed of silica. It has "piezoelectric effect" and very high quality factor. It has been applied to oscillation circuit. The frequency stability can reach 10-6 ~ 10-8 or even higher. However, its frequency accuracy is affected by two inherent characteristics of quartz crystal: frequency traction and temperature drift. The frequency traction quantity is a physical quantity that describes the change of crystal frequency accuracy with the change of load capacitance. The unit is ppm / PF. The physical quantity of accuracy varying with temperature is the inherent characteristic of quartz crystal oscillator. Its frequency temperature curve and the cutting mode of quartz chip are related to the cutting angle. From the user's point of view, the user cannot change the chip angle, but it is easy to change. The variable oscillation reflux load is also the reason. When using the quartz crystal oscillator, the customer is prone to frequency drift caused by the configuration due to the load.
The reason for the high precision and good stability of quartz crystal oscillator is that the clock oscillator adopts a professional oscillation chip. The clock oscillator is not adjusted. Before packaging, the crystal frequency is fine tuned by spraying silver on the wafer or etching electrodes to change the thickness of the wafer. Therefore, the oscillation circuit can output the desired target frequency, avoid the frequency drift caused by load mismatch and improve the accuracy of the oscillation circuit.
Another important property of quartz crystal oscillator is temperature drift. All frequency devices are made of quartz crystal material, which has a certain temperature drift. Temperature drift is an important factor affecting the frequency accuracy of quartz crystal resonator and oscillator. Temperature compensated crystal oscillator (TCXO) and constant temperature crystal oscillator (OCXO) are the corresponding compensation for crystal frequency and temperature characteristics. The precision TCXO is less than + 2.5ppm, OCXO is less than + 10ppb (1ppb = 10-3ppm), or even higher. Temperature filling compensation is an important means to compensate the temperature drift of quartz crystal. However, there are few temperature compensated bell vibrations of kHz level in the market.

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Keyword：Quartz crystal oscillator   clock oscillator   passive resonator   active crystal   silica   piezoelectric effect   temperature compensated crystal oscillator   thermostatic crystal oscillator   Commax-Tech Electronic