Crystal vibration often faces some problems in the process of use, which affects the use of crystal vibration, what are the common problems that need our attention? Below, Xiaobian to summarize for you.



First, the crystal frequency is abnormal

The cause of this problem may be that when the center frequency of the circuit is positively biased, the CL is small. The value of Cd and Cg can be solved by increasing the external capacitance of the crystal oscillator.

Another reason is that when the center frequency of the circuit is negative, CL is large. The value of Cd and Cg can be solved by reducing the external capacitance of the crystal oscillator.



Second, crystal vibration excessive heat and stop vibration

If the influence of the working environment temperature is excluded, the excitation level may be too large. To solve the problem that the excitation level DL can be lowered, Rd can be added to adjust DL.



Third, the crystal oscillator slowly stop the vibration, after hand contact or use the electric iron to heat the crystal oscillator pin to work again.

This problem is caused by the fact that the negative impedance value in the oscillating circuit is too small. It is usually required to adjust the values of the external capacitors Cd and Cg of the crystal oscillator to achieve the loop gain of the oscillator circuit.



Fourth, crystal vibration virtual welding or pin, pad do not eat tin

This is usually caused by the oxidation of the pin, or it may be caused by the loss of the pin coating. The storage environment of the crystal oscillator is required to meet the standard, and it is stored at normal temperature and normal humidity to avoid moisture. In addition, it may also be related to the manufacturer's manufacturing process, be sure to choose quality assurance.