1. Nominal frequency

Refers to the frequency value of the vibration circuit output under normal matching vibration circuit. Indicate as MHz or KHz.

2. Adjust frequency difference

The promised error of the target frequency at a certain temperature (25 ℃) is expressed as parts per million (ppm).

3. Temperature frequency difference

The promised error of the target frequency within the operating temperature range.

4. Scale of homework temperature

The temperature scale of quartz crystal components operating within regular errors.

5. Storage temperature scale

The temperature scale at which a crystal maintains its standard characteristics in a non operational state.

6. Load capacitance

① Once any external capacitor is connected in series with a quartz crystal component, it becomes a determining factor in its resonant frequency.

When the load capacitance changes, the frequency will also change accordingly. Therefore, when used in circuits, the frequency is often fine tuned to the desired value by regulating the load capacitance.

② The load capacitor series includes: 8pf, 10pf, 15pf, 20pf, 30pf, 50pf, and 100pf.

③ CL=Cg * Cd/(Cg+Cd)+CsCg and Cd are the capacitance values connected to the two pins of the crystal. Cs is the stray capacitance value of the line, generally ranging from 2 to 6pf.

7. Static capacitance

The main source is the capacitance formed by the quartz chip as the dielectric material and two electrodes, with a small portion coming from the capacitance between the conductive material connecting the quartz chip and the connecting wire, as well as the capacitance of the packaging shell.

8. Cutting method

According to different application fields and operating temperature requirements, there have been many different types of quartz cutting viewpoints. For example, different cutting plates such as AT -, BT -, CT -, DT -, NT, GT, etc. Plates with different cutting directions have different elastic constant tensors, piezoelectric constant tensors, and dielectric constant tensors. The temperature frequency characteristics are related to the cutting angle. Each quartz crystal has a crystal axis, and the crystal is cut along a viewpoint perpendicular to the crystal axis according to its vibration form.

9. Vibration form

The quartz chip exhibits various vibration forms due to different quartz cutting viewpoints and electric field effects of different electrode shapes. The frequently occurring vibration forms can be divided into tortuous form, stretching form, surface shear form, and thickness shear vibration form.

10. Equivalent resistance

Equivalent resistance (ESR, Rr, R1), also known as resonant resistance. Under regular conditions, the resistance of a quartz crystal resonator without a series load capacitor at the resonant frequency.

11. Encourage power level

The characteristic value of power consumption during crystal operation. Generally speaking, the frequency change of AT cut crystals is positive as the encouraging level increases. Excessive encouragement level can cause nonlinear effects, leading to possible parasitic vibrations, severe thermal frequency drift, overstress frequency drift, and sudden resistance changes. When the encouragement level is too low, it will cause difficulty in overcoming the starting resistance, poor operation, and instability of the target.

12. Encourage level correlation

Also known as encouragement level dependence, it refers to the effect of the resonant resistance of crystal components changing with the encouragement level condition. When the excitation level applied to the crystal element is changed, its resonant resistance also changes accordingly. This change generally follows a certain pattern and can be expressed by the ratio of the two resistances corresponding to the two excitation levels. Its expression is: DLD=Rr1/Rr2 (Rr1- is the resistance of the lower excitation level, and Rr2- is the resistance of the higher excitation level).

13. Insulation resistance

The resistance between the insulation terminals or between the terminals and the casing.

14. Fundamental frequency

The lowest order vibration frequency in the form of vibration.

15. Overtones

Mechanical harmonics of crystal vibration. The ratio of overtone frequency to fundamental frequency is close to an integer multiple but not an integer multiple, which is its main difference from electrical harmonics. There are 3 overtones, 5 overtones, 7 overtones, 9 overtones, etc. in overtone vibration.

16. Equivalent circuit

The vibration of a quartz crystal resonator is essentially a mechanical vibration that can be measured by a two terminal network with electronic conversion properties. This circuit includes L1, C1, and a capacitance of C0 as an insulator of a quartz crystal, which is incorporated into the circuit. The impedance R1 related to elastic vibration is the resonant impedance of the quartz crystal resonator at the resonant frequency.

17. Negative impedance

The impedance characteristic value of the vibrating circuit at the vibration frequency when viewed from the two terminals of the quartz crystal resonator towards the vibrating circuit. Negative impedance is not a product parameter of quartz oscillators, but an important characteristic parameter of vibration circuits. To improve the starting conditions in vibration circuits, it is necessary to improve the negative impedance in the vibration circuit. Without sufficient negative impedance errors in the circuit, it is difficult to start vibration. The value of negative impedance in a vibration circuit should reach 5-10 times the resonant impedance.

18. Annual aging rate

The relative change in crystal operation frequency allowed over time under regular conditions, measured in years. The maximum frequency change occurs in the first month after the production of crystal frequency components, after which the frequency decreases over time. There are many reasons that can cause this aging, such as sealing characteristics and integrity, manufacturing processes, data types, operating temperatures, and frequencies.