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Professional terminology on Epson crystal oscillator

Release date:2018-12-24 Author:Guan Shuo Click:

Professional terminology on Epson crystal oscillator

1. Nominal Frequency: Crystal oscillator is a kind of frequency component. Each crystal oscillator has its own frequency. Frequency is usually marked on the product shell, while imported crystal brand will have logo logo or letters instead.

2. Working Frequency: Frequency produced by crystal and working circuit.

3. Adjustment of frequency difference: Under specified conditions, the deviation of working frequency relative to nominal frequency is allowed at reference temperature (25 +2 C).

4. Temperature Frequency Difference: Under specified conditions, the allowable deviation of working frequency in the working temperature range relative to the reference temperature (25 +2 C).

5. Electrostatic capacitance: The capacitance parallel to the series arm in the equivalent circuit, also known as parallel capacitance, is usually expressed in C0.

6. Aging rate: Under specified conditions, the relative variation of crystal working frequency with time is allowed. When measured in terms of years, it is called the aging rate.

7. Load Capacitance: The effective external capacitance that determines the resonant frequency of the load together with the crystal, usually expressed in CL. Load capacitor series: 8PF, 12PF, 15PF, 20PF, 30PF, 50PF, 100PF. Recommended values should be selected whenever possible: 10PF, 20PF, 30PF, 50PF and 100PF. The load capacitance of 32.768K crystal oscillator is 12.5PF, 6PF, 9PF and so on.

8. Load Resonance Frequency (fL): Under specified conditions, a crystal is connected in series or in parallel with a load capacitor, and its combined impedance appears as one of the two frequencies of resistivity. When series load capacitors are connected, the resonant frequency of load is the lower of the two frequencies, and when parallel load capacitors are connected, the higher of the two frequencies.


Epson crystal oscillator


9. Load resonant resistance: the equivalent resistance at the load resonant frequency. Represented by RL. RL=R1(1+C0/CL)2

10. Dynamic Resistance: Equivalent Resistance at Series Resonance Frequency. Expressed in R1.

11. Fundamental frequency: The lowest order of vibration frequency in the vibration mode.

12. Excitation level: the characteristic value of power consumed in crystal operation. The optional excitation levels are: 2 mW, 1 mW, 0.5 mW, 0.2 mW, 0.1 mW, 50 uW, 20 uW, 10 uW, 1 uW, 0.1 uW, etc.

13. Overtone: Mechanical harmonics of crystal vibration. The ratio of pan-audio frequency to fundamental frequency is close to integer multiple but not integer multiple, which is the main difference between pan-audio frequency and electrical harmonics. Overtone vibration has 3 overtones, 5 overtones, 7 overtones, 9 overtones and so on.

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