Nominal frequency: the nominal value of the center frequency or frequency of the oscillator output.
Frequency accuracy: deviation of oscillator output frequency relative to nominal frequency at room temperature (25 C + + 2 c).
Adjusted Frequency Difference: The maximum allowable frequency deviation of the oscillator output frequency relative to the measured value at 25 C within a specified temperature range.
Load Resonance Frequency (fL): Under specified conditions, a crystal is connected in series or in parallel with a load capacitor, and the combined impedance is one of the two frequencies (resonant) when the resistance is present. When the series load capacitor is connected, the resonant frequency of the load is the lower one of the two frequencies, and when the parallel load capacitor is connected, the higher one of the two frequencies.
Static capacitance: a capacitor connected to a series arm in an equivalent circuit, also called a capacitance, is usually represented by C0.
Working Temperature Range: Temperature Range that ensures that the output frequency of the oscillator and its characteristics meet the requirements.
Frequency Temperature Stability: Maximum allowable frequency offset with or without implied reference temperature operating within a specified temperature range under nominal power supply and load.
Ft = ± (Fmax - Fmin) / (Fmax and Fmin)
ftref = ±m(xù)ax [| (fmax - fref) / fref |, | (fmin - fref) / fref |]
FT: frequency temperature stability (without implicit reference).
Ftref: frequency temperature stability (with implicit reference temperature)
Fmax: the highest frequency measured in the temperature range.
Fmin: the minimum frequency measured in the temperature range.
Fref: specify the frequency of the reference temperature.
Explain
The crystal oscillator with ftref index is more difficult to produce than the crystal with FT index.
oscillatorTherefore, the crystal oscillator with ftref index is sold at a higher price.
Load capacitance: determine the load resonance with the crystal.
frequencyThe effective external capacitance of FL is expressed in CL.
Load capacitance series: 8PF 12PF 15PF 20PF 30PF 50PF 100PF
Excitation level: the characteristic value of power consumed during crystal operation. 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.
Aging rate: the relative change of output frequency within a definite time.
Fundamental frequency: the lowest vibration frequency in vibration mode.
Overtone: the mechanical vibration of crystal vibrations. The ratio of overtone frequency to fundamental frequency is close to integer multiple, but not.
integerTimes, this is the main difference between it and electrical harmonics. The overtone has 3 overtones, 5 overtones, 7 overtones, 9 overtones, etc.
