Main Technical Indicators of Epson Crystal Vibrator Crystal Resonator
Release date:2018-12-21 Author:Guan Shuo Click:
Main Technical Indicators of Crystal Resonators
Crystal resonator is a quartz crystal resonator made of quartz material, commonly known as crystal oscillator. The famous brand is Epson crystal oscillator. It has the characteristics of frequency generation, stability and good anti-interference performance, and is widely used in various electronic products.
Nominal frequency: The nominal value of the central frequency or frequency of the oscillator output.
Frequency Accuracy: The deviation of the output frequency of the oscillator relative to the nominal frequency at room temperature (25 +2).
Adjustment of frequency difference: The maximum allowable frequency deviation of the oscillator output frequency relative to the measured value at 25 C in the specified temperature range.
Load Resonance Frequency (fL): Under specified conditions, a crystal is connected in series or in parallel with a load capacitor, and its combined impedance is one of the two frequencies at which resistivity (resonance) occurs. 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.
Electrostatic capacitance: The capacitance parallel to the series arm in the equivalent circuit, also known as parallel capacitance, is usually expressed in C0.
Working temperature range: It can ensure that the output frequency of the oscillator and its various characteristics meet the temperature range of the index.
Frequency Temperature Stability: Under nominal power supply and load, the maximum allowable frequency deviation with implicit reference temperature or implicit reference temperature is not included in the specified temperature range.
Ftref=+MAX[|(fmax-fref)/fref |, |(fmin-fref)/fref |]
Ft: Frequency temperature stability (without implied reference)
Ftref: frequency temperature stability (with implied reference temperature)
Fmax: the highest frequency measured in a specified temperature range
Fmin: the lowest frequency measured in a specified temperature range
Fref: Frequency measured at specified reference temperature
Crystal oscillator with ftref index is more difficult to produce than crystal oscillator with ft index, so the price of crystal oscillator with ftref index is higher.
Load Capacitance: The effective external capacitance that determines the resonant frequency of the load FL together with the crystal, expressed in CL.
Load Capacitor Series: 8PF 12PF 15PF 20PF 30PF 50PF 100PF
Excitation level: The characteristic value of the 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.
Aging rate: Relative change of output frequency in a given time.
Fundamental Frequency: Vibration frequency at the lowest order of vibration mode.
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.