Frequency accuracy refers to the nominal supply voltage, the nominal load impedance, the reference temperature, and other conditions, the output frequency of the crystal oscillator is stable relative to the nominal maximum frequency shift.
Frequency accuracy of the calibration at the factory calibration reference date when the aging rate of the test results, daily aging rate is positive, negative deviation calibration check, day aging was negative for positive bias calibration, the calibration should continue after run more than 1 hour before testing, the measured frequency is denoted by fx
Frequency Accuracy formula:
A = (fx–fo)/fo ……（1）
The formula:f0—for the nominal frequency
fx—detected after the calibration of the actual frequency value.
Voltage frequency characteristic
Voltage frequency characteristic refers to the other conditions remain unchanged, since the supply voltage is changed within the specified range (for example, ± 5%), the predetermined output frequency is the frequency of the nominal load impedance maximum permissible deviation.
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