Time keeping method for controlling voltage-controlled crystal oscillator based on temperature variation difference

Abstract

The invention provides a time keeping method for controlling a voltage-controlled crystal oscillator based on a temperature change difference, and the method comprises the steps: collecting the ambient temperature around the crystal oscillator when the crystal oscillator normally operates to track a reference source, and averaging the ambient temperature through accumulation to generate a temperature reference; subtracting the reference temperature from the ambient temperature around the crystal oscillator after the reference source is disconnected, and calculating the temperature deviation around the crystal oscillator; and converting the temperature deviation into the voltage-controlled voltage of the crystal oscillator, and eliminating the frequency deviation of the crystal oscillator at the holding moment. According to the invention, the crystal oscillator is controlled according to the relationship between the temperature deviation and the control quantity of the voltage-controlled crystal oscillator, so that the short-term stability of the crystal oscillator is not obviously reduced, and the retention capability of the output time signal of the crystal oscillator is improved.

Description

technical field [0001] The invention relates to a high-precision time keeping method. Background technique [0002] For timing equipment, time servers, and time synchronization equipment that use crystal oscillators as frequency sources, in the event of satellite abnormalities and data link interruptions, the equipment is still required to continuously output time signals, and the performance of the time signals cannot be significantly reduced. The crystal oscillator in the device is required to have a high time holding capacity. Especially in the era of 5G and the upcoming 6G, high-precision time synchronization has become an inevitable trend, and the time signals between base stations are required to have high synchronization accuracy and good reliability, especially when the reference time source fails. Time keeping ability. At the same time, for a large number of base station needs, it has become a must to use the crystal oscillator as the frequency source and time sou...

AI Technical Summary

Problems solved by technology

That is to say, the ability to weaken the influence of ambient temperature on the crystal oscillator and the short-term stability of the crystal oscillator is still very good.

[0004] At present, although the market controls the crystal oscillator according to the temperature change to improve its time holding ability, its time holding ability still exceeds 1μs / 1d

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