Oscillation device

Abstract

An oscillation device capable of highly accurate temperature compensation of an output frequency is provided. The oscillation device includes: first and second oscillator circuits oscillating first and second quartz-crystal resonators with overtones respectively; a frequency difference detecting part finding a value corresponding to a difference value between values corresponding to differences between f1 and f1r and between f2 and f2r, where f1 and f2 are oscillation frequencies of the first and second oscillator circuits, and f1r and f2r are oscillation frequencies of the first and second oscillator circuits at a reference temperature; and a correction value obtaining part which, based on the value corresponding to the difference value and a relation between the value corresponding to the difference value and a frequency correction value of the oscillation frequency f1, obtains the frequency correction value of f1, wherein the output frequency is corrected based on the found frequency correction value.

Description

technical field [0001] The invention relates to an oscillating device which detects the temperature of a placed crystal oscillator and performs temperature compensation of an output frequency based on the temperature detection result. Background technique [0002] TCXO is called a temperature-compensated crystal oscillator. By combining the temperature characteristics of a crystal oscillator and the opposite circuit characteristics, it can obtain better temperature characteristics than a single crystal oscillator in a wide temperature range. In addition, TCXOs not only have excellent temperature characteristics, but also have features such as small size, light weight, and short start-up time, so they are used as reference oscillators for measurement equipment such as various communication equipment, frequency counters, and synthesizers. [0003] TCXO has a temperature compensation circuit including a temperature sensing element. As the temperature compensation circuit, there...

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Problems solved by technology

[0009] However, this method is as described in paragraph 0019. Regarding the desired output frequency f0 and the respective frequencies f1 and f2 of the two crystal oscillators, it is necessary to adjust the crystal oscillator so that it becomes Therefore, not only the manufacturing process of the crystal oscillator becomes complicated, but also there is a problem that a high yield cannot be obtained.

In addition, if Figure 4 As shown, since the clock as the frequency signal from each crystal oscillator is counted for a certain period of time, and the difference (f1-f2) is obtained, the detection time directly affects the detection accuracy, and it is difficult to perform high-precision temperature compensation

In addition, since the fundamental wave and overtone frequency are extracted from one crystal oscillator, the circuit becomes complicated, and the M-order spur of the fundamental wave and fm interfere.

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