Test circuit and test device for quartz resonator

Abstract

The invention discloses a test circuit and a test device for a quartz resonator. The test circuit comprises a first signal end, a second signal end, a frequency adjusting module, a frequency broadening network module, a voltage-controlled or electric-modulation network module and an inhibition network module, wherein the first signal end and the second signal end can be connected with a quartz resonator parameter test clamp; and a to-be-measured quartz resonator is connected between the frequency adjusting module and the frequency broadening network module. According to the test circuit and the test device, the actual elements in an oscillation circuit of a crystal oscillator are connected in series in the branch of the quartz resonator, and the purpose of truly simulating the load condition of the quartz resonator is achieved, so that the load types in the commercial quartz resonator test devices are expanded, and the accuracy of judging whether the quartz resonator is applicable or not can be improved; in addition, the circuit of the invention can enable part of elements to be invalid by means of short connection and other means, so that different real environments can be simulated, and the test circuit and the test device can be wider in applicability; and finally, the device is simple, convenient and easy to operate, high in accuracy and relatively high in practicability.

Description

technical field [0001] The invention relates to the technical field of crystal oscillators. More specifically, it relates to a test circuit and test device for a quartz resonator. Background technique [0002] The quartz resonator is the core component of the crystal oscillator, and its performance determines the performance of the entire oscillator to a large extent. The capacitive three-point oscillator circuit commonly used in crystal oscillators such as figure 1 As shown, the resonant tank consists of a quartz resonator and two feedback capacitors. The stable operation of the oscillator circuit requires the quartz resonator to have good resonance characteristics, that is, the resonant frequency of the quartz resonator should be near the operating frequency of the oscillator under equivalent load conditions, and the spurious frequency should be as small as possible, and the amplitude at the spurious frequency should be as low as possible. In order to achieve this purpo...

AI Technical Summary

Problems solved by technology

Therefore, there is a large gap between the test conditions of the quartz resonator and the actual use conditions, and accurate test results cannot be obtained

When the parasitic of the quartz resonator is small and far away from the main resonant frequency, it is difficult to find it with commercial test equipment. Sometimes in order to confirm the parasitic phenomenon, it may be necessary to repeatedly fine-tune the load capacitance, which takes a long time and is inefficient, resulting in the influence of the parasitic frequency. Appropriate evaluation cannot eliminate abnormal phenomena such as frequency hopping caused by parasitic in time, which seriously affects the product qualification rate and reliability

Images