Double-resonator anti-vibration crystal oscillator

Abstract

The invention provides a double-resonator anti-oscillation crystal oscillator, which comprises an exposed chip, a base and two crystal resonators, and is characterized in that the exposed chip is bonded in a cavity of the base, and a bonding pad of the exposed chip is electrically connected with each port in the base; and the two crystal resonators are symmetrically and reversely connected to the base and are connected to the exposed chip in parallel. The invention provides a double-resonator anti-vibration crystal oscillator which is used for solving the problems that in the prior art, the vibration reduction effect is poor, the structural design difficulty is increased, the size is larger than that of a common crystal oscillator, and due to the fact that a vibration reduction pad is compressed and relaxed to drive the crystal oscillator to move, the crystal oscillator has certain displacement in the vibration environment.

Description

Technical Field

[0001] The present invention relates to the technical field of oscillators, and in particular to a dual-resonator anti-vibration crystal oscillator. Background Art

[0002] The vibration resistance of electronic components is an important indicator to measure their performance. Components with poor vibration resistance will bring many uncontrollable variables when working in a vibration environment, and may even directly affect the operation of the entire system, causing system failure. Therefore, improving the vibration resistance of electronic components is crucial to ensure the normal operation of electronic systems.

[0003] The traditional method of enhancing the vibration resistance of electronic components is to add vibration-damping pads, which has the problems of poor vibration-damping effect, difficult structural design, larger size than ordinary crystal oscillators, and a certain displacement of the crystal oscillator in a vibration environment due to the compression and relaxation of the vibration-damping pads. Summary of the invention

[0004] The present invention provides a dual-resonator anti-vibration crystal oscillator to solve the problems existing in the prior art, such as poor vibration reduction effect, increased difficulty in structural design, larger size than ordinary crystal oscillators, and certain displacement of the crystal oscillator in a vibration environment due to the movement of the crystal oscillator driven by compression and relaxation of the vibration reduction pad.

[0005] The present invention provides a dual-resonator anti-vibration crystal oscillator, comprising a bare chip, a base and two crystal resonators, wherein:

[0006] The bare chip is bonded to the inside of the cavity of the base, and the pads of the bare chip are electrically connected to the ports inside the base;

[0007] The two crystal resonators are symmetrically connected to the base in reverse order and are connected in parallel to the exposed chip.

[0008] Optionally, the packaging form of the base is SMD7050.

[0009] Optionally, the base is a ceramic base.

[0010] Optionally, the crystal resonator is packaged in SMD2520.

[0011] Optionally, the bare chip is bonded inside the cavity of the base by conductive adhesive.

[0012] Optionally, the electrical connection between the pads of the exposed chip and the ports inside the base is achieved through gold wire bonding.

[0013] Optionally, the ports inside the base include air, ground, output and power supply.

[0014] Optionally, the two crystal resonators are symmetrically and reversely connected to the base by welding.

[0015] Optionally, three filter capacitors are further included, and the three filter capacitors are respectively connected to the base and connected in parallel to the exposed chip, and the capacitance values ​​of the three filter capacitors are determined by the filtering frequency range.

[0016] Optionally, the three filter capacitors are respectively connected to the base by welding.

[0017] The present invention provides a crystal oscillator with excellent anti-vibration performance, which solves the problem that a traditional crystal oscillator has a large phase noise when working in a vibration environment, realizes mutual cancellation of noises of two resonators on the crystal oscillator, reduces the noise level of the crystal oscillator, and improves the anti-vibration performance of the crystal oscillator; reduces the difficulty of structural design by using an exposed chip; no vibration damping pad is needed for vibration resistance, the size is not increased compared with an ordinary crystal oscillator, and displacement in a vibration environment is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of the structure of a dual-resonator anti-vibration crystal oscillator provided in an embodiment of the present invention, wherein:

[0020] 1 is a bare chip, 2 is a SMD7050 ceramic base, 3 and 4 are SMD2520 crystal resonators, and 5, 6 and 7 are filter capacitors. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Some terms used in the embodiments are described below to facilitate understanding by those skilled in the art.

[0023] SMD: The abbreviation of Surface-Mount Device, which refers to surface mount device.

[0024] 7050: indicates the dimensions are 7.0 x 5.0 mm.

[0025] 2520: indicates the dimensions are 2.5 x 2.0 mm.

[0026] A dual-resonator anti-vibration crystal oscillator provided in an embodiment of the present invention includes a bare chip, a base and two crystal resonators.

[0027] The bare chip is bonded inside the cavity of the base, and the pads of the bare chip are electrically connected to the ports inside the base.

[0028] The bare chip is used to provide electrical energy and process signals. Compared with the PCB board, the bare chip has a high circuit integration and a simplified structure.

[0029] In one example, the package form of the base is SMD7050.

[0030] In one example, the base is a ceramic base, which is a common material in the industry and can ensure mechanical strength.

[0031] In one example, the bare chip is bonded to the inside of the cavity of the base by conductive adhesive. In addition to bonding the bare chip to the inside of the cavity of the base, the conductive adhesive can also connect the power ground of the bare chip to the inner shell of the base, playing a role in stabilizing the ground. Usually, the crystal oscillator can also work without connecting the power ground of the bare chip to the inner shell of the base.

[0032] In one example, the electrical connection between the pads of the exposed chip and the ports inside the base is achieved through gold wire bonding, and the electrical connection method of gold wire bonding is more adaptable to the environment.

[0033] In one example, the ports inside the base include air, ground, output, and power, where air is #1 (ie, the first port), ground is #2, output is #3, and power is #4.

[0034] The two crystal resonators are connected symmetrically and in reverse order on the base and connected in parallel on the exposed chip.

[0035] The crystal resonator utilizes the piezoelectric effect of quartz crystal. When an alternating voltage is applied to the quartz crystal chip, the chip will produce periodic mechanical vibrations with the frequency of the alternating voltage; at the same time, the mechanical vibration generates charges on the chip to form an alternating current. The quartz crystal resonator based on the above working principle is sensitive to acceleration. When the crystal oscillator works in a vibration environment, the crystal oscillator will be frequency modulated, which seriously deteriorates the phase noise of the crystal oscillator. Placing the two resonators symmetrically in reverse makes the resonators act in opposite directions. When affected by vibration, the forces can offset each other, thereby reducing noise. The vibration in the crystal oscillator is the self-excited vibration of the internal frequency chip. The vibration in the external environment will affect the self-excited vibration of the internal frequency chip, aggravating the phase noise of the crystal oscillator. Reducing noise means improving the vibration resistance of the crystal oscillator.

[0036] In one example, the crystal resonator is packaged in SMD2520.

[0037] The two crystal resonators respectively form an oscillating electrical loop with the bare chip, and the bare chip provides power and processes signals.

[0038] In one example, two crystal resonators are symmetrically connected to the base in opposite directions by welding.

[0039] The above scheme provides a crystal oscillator with excellent vibration resistance, which solves the problem that traditional crystal oscillators have large phase noise when working in a vibration environment, realizes the mutual cancellation of the noise of the two resonators on the crystal oscillator, reduces the noise level of the crystal oscillator, and improves the vibration resistance of the crystal oscillator; reduces the difficulty of structural design by using exposed chips; no vibration damping pads are required for vibration resistance, the size is not increased compared to ordinary crystal oscillators, and displacement in a vibration environment is avoided.

[0040] In one example, a dual-resonator anti-vibration crystal oscillator provided by the present invention also includes three filter capacitors, which are respectively connected to the base and connected in parallel on the exposed chip, and the capacitance values ​​of the three filter capacitors are determined by the filtering frequency range.

[0041] The two ends of the filter capacitor are actually connected to the power supply and ground of the exposed chip to filter out the noise on the power supply.

[0042] The embodiment of the present invention takes into account the filtering frequency range and selects one 0.1uF and two 0.01uF capacitors. The 0.1uF capacitor filters out clutter from 100kHz to 10MHz, and the 0.01uF capacitor filters out clutter from 10MHz to 100MHz. The combination of large and small capacitors covers a wider filtering frequency range, and the use of two small capacitors enhances the high-frequency filtering performance.

[0043] Furthermore, the three filter capacitors are respectively connected to the base by welding.

[0044] Figure 1 The structure of a dual-resonator anti-vibration crystal oscillator is shown, wherein 1 is a bare chip, 2 is an SMD7050 ceramic base, 3 and 4 are SMD2520 crystal resonators, and 5, 6 and 7 are filter capacitors.

[0045] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0046] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A dual-resonator anti-vibration crystal oscillator, characterized in that: It includes a bare chip, a base and two crystal resonators, where: The bare chip is bonded to the inside of the cavity of the base, and the pads of the bare chip are electrically connected to the ports inside the base; The two crystal resonators are symmetrically connected to the base in reverse order and are connected in parallel to the exposed chip.

2. The crystal oscillator according to claim 1, characterized in that: The packaging form of the base is SMD7050.

3. The crystal oscillator according to claim 1, characterized in that: The base is a ceramic base.

4. The crystal oscillator according to claim 1, characterized in that: The packaging form of the crystal resonator is SMD2520.

5. The crystal oscillator according to claim 1, characterized in that: The bare chip is bonded inside the cavity of the base by conductive adhesive.

6. The circuit according to claim 1, characterized in that: The electrical connection between the pads of the exposed chip and the ports inside the base is achieved through gold wire bonding.

7. The circuit according to claim 1, characterized in that: The ports inside the base include air, ground, output and power supply.

8. The circuit according to claim 1, characterized in that: The two crystal resonators are symmetrically and reversely connected to the base by welding.

9. The circuit according to claim 1, characterized in that: It also includes three filter capacitors, which are respectively connected to the base and connected in parallel to the exposed chip. The capacitance values ​​of the three filter capacitors are determined by the filter frequency range.

10. The circuit according to claim 9, characterized in that: The three filter capacitors are respectively connected to the base by welding.

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