High-gain automatic phase modulation quartz vibrating beam accelerometer control circuit

Abstract

A high-gain automatic phase modulation quartz vibrating beam accelerometer control circuit comprises a feed-through suppression module, the feed-through suppression module and a quartz vibrating beam resonator form a parallel resonance unit, and the output of the parallel resonance unit is connected with the input of a front-end amplification module. The output of the front-end amplification module is connected with the input of the high-pass filtering module and the first input of the automatic phase control module, the output of the high-pass filtering module is connected with the first input of the dynamic phase shift module, and the second input of the dynamic phase shift module is connected with the output of the automatic phase control module. The output of the dynamic phase shift module is connected with the input of the differential driving module through the low-pass filtering module, the square wave shaping module and the amplitude control module; the output of the differential driving module is connected with the input of the feed-through suppression module, the driving end of the quartz vibrating beam resonator and the second input of the automatic phase control module; according to the invention, low-noise driving of the high-impedance quartz vibrating beam is realized, and the loop phase error is dynamically compensated to improve the stability and resolution of the accelerometer.

Description

Technical Field

[0001] The invention belongs to the technical field of micro-electromechanical system (MEMS) inertial instruments or inertial devices, and in particular relates to a high-gain automatic phase-modulated quartz vibration beam accelerometer control circuit. Background Art

[0002] Inertial sensors based on the resonance principle play an increasingly important role in navigation and guidance, gravity detection, oil exploration and other fields with their advantages of high precision, high stability and high resolution. The quartz vibrating beam accelerometer is a type of resonant accelerometer. The vibrating beam resonator made based on the unique piezoelectric properties of quartz can achieve extremely high quality factors. The ultra-stable lattice structure ensures its long-term stability and repeatability when working in complex environments. It is the preferred solution for high-precision acceleration measurement. The quartz vibrating beam accelerometer can modulate the inertial force in the sensitive direction to the continuously oscillating carrier frequency and output a stable quasi-digital signal. It can be directly input into the digital system for processing without the traditional analog-to-digital conversion link, which improves the measurement accuracy while reducing the production cost.

[0003] The control circuit of the quartz vibration beam accelerometer currently mainly adopts an inverter-based feedback scheme, such as the patent application entitled "A Signal Processing Circuit Based on Quartz Resonator" (Publication No.: CN207910744U). This scheme detects the output signal of the quartz vibration beam by biasing the inverter in its linear operating region. The second-stage inverter compensates for the phase required for positive feedback to form a self-excited oscillation. Although the inverter has an extremely high linear gain, for the quartz vibration beam with distributed noise, the gain of the transimpedance inverter as the front-end circuit is constrained by bandwidth and noise, which limits the resolution of the accelerometer. In order to drive the high-impedance quartz vibration beam, an excitation circuit based on a two-stage inverter front end is proposed, such as the patent application named "An excitation circuit for a quartz resonant accelerometer" (publication number: CN110988397A), which adds a first-stage inverting amplifier after the front end of the traditional control circuit. Although this solution alleviates the gain and bandwidth constraints of the front-end circuit, the added amplifier will introduce more noise, which will eventually be modulated to the carrier sideband through the closed-loop circuit and increase the phase noise of the system, which is manifested as an increase in the white noise and quantization noise output by the quartz vibration beam accelerometer, reducing the stability and resolution of the accelerometer. In addition, the existing quartz vibration beam accelerometer control circuits are all fixed phase feedback. Although they can compensate for the phase deviation caused by non-ideal factors to a certain extent, when the accelerometer works in the full scale and full temperature range, the resonant frequency and phase error will be offset, and the fixed phase feedback will introduce excessive or even opposite phase compensation, resulting in poor system performance and reducing the scale factor and full temperature stability and repeatability of the accelerometer. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a high-gain automatic phase modulation quartz beam accelerometer control circuit to achieve low-noise driving of the high-impedance quartz beam and dynamically compensate for the loop phase error to improve the stability and resolution of the accelerometer.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A high-gain automatic phase modulation quartz vibration beam accelerometer control circuit comprises a feedthrough suppression module, the feedthrough suppression module and a quartz vibration beam resonator are connected in parallel to form a parallel resonance unit, the output of the parallel resonance unit is connected to the input of a front-end amplifier module, the output of the front-end amplifier module is connected to the input of a high-pass filter module and the first input of an automatic phase control module, the output of the high-pass filter module is connected to the first input of a dynamic phase shift module, the second input of the dynamic phase shift module is connected to the output of the automatic phase control module, the output of the dynamic phase shift module is connected to the input of a low-pass filter module, the output of the low-pass filter module is connected to the input of a square wave shaping module, the output of the square wave shaping module is connected to the input of an amplitude control module, the output of the amplitude control module is connected to the input of a differential drive module, the output of the differential drive module is connected to the input of the feedthrough suppression module, the driving end of the quartz vibration beam resonator and the second input of the automatic phase control module.

[0007] The feedthrough suppression module is implemented by using a compensation capacitor.

[0008] The front-end amplification module is composed of a two-stage dual-port network consisting of an operational amplifier, a resistor and a capacitor, with the two stages connected in series; or it can be implemented by any number and combination of integrators and differentiators such as a single-stage integrator, an integrator-integrator cascade, a differentiator-differentiator cascade, etc.

[0009] The high-pass filter module and the low-pass filter module are implemented in a second-order active manner and can be replaced by passive filters or higher-order active filters.

[0010] The dynamic phase shift module is composed of an active phase shifter and a voltage-controlled variable resistor, and the voltage-controlled variable resistor is formed by two P-channel metal oxide semiconductor field effect transistors (PMOS) connected in parallel.

[0011] The square wave shaping module is implemented by using a comparator, or an operational amplifier operating in an open loop.

[0012] The amplitude control module is implemented by using a negative feedback operational amplifier.

[0013] The differential driving module is implemented by a differential driver.

[0014] The automatic phase control module includes an analog-to-digital converter, a phase frequency detector (PFD), a low-pass filter, a PID controller and a digital-to-analog converter. The automatic phase control module is implemented using a digital circuit. The analog-to-digital converter converts analog signals output by the differential drive module and the front-end amplifier module into digital signals respectively, and enters the phase frequency detector (PFD). The phase frequency detector (PFD) is connected to the low-pass filter to output a voltage signal that is proportional to the phase difference between the two input signals. The PID controller converts the output signal of the low-pass filter into a control signal, which is output as a control signal of a voltage-controlled variable resistor in the dynamic phase shift module after passing through the digital-to-analog converter. The change in resistance causes the phase of the control circuit to advance or lag, thereby eliminating the deviation between the oscillation frequency of the loop and the natural frequency of the quartz beam resonator.

[0015] The phase frequency detector (PFD) is composed of a D trigger, an AND gate, an inverter, a PMOS and an NMOS connected in sequence, and the low-pass filter and the PID controller are implemented by digital circuits; or by analog circuits.

[0016] The phase frequency detector (PFD) adopts a multiplication phase detector, an EXOR phase detector, a JK trigger phase detector, etc.

[0017] The control circuit is composed of a mixture of analog circuits and digital circuits, or is implemented through integrated circuit (ASIC) technology.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The front-end amplifier module decouples the constraints between gain and bandwidth, and can provide higher gain for the quartz beam resonator within a large bandwidth. Using capacitors as the main gain element will not introduce additional noise, achieving a higher output signal-to-noise ratio and improving the resolution and stability of the quartz beam accelerometer.

[0020] (2) The automatic phase control module can detect the phase difference between the driving signal of the quartz beam resonator and the output signal of the front-end amplifier module in real time, and control the dynamic phase shift module to adjust the oscillation frequency of the loop to follow the natural frequency of the quartz beam resonator, thereby ensuring the linearity of the scale factor of the quartz beam accelerometer. The improvement of the effective quality factor also greatly enhances the stability and resolution of the accelerometer.

[0021] (3) The circuit of the present invention can be implemented through application-specific integrated circuit (ASIC) technology, thereby further reducing system power consumption and cost and realizing the miniaturization of the inertial navigation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a circuit block diagram of an embodiment of the present invention.

[0023] Figure 2Schematic diagram of the circuit structure and noise of the front-end amplifier module according to an embodiment of the present invention.

[0024] Figure 3 It is a circuit diagram of a high-pass filtering module, a dynamic phase shifting module, a low-pass filtering module, a square wave shaping module, an amplitude control module, and a differential driving module according to an embodiment of the present invention.

[0025] Figure 4 Schematic diagram of a circuit of an automatic phase control module according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0027] like Figure 1 As shown, a high-gain automatic phase modulation quartz vibration beam accelerometer control circuit includes a feedthrough suppression module 2, the feedthrough suppression module 2 and the quartz vibration beam resonator 1 are connected in parallel to form a parallel resonance unit, the output of the parallel resonance unit is connected to the input of the front-end amplifier module 3, the output of the front-end amplifier module 3 is connected to the input of the high-pass filter module 4 and the first input of the automatic phase control module 6, the front-end amplifier module 3 and the high-pass filter module 4 form an interface signal extraction unit; the output of the high-pass filter module 4 is connected to the first input of the dynamic phase shift module 5, the second input of the dynamic phase shift module 5 is connected to the output of the automatic phase control module 6, and the dynamic phase shift module 6 is connected to the output of the automatic phase control module 6. The output of the phase module 5 is connected to the input of the low-pass filter module 7, the output of the low-pass filter module 7 is connected to the input of the square wave shaping module 8, the output of the square wave shaping module 8 is connected to the input of the amplitude control module 9, the output of the amplitude control module 9 is connected to the input of the differential drive module 10, the output of the differential drive module 10 is connected to the input of the feedthrough suppression module 2, the driving end of the quartz beam resonator 1, and the second input of the automatic phase control module 6, the automatic phase control module 6 and the dynamic phase shift module 5 form a dynamic phase modulation unit, the low-pass filter module 7 and the square wave shaping module 8 form the output stage of the control circuit, and drive the amplitude control module 9.

[0028] When the control circuit is connected to the power supply, the instantaneous current generates distributed noise, and the output noise of the differential drive module 10 drives the quartz beam resonator 1 to perform random vibration, and the thermal noise generated by the Brownian motion of the quartz beam resonator 1 itself is superimposed, and converted into an electrical signal recognizable by the circuit through the inverse piezoelectric effect, and converted into a high-gain voltage signal by the front-end amplifier module 3, and fed back to the driving end of the quartz beam resonator 1 through the subsequent high-pass filter module 4, dynamic phase shift module 5, low-pass filter module 7, square wave shaping module 8, amplitude control module 9 and differential drive module 10, forming a positive feedback loop; when the loop meets the self-excited oscillation Condition, that is, when the loop gain is greater than 1 and the phase error is 0, the amplitude of the quartz beam resonator 1 will be continuously amplified and finally stabilized at the maximum amplitude that the driving signal can produce. At this time, the loop gain is equal to 1; the quartz beam resonator 1 has an extremely high quality factor, and the noise is almost completely suppressed outside the passband. The signal within the passband obtains high gain to form oscillation, and the control circuit will work at the natural frequency of the quartz beam resonator 1 after startup; the vibration amplitude of the quartz beam resonator 1 is determined by the amplitude control module 9, and the maximum signal-to-noise ratio and the lowest phase noise are achieved without exciting significant nonlinear dynamic characteristics.

[0029] When an acceleration load appears in the sensitive direction of the quartz beam accelerometer, the quartz beam resonator 1 is subjected to axial stress, the natural frequency will shift, and the center frequency of the loop passband will also shift to the same extent. The oscillation frequency of the control circuit always follows the natural frequency change of the quartz beam resonator 1, and can detect the load acceleration with high precision. The material parameters of the quartz beam resonator 1 will drift in a variable temperature environment. The thermal stress and packaging prestress generated by the integration of heterogeneous materials will cause the natural frequency of the quartz beam resonator 1 to drift unpredictably. Within the limited loop bandwidth, the oscillation frequency will deviate from the natural frequency of the quartz beam resonator 1, reducing the effective quality factor of the control circuit. The automatic phase control module 6 collects the signal of the driving end of the quartz beam resonator 1 and the output signal of the front-end amplifier module 3 for comparison, controls the dynamic phase shift module 5 to adjust the loop phase, eliminates the error between the oscillation frequency and the natural frequency of the quartz beam resonator, and improves the linearity and stability of the scale factor of the accelerometer.

[0030] The control circuit of this embodiment is a closed-loop self-excited oscillation system, which does not require an input signal. After being powered on, it can be excited by distributed noise and automatically oscillate at the natural frequency of the quartz beam resonator 1; the square wave signal output by the square wave shaping module 8 is used as the output of the control circuit, and its frequency represents the acceleration to which the quartz beam accelerometer is sensitive.

[0031] like Figure 2As shown in (a), the front-end amplification module 3 is composed of operational amplifiers U1 and U2, resistors R1 and R2, capacitors C1, C2 and C3. The inverting input terminal of the operational amplifier U1 is connected to the output terminal of the quartz beam resonator 1, and the resistor R1 and the capacitor C1 are connected in parallel to the inverting input terminal and the output terminal of the operational amplifier U1; the output terminal of the operational amplifier U1 is connected to one end of the capacitor C2, and the other end of the capacitor C2 is connected to the inverting input terminal of the operational amplifier U2; the capacitor C3 and the resistor R2 are connected in parallel to the inverting input terminal and the output terminal of the operational amplifier U2; the operational amplifier U1, the resistor R1 and the capacitor C1 form a first-stage front-end interface circuit, and the operational amplifier U2, the capacitors C2, C3 and the resistor R2 form a second-stage amplification circuit; the first-stage front-end interface circuit is equivalent to an integrator, which provides high gain through the capacitor C1, and the resistor R1 provides a DC feedback path for the operational amplifier U1 to avoid output signal saturation caused by the input bias voltage; the capacitor C s and C in The input and parasitic capacitances constitute the front-end amplifier module 3; the second-stage amplifier circuit is equivalent to a differentiator, which provides a stable AC gain for the front-end amplifier module 3 within the operating frequency range of the quartz beam resonator 1. The gain is determined by the capacitor C2 and the resistor R2, and the bandwidth is determined by the capacitor C3; the front-end amplifier module 3 has a bandpass characteristic, and the gain in the passband is (C2 / C1)R2.

[0032] Compared with the traditional transimpedance inverter front-end circuit, the front-end amplifier module 3 has the following advantages: (1) It decouples the constraints between the gain and bandwidth of the traditional transimpedance inverter front-end circuit. The gain of the front-end amplifier module 3 is provided by capacitors C2 and C1, and the resistor R2 can take a small value, so that an operational amplifier with the same gain-bandwidth product or an inverter working in the linear region can release a larger bandwidth performance. (2) It achieves lower noise. The transimpedance inverter front-end circuit provides gain by capacitors, so it will obtain lower noise than the traditional inverter that relies on resistors to provide gain. At the same time, the noise of operational amplifiers U1 and U2 is significantly suppressed by the first-stage integrator, and the thermal noise of resistor R2 is suppressed by the capacitor ratio C2 / C1. (3) Since the first-stage front-end interface circuit uses a large resistor R1, it has sufficient phase margin and there is no stability risk. The second-stage amplifier circuit can ignore the input bias voltage due to its own differential characteristics, thereby improving the accuracy of signal detection.

[0033] like Figure 2As shown in (b), the noise of the front-end amplifier module 3 includes the noise of the operational amplifier U1, the operational amplifier U2, and the noise of the resistor R1, the resistor R2; the total noise is dominated by the noise of the resistor R2 in the low frequency band and the working frequency band, but because the capacitor C2 / C1 provides most of the gain, the noise of the resistor R2 is much smaller than the resistor noise of the traditional inverter; in the high frequency band greater than the working frequency band, the total noise is mainly dominated by the noise of the operational amplifier U1, because the differential characteristics of the second-stage amplifier circuit provide a higher gain for the high-frequency noise.

[0034] The front-end amplifier module 3 can also be implemented by any number and combination of integrators and differentiators such as a single-stage integrator, an integrator-integrator cascade, a differentiator-differentiator cascade, etc.

[0035] like Figure 3 As shown, the circuits of the high-pass filter module, dynamic phase shift module, low-pass filter module, square wave shaping module, amplitude control module, and differential drive module are composed of operational amplifiers U3, U4, U5, U7, and U8, a comparator U6, resistors R3, R4, R5, R6, R7, R8, R9, and R 10 , R 11 , R 12 , R 13 , R 14 , capacitors C4, C5, C6, C7, C8, MOS tubes M1, M2, wherein operational amplifier U3, resistors R3, R4, R5, R6, capacitors C4, C5 form a high-pass filter module 4; operational amplifier U4, resistors R7, R8, MOS tubes M1, M2 form a dynamic phase shift module 5; operational amplifier U5, resistors R9, R 10 , R 11 , R 12 , capacitor C7 forms low-pass filter module 7; comparator U6 serves as square wave shaping module 8; operational amplifier U7, resistor R 13 , R 14 The amplitude control module 9 is formed; the differential driver U8 and the capacitor C8 form a differential driving module 10.

[0036] The high-pass filter module 4 includes an input capacitor C4, which is connected to the output terminal V sThe other end of the input capacitor C4 is connected to capacitor C5 and resistor R6, the other end of capacitor C5 is connected to the non-inverting input of the operational amplifier U3, and the other end of resistor R6 is connected to the output of the operational amplifier U3; one end of resistor R5 is connected to the non-inverting input of the operational amplifier U3, and the other end is grounded; one end of resistor R3 is connected to the inverting input of the operational amplifier U3, and the other end is grounded; one end of resistor R4 is connected to the inverting input of the operational amplifier U3, and the other end is connected to the output of the operational amplifier U3; resistor R3 and resistor R4 form a negative feedback network of the operational amplifier U3.

[0037] The dynamic phase shift module 5 includes a capacitor C6, one end of the capacitor C6 and the resistor R7 are simultaneously connected to the output end of the high-pass filter module 4, that is, the output end of the operational amplifier U3, and the other ends of the capacitor C6 and the resistor R7 are respectively connected to the in-phase input end and the inverting input end of the operational amplifier U4; the resistor R8 is connected in parallel between the inverting input end and the output end of the operational amplifier U4, and forms a negative feedback network of the operational amplifier U4 with the resistor R7; the MOS tube M1 and the MOS tube M2 are connected in parallel, the gate of the MOS tube M1 is connected to the in-phase input end of the operational amplifier U4, and the gate of the MOS tube M1 is connected to its own drain, forming a voltage-controlled variable resistor, and the control voltage V c The gate of the MOS tube M2 is input, and the drains of the MOS tubes M1 and M2 are grounded together.

[0038] The low-pass filter module 7 includes a resistor R9, which is connected to the output end of the dynamic phase shift module 5, that is, the output end of the operational amplifier U4, and the other end of the resistor R9 is connected to the resistor R 10 , capacitor C7, resistor R 10 The other end of the capacitor C7 is connected to the non-inverting input of the operational amplifier U5, the other end of the capacitor C7 is grounded, and the resistor R 11 , resistor R 12 One end of the resistor R 11 The other end is grounded, and the resistor R 12 The other end is connected to the output of operational amplifier U5, and the resistor R 11 and R 12 It forms the negative feedback network of operational amplifier U5.

[0039] The square wave shaping module 8 adopts a comparator U6, and the input end of the comparator U6 is connected to the output end of the low-pass filtering module 7, that is, the output end of the operational amplifier U5.

[0040] The amplitude control module 9 includes a resistor R 13 , resistor R 13 One end is connected to the output end of the square wave shaping module 8, that is, the output end of the comparator U6, and the resistor R 13 The other end and resistor R 14Connect the inverting input of operational amplifier U7 and resistor R 14 The other end is connected to the output end of the operational amplifier U7, and the non-inverting input end of the operational amplifier U7 is grounded.

[0041] The differential drive module 10 includes a differential driver U8, the in-phase input end of the differential driver U8 is connected to the output end of the amplitude control module 9, that is, the output end of the operational amplifier U7, the inverting input end of the differential driver U8 is grounded, the in-phase output end of the differential driver U8 is connected to the driving end of the quartz beam resonator 1, and the inverting output end of the differential driver U8 is connected to the capacitor C s , capacitor C s The other end is connected to the output end 11 of the quartz beam resonator 1.

[0042] The front-end amplifier module 3 detects the vibration signal of the quartz beam resonator 1 and converts it into a high-gain voltage output. The high-pass filter module 4 filters out the low-frequency useless signal and transmits it to the dynamic phase shifter. After automatic phase modulation, it outputs an oscillation signal with zero phase difference from the quartz beam resonator 1. The square wave shaping module uses a special comparator, which can quickly and distortion-free convert the sinusoidal signal into a square wave signal that can be directly processed by the digital system. Since the natural frequency of the quartz beam resonator 1 is much lower than the bandwidth of the control circuit, undersampling is performed during the square wave shaping process, and high-frequency noise higher than the natural frequency of the quartz beam resonator 1 is modulated into the vicinity of the carrier, reducing the system signal-to-noise ratio. The low-pass filter module 7 is inserted before the square wave shaping module 8 to limit the loop bandwidth to reduce the noise aliasing of the next level and improve the stability and resolution of the accelerometer. The signal-to-noise ratio of the quartz beam resonator 1 is proportional to its amplitude, but an excessively large amplitude will cause the system to enter a nonlinear state, where its natural frequency is modulated by the amplitude, directly converting the amplitude noise into frequency noise, reducing the linearity and stability of the accelerometer's scale factor. The amplitude control module 9 is used to ensure that the quartz beam resonator 1 obtains the highest signal-to-noise ratio in the linear operating region. Different quartz beam resonators 1 can be flexibly and conveniently adjusted without any structural changes, which can greatly reduce production costs and unleash the ideal performance of the device. The in-phase and anti-phase output terminals of the differential drive module 10 drive the quartz beam resonator 1 and the compensation capacitor C respectively. s , the static capacitance of the quartz beam resonator 1 and the compensation capacitance C s The generated output signals cancel each other out, retaining the vibration signal of the quartz beam resonator 1 and eliminating undesired parasitic oscillations.

[0043] The high-pass filter module 4 and the low-pass filter module 7 can also be implemented by passive circuits or three-level or higher active circuits.

[0044] The square wave shaping module 8 can also be implemented by an operational amplifier or a discrete MOS tube.

[0045] like Figure 4 As shown, the automatic phase control module 6 is composed of an analog-to-digital converter U9, an analog-to-digital converter U10, a D flip-flop U11, a D flip-flop U12, an AND gate U13, an inverter U14, a MOS tube M3, a MOS tube M4, a low-pass filter 13, a PID controller 14 and a digital-to-analog converter U15, wherein the D flip-flop U11, the D flip-flop U12, the AND gate U13, the inverter U14, the MOS tube M3, and the MOS tube M4 are connected to form a phase frequency detector (PFD); the automatic phase control module 6 is implemented by a digital circuit, and the analog-to-digital converter U9 and the analog-to-digital converter U10 connect the driving end 12 of the differential driving module 10 and the output end V s The analog signal is converted into a digital signal and enters the phase frequency detector (PFD). When the driving end 12 signal passes through the rising edge, the phase frequency detector (PFD) outputs a high level. s When the signal passes through the rising edge, the phase frequency detector (PFD) outputs a low level; a voltage signal proportional to the phase difference between the two input signals can be obtained through the low-pass filter 13. The PID controller 14 converts the output signal of the low-pass filter 13 into a control signal, and outputs an analog signal V after passing through the digital-to-analog converter U15. c , controlling the voltage-controlled variable resistor composed of MOS tube M1 and MOS tube M2 in the dynamic phase shift module 5, the resistance change causes the phase advance or lag of the control circuit, ensuring that the oscillation frequency of the loop is always consistent with the natural frequency of the quartz beam resonator 1.

[0046] The automatic phase control module 6 may also be implemented using an analog circuit.

[0047] The phase frequency detector (PFD) may also be a multiplication phase detector, an EXOR phase detector, a JK trigger phase detector, etc.

[0048] The entire control circuit of this embodiment can be implemented by a combination of analog circuits and digital circuit chips of discrete devices, or by application specific integrated circuit (ASIC) technology.

Claims

1. A high-gain automatic phase modulation quartz beam accelerometer control circuit, including a feedthrough suppression module, characterized in that: The feedthrough suppression module is connected in parallel with the quartz vibration beam resonator to form a parallel resonance unit. The output of the parallel resonance unit is connected to the input of the front-end amplifier module, the output of the front-end amplifier module is connected to the input of the high-pass filter module and the first input of the automatic phase control module, the output of the high-pass filter module is connected to the first input of the dynamic phase shift module, the second input of the dynamic phase shift module is connected to the output of the automatic phase control module, the output of the dynamic phase shift module is connected to the input of the low-pass filter module, the output of the low-pass filter module is connected to the input of the square wave shaping module, the output of the square wave shaping module is connected to the input of the amplitude control module, the output of the amplitude control module is connected to the input of the differential drive module, the output of the differential drive module is connected to the input of the feedthrough suppression module, the driving end of the quartz vibration beam resonator, and the second input of the automatic phase control module.

2. The high-gain automatic phase modulation quartz beam accelerometer control circuit according to claim 1, characterized in that: The front-end amplification module includes an operational amplifier U1, the inverting input end of the operational amplifier U1 is connected to the output end of the quartz beam resonator, the resistor R1 and the capacitor C1 are connected in parallel to the inverting input end and the output end of the operational amplifier U1; the output end of the operational amplifier U1 is connected to one end of the capacitor C2, and the other end of the capacitor C2 is connected to the inverting input end of the operational amplifier U2; the capacitor C3 and the resistor R2 are connected in parallel to the inverting input end and the output end of the operational amplifier U2; the operational amplifier U1, the resistor R1 and the capacitor C1 form a first-stage front-end interface circuit, and the operational amplifier U2, the capacitors C2, C3 and the resistor R2 form a second-stage amplification circuit; The first-stage front-end interface circuit is equivalent to an integrator, which provides high gain through capacitor C1, and resistor R1 provides a DC feedback path for operational amplifier U1 to avoid output signal saturation caused by input bias voltage; The second-stage amplifier circuit is equivalent to a differentiator, which provides a stable AC gain for the front-end amplifier module within the operating frequency range of the quartz beam resonator. The gain is determined by capacitor C2 and resistor R2, and the bandwidth is determined by capacitor C3. The front-end amplifier module has a bandpass characteristic, and the gain in the passband is (C2 / C1)R2.

3. The high-gain automatic phase modulation quartz beam accelerometer control circuit according to claim 1, characterized in that: The automatic phase control module includes an analog-to-digital converter, a phase frequency detector (PFD), a low-pass filter, a PID controller and a digital-to-analog converter. The automatic phase control module is implemented using a digital circuit. The analog-to-digital converter converts analog signals output by the differential drive module and the front-end amplifier module into digital signals respectively, and enters the phase frequency detector (PFD). The phase frequency detector (PFD) is connected to the low-pass filter to output a voltage signal that is proportional to the phase difference between the two input signals. The PID controller converts the output signal of the low-pass filter into a control signal, which is output as a control signal of a voltage-controlled variable resistor in the dynamic phase shift module after passing through the digital-to-analog converter. The change in resistance causes the phase of the control circuit to advance or lag, thereby eliminating the deviation between the oscillation frequency of the loop and the natural frequency of the quartz beam resonator.

4. The automatic phase control module according to claim 3, characterized in that: The phase frequency detector (PFD) is composed of a D trigger, an AND gate, an inverter, a PMOS and an NMOS connected in sequence, and the low-pass filter and the PID controller are implemented by digital circuits; or by analog circuits.

5. The automatic phase control module according to claim 3, characterized in that: The phase frequency detector (PFD) adopts a multiplication phase detector, an EXOR phase detector or a JK trigger phase detector.

6. The high-gain automatic phase modulation quartz beam accelerometer control circuit according to claim 1, characterized in that: The high-pass filter module and the low-pass filter module are implemented in a second-order active manner and can be replaced by passive filters or higher-order active filters.

7. The high-gain automatic phase modulation quartz beam accelerometer control circuit according to claim 1, characterized in that: The dynamic phase shift module is composed of an active phase shifter and a voltage-controlled variable resistor, and the voltage-controlled variable resistor is formed by two P-channel metal oxide semiconductor field effect transistors (PMOS) connected in parallel.

8. The high-gain automatic phase modulation quartz beam accelerometer control circuit according to claim 1, characterized in that: The square wave shaping module is implemented by using a comparator, or an operational amplifier operating in an open loop.

9. The high-gain automatic phase modulation quartz beam accelerometer control circuit according to claim 1, characterized in that: The feedthrough suppression module is implemented by using a compensation capacitor; the amplitude control module is implemented by using a negative feedback operational amplifier; and the differential drive module is implemented by using a differential driver.

10. The high-gain automatic phase modulation quartz beam accelerometer control circuit according to claim 1, characterized in that: The control circuit is composed of a mixture of analog circuits and digital circuits, or is implemented through integrated circuit (ASIC) technology.

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