A MEMS gyroscope fourth-order feedforward sigma-delta closed-loop detection circuit

Abstract

This invention discloses a 4th-order feedforward Sigma-Delta closed-loop detection circuit for a MEMS gyroscope. The circuit includes a MEMS gyroscope, a transimpedance amplifier, an instrumentation amplifier, a high-precision ADC, a digital conversion circuit (including a compensator, a resonant circuit, and a quantizer), a one-bit DAC, an analog switch, a demodulator, and a low-pass filter. The current signal output from the gyroscope's sensitive detection is amplified and converted from analog to digital before being fed into the digital conversion circuit. A notch filter effect is created at the center frequency using a resonant circuit corresponding to the gyroscope's detection mode resonant frequency to suppress the resonant peak. The 1-bit density-modulated digital signal output from the quantizer is fed back to the gyroscope detection terminal through the one-bit DAC and analog switch, forming an electrostatic force closed-loop feedback. The other path is demodulated and low-pass filtered to output the angular velocity detection result. This invention effectively suppresses in-band noise and improves closed-loop bandwidth, exhibits high linearity, and is easily implemented using FPGA or dedicated integrated circuits.

Description

Technical Field

[0001] This invention belongs to the field of inertial sensor detection technology, and in particular to a MEMS gyroscope fourth-order feedforward Sigma-Delta closed-loop detection circuit. Background Technology

[0002] MEMS gyroscopes, with their advantages of small size, low power consumption, ease of mass production, and convenient system integration, have been widely used in inertial navigation, attitude measurement, platform stabilization, and consumer electronics. MEMS gyroscopes maintain the vibration of the sensitive structure through driving modes. When an external angular velocity input is present, the Coriolis effect generates a weak detection signal related to the angular velocity in the detection mode. Because this detection signal has a small amplitude and is susceptible to circuit noise and mechanical thermal noise, the noise performance, dynamic range, closed-loop stability, and electrode feedback method of the detection circuit directly affect the zero-bias stability, bandwidth, and signal-to-noise ratio of the MEMS gyroscope.

[0003] Existing MEMS gyroscope detection circuits can employ either open-loop detection or closed-loop force feedback detection. Open-loop detection has a relatively simple structure, but the detection mode resonance peak is significant, the system bandwidth is limited by mechanical resonance characteristics, and linearity is prone to decrease when the angular velocity input is large or environmental conditions change. Closed-loop force feedback detection compensates for the detection mode displacement with feedback force, improving linearity and dynamic range; however, its performance depends on the coordinated design of modules such as loop filters, quantizers, analog-to-digital feedback, and demodulation filters.

[0004] Sigma-Delta closed-loop detection technology can effectively reduce in-band noise by transferring quantization noise to higher frequencies through oversampling and noise shaping. Meanwhile, the one-bit feedback digital-to-analog converter structure offers advantages such as high linearity and ease of implementation. However, if the loop order is low or the loop compensation design is inadequate, problems such as insufficient in-band noise suppression, significant noise peaks near the gyroscope resonant frequency, limited closed-loop bandwidth, and insufficient loop stability margin may still occur. Therefore, it is necessary to provide a fourth-order feedforward Sigma-Delta closed-loop detection circuit for MEMS gyroscopes. Summary of the Invention

[0005] The purpose of this invention is to address the problems of insufficient in-band noise suppression, obvious detection mode resonance peaks, limited closed-loop bandwidth, and high requirements for linearity and matching accuracy in multi-bit feedback digital-to-analog conversion of existing MEMS gyroscope detection circuits, and to provide a 4th-order feedforward Sigma-Delta closed-loop detection circuit for MEMS gyroscopes.

[0006] The technical solution to achieve the purpose of this invention is: a 4th-order feedforward Sigma-Delta closed-loop detection circuit for MEMS gyroscopes, comprising:

[0007] The signal front-end processing channel has its input end connected to the sensitive detection end of the MEMS gyroscope. It is used to amplify, suppress common-mode, and convert the weak detection signal output by the sensitive detection end to analog-to-digital, and output a discrete-time detection signal.

[0008] The digital conversion circuit, whose input is connected to the output of the signal front-end processing channel, is used to perform feedforward Sigma-Delta modulation on the discrete-time detection signal and output a 1-bit density modulated digital signal through a quantizer.

[0009] A closed-loop feedback path is provided, with its input end connected to the quantization output end of the digital conversion circuit and its output end connected to the MEMS gyroscope. It is used to convert the 1-bit density modulated digital signal into an analog feedback signal and apply feedback excitation to the MEMS gyroscope to form a closed-loop feedback path.

[0010] The signal demodulation output path is connected to the quantization output terminal of the digital conversion circuit and is used to demodulate and low-pass filter the 1-bit density modulated digital signal to output the angular velocity detection result.

[0011] Furthermore, the digital conversion circuit includes the following components connected in sequence:

[0012] The compensator is used to perform loop stability compensation and state scale tuning on the discrete-time detection signal to output a signal that satisfies closed-loop stability and digital operation scale.

[0013] A resonant circuit, whose center frequency corresponds to the resonant frequency of the MEMS gyroscope detection mode, is used to form a notch characteristic near the resonant frequency of the detection mode in order to suppress the resonant peak in the detection signal and achieve higher-order noise shaping.

[0014] A quantizer is used to quantize the signal output by the resonant circuit into the 1-bit density modulated digital signal.

[0015] Furthermore, the signal front-end processing channel includes:

[0016] A transimpedance amplifier is used to convert the two weak current signals output from the sensitive detection electrode of the MEMS gyroscope into voltage signals.

[0017] An instrumentation amplifier, whose input is connected to the output of the transimpedance amplifier, is used to differentially amplify the voltage signal and suppress common-mode interference;

[0018] A high-precision analog-to-digital converter is disposed between the instrumentation amplifier and the compensator of the digital conversion circuit. It is used to sample and quantize the output signal of the instrumentation amplifier and output the discrete-time detection signal to the compensator.

[0019] Furthermore, the closed-loop feedback path includes:

[0020] A 1-bit digital-to-analog converter is used to convert the 1-bit density modulated digital signal output by the quantizer into two reference levels, positive and negative.

[0021] An analog switch, whose control terminal is connected to the 1-bit density modulated digital signal, is used to switch the feedback voltage according to the state of the 1-bit density modulated digital signal, and apply the feedback voltage as the feedback excitation to the detection electrode of the MEMS gyroscope to apply the feedback excitation.

[0022] Furthermore, the signal demodulation output path includes:

[0023] A demodulator is used to introduce a reference signal that is in phase and frequency with the MEMS gyroscope driving mode, and to synchronously demodulate the 1-bit density modulated digital signal to shift the angular velocity-related components to a lower frequency.

[0024] A low-pass filter, connected to the output of the demodulator, is used to filter out high-frequency components, quantization noise, and out-of-band shaping noise after synchronous demodulation, and outputs an angular velocity detection result that is proportional to the input angular velocity.

[0025] Furthermore, the resonant circuit is a fourth-order feedforward resonant loop structure, namely a fourth-order feedforward Sigma-Delta structure, including a summation node, an integration unit, a delay unit, a state branch, a feedforward branch, and a feedback branch.

[0026] The state branch is used to form the state variables of the resonant loop;

[0027] The feedforward branch performs weighted processing on the input signal of the resonant circuit and the signals of each state variable, and then sums and superimposes them at the front end of the quantizer.

[0028] The feedback branch is used to feed the state variable back to the summing node.

[0029] Furthermore, the feedforward branch includes a first feedforward branch, a second feedforward branch, a third feedforward branch, and a fourth feedforward branch, which correspond to feedforward configuration coefficients a, b, c, and d, respectively;

[0030] The feedback branch includes a local feedback coefficient g2;

[0031] The feedforward configuration coefficients a, b, c, d and the local feedback coefficient g2 are all configured based on the mechanical structure parameters, circuit sampling frequency, target bandwidth and closed-loop stability margin of the MEMS gyroscope.

[0032] Furthermore, the quantizer is a one-bit quantizer, which converts the output of the resonant circuit into a binary sequence in the form of a high level or a low level through sign decision or threshold comparison. The pulse density of the binary sequence is used to characterize the closed-loop feedback quantity or input angular velocity information.

[0033] Furthermore, the digital conversion circuit is implemented by a programmable logic device, a digital signal processor, or an application-specific integrated circuit. The configuration coefficients of the compensator and resonant circuit inside it operate using a fixed-point digital arithmetic method, and the configuration coefficients are dynamically configured through registers.

[0034] Furthermore, the operating timing of the bit-to-digital converter and the analog switch is synchronized with the analog-to-digital conversion sampling clock in the signal front-end processing channel.

[0035] Compared with the prior art, the significant advantages of this invention are:

[0036] 1) This invention adopts a fourth-order feedforward Sigma-Delta modulation structure, which can perform high-order shaping of quantization noise, effectively reducing in-band noise and improving the detection signal-to-noise ratio.

[0037] 2) The present invention sets up a resonant circuit in the digital conversion circuit that corresponds to the resonant frequency of the MEMS gyroscope detection mode, which can form a notch characteristic near the frequency and reduce the response peak near the resonant frequency, thereby effectively improving the closed-loop bandwidth and stability.

[0038] 3) This invention uses a one-bit digital-to-analog converter and an analog switch to form a feedback path. The feedback circuit has a simple structure and high linearity, making it very suitable for on-chip integration of FPGA or application-specific integrated circuit (ASIC) and reducing hardware resource consumption.

[0039] 4) The compensator parameters of the present invention are configurable and can be flexibly adjusted according to the resonant frequency, quality factor and target bandwidth of different MEMS gyroscopes, which has good adaptability and engineering feasibility.

[0040] 5) This invention combines closed-loop feedback, 1-bit density modulation, synchronous demodulation, and low-pass filtering, which can output detection results proportional to angular velocity while maintaining the stability of the closed-loop of the MEMS gyroscope detection mode.

[0041] 6) This invention can be widely applied to MEMS gyroscope detection, inertial navigation, attitude measurement, and other weak resonant sensor closed-loop detection fields.

[0042] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0043] Figure 1This is a block diagram of a 4th-order feedforward Sigma-Delta closed-loop detection circuit for a MEMS gyroscope in one embodiment.

[0044] Figure 2 This is a schematic diagram of a MEMS gyroscope in one embodiment, where 10 is the sensitive detection electrode and 11 is the detection electrode.

[0045] Figure 3 This is a schematic diagram of a specific implementation structure of a 4th-order feedforward Sigma-Delta closed-loop detection circuit for a MEMS gyroscope in one embodiment. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0047] It should be noted that if the embodiments of the present invention involve descriptions such as "first" and "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" and "second" may explicitly or implicitly include at least one of those features. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0048] In one embodiment, combined Figures 1 to 3 A fourth-order feedforward Sigma-Delta closed-loop detection circuit for MEMS gyroscopes is proposed, including:

[0049] The signal front-end processing channel has its input end connected to the sensitive detection end of the MEMS gyroscope 1. It is used to amplify, suppress common-mode, and convert the weak detection signal output by the sensitive detection end to analog-to-digital, and output a discrete-time detection signal.

[0050] The digital conversion circuit 5 has its input terminal connected to the output terminal of the signal front-end processing channel, and is used to perform feedforward Sigma-Delta modulation on the discrete-time detection signal and output a 1-bit density modulated digital signal through a quantizer.

[0051] A closed-loop feedback path is provided, with its input end connected to the quantization output end of the digital conversion circuit and its output end connected to the MEMS gyroscope. It is used to convert the 1-bit density modulated digital signal into an analog feedback signal and apply feedback excitation to the MEMS gyroscope to form a closed-loop feedback path.

[0052] The signal demodulation output path is connected to the quantization output terminal of the digital conversion circuit and is used to demodulate and low-pass filter the 1-bit density modulated digital signal to output the angular velocity detection result.

[0053] Here, as Figure 2 As shown, the MEMS gyroscope includes multiple symmetrically arranged mass blocks, coupling beams, and a comb-type electrode structure. In one embodiment, the MEMS gyroscope is provided with a sensitive detection electrode 10 for outputting a detection signal related to the displacement of the detection mode, and a detection electrode 11 for inputting differential feedback excitation.

[0054] When MEMS gyroscope 1 is in drive mode and receives an external angular velocity input, the Coriolis effect causes a slight displacement in the detection mode that is related to the input angular velocity. This slight displacement changes the equivalent capacitance or charge distribution in the detection electrode region, thereby generating a detection signal related to the input angular velocity.

[0055] Furthermore, in one embodiment, the digital conversion circuit includes the following components connected in sequence:

[0056] Compensator 12 is used to perform loop stability compensation and state scale tuning on the discrete-time detection signal so as to output a signal that satisfies closed-loop stability and digital operation scale.

[0057] The resonant circuit 13, whose center frequency corresponds to the resonant frequency of the MEMS gyroscope detection mode, is used to form a notch characteristic near the resonant frequency of the detection mode in order to suppress the resonant peak in the detection signal and achieve higher-order noise shaping.

[0058] Quantizer 14 is used to quantize the signal output by the resonant circuit into the 1-bit density modulated digital signal.

[0059] Here, combined Figure 3 The detection signal from MEMS gyroscope 1 is input to transimpedance amplifier 2. Transimpedance amplifier 2 converts the current signal output from the detection electrode into a voltage signal. Instrumentation amplifier 3 differentially amplifies the voltage signal and suppresses common-mode interference. The amplified signal is then converted into a discrete-time detection signal by high-precision analog-to-digital converter 4 and sent to digital conversion circuit 5.

[0060] Preferably, in some embodiments, the compensator 12 can be implemented using a loop compensator Hcp to compensate the discrete-time detection signal output by the high-precision analog-to-digital converter 4, so that the detection loop has sufficient stability margin within the target bandwidth. The output of the compensator 12 is fed into the resonant circuit 13.

[0061] Furthermore, in one embodiment, the signal front-end processing channel includes:

[0062] Transimpedance amplifier 2 is used to convert the two weak current signals output from the MEMS gyroscope sensitive detection electrode into voltage signals.

[0063] Instrumentation amplifier 3, whose input terminal is connected to the output terminal of the transimpedance amplifier, is used to differentially amplify the voltage signal and suppress common-mode interference;

[0064] A high-precision analog-to-digital converter 4 is disposed between the instrumentation amplifier and the compensator of the digital conversion circuit, and is used to sample and quantize the output signal of the instrumentation amplifier and output the discrete-time detection signal to the compensator.

[0065] Furthermore, in one embodiment, the closed-loop feedback path includes:

[0066] A 1-bit digital-to-analog converter 6 is used to convert the 1-bit density modulated digital signal output by the quantizer into two reference levels, positive and negative.

[0067] Analog switch 7, whose control terminal is connected to the 1-bit density modulated digital signal, is used to switch the feedback voltage according to the state of the 1-bit density modulated digital signal, and apply the feedback voltage as the feedback excitation to the detection electrode of the MEMS gyroscope to apply the feedback excitation.

[0068] Furthermore, in one embodiment, the signal demodulation output path includes:

[0069] Demodulator 8 is used to introduce a reference signal that is in phase and frequency with the MEMS gyroscope driving mode, and synchronously demodulate the 1-bit density modulated digital signal to shift the angular velocity related components to a lower frequency.

[0070] The low-pass filter 9 is connected to the output of the demodulator and is used to filter out high-frequency components, quantization noise and out-of-band shaping noise after synchronous demodulation, and output angular velocity detection results that are proportional to the input angular velocity.

[0071] Furthermore, in one embodiment, the resonant circuit is a fourth-order feedforward resonant loop structure, namely a fourth-order feedforward Sigma-Delta structure, including a summation node, an integration unit, a delay unit, a state branch, a feedforward branch, and a feedback branch.

[0072] The state branch is used to form the state variables of the resonant loop;

[0073] The feedforward branch performs weighted processing on the input signal of the resonant circuit and the signals of each state variable, and then sums and superimposes them at the front end of the quantizer.

[0074] The feedback branch is used to feed the state variable back to the summing node.

[0075] Preferably, in some embodiments, the feedforward branch includes a first feedforward branch, a second feedforward branch, a third feedforward branch, and a fourth feedforward branch, which correspond to feedforward configuration coefficients a, b, c, and d, respectively.

[0076] The feedback branch includes a local feedback coefficient g2;

[0077] The feedforward configuration coefficients a, b, c, d and the local feedback coefficient g2 are all configured based on the mechanical structure parameters, circuit sampling frequency, target bandwidth and closed-loop stability margin of the MEMS gyroscope.

[0078] Here, the integrator, delay unit and local feedback branch of the resonant circuit 13 constitute a resonator, and its center frequency is set to the detection mode resonant frequency of the MEMS gyroscope 1, so that the digital conversion circuit 5 forms a notch or suppression effect near this frequency, thereby reducing the influence of the gyroscope resonance peak on the closed-loop detection result.

[0079] Furthermore, in one embodiment, the quantizer is a one-bit quantizer that converts the output of the resonant circuit into a binary sequence in the form of a high level or a low level through sign decision or threshold comparison. The pulse density of the binary sequence is used to characterize the closed-loop feedback or input angular velocity information.

[0080] Here, quantizer 14 is a one-bit quantizer, and its output is a binary sequence, namely a 1-bit density modulated digital signal Y. The average density of this 1-bit density modulated digital signal Y is related to the closed-loop feedback, and can reflect the input angular velocity information when the closed loop is stable.

[0081] One input to the 1-bit density modulated digital signal Y is a 1-bit digital-to-analog converter 6. The 1-bit digital-to-analog converter 6 outputs either positive or negative reference levels or two reference currents based on the binary sequence. An analog switch 7 applies feedback excitation to the feedback electrode of the MEMS gyroscope 1 according to the polarity of the reference level or reference current. This feedback excitation generates a feedback force in the opposite direction to the Coriolis force, keeping the detection mode of the MEMS gyroscope 1 in a near-zero displacement state, thereby forming a closed-loop detection.

[0082] Another input demodulator 8 to the 1-bit density modulated digital signal Y. Demodulator 8 can receive the reference signal V. ref Synchronous demodulation is performed to shift the angular velocity-related components to a lower frequency. Low-pass filter 9 filters out the high-frequency components, quantization noise, and out-of-band shaping noise after synchronous demodulation, outputting an angular velocity signal Ω that is proportional to the input angular velocity.

[0083] Furthermore, in one embodiment, the digital conversion circuit is implemented by a programmable logic device, a digital signal processor, or an application-specific integrated circuit, and the configuration coefficients of the compensator and resonant circuit inside it operate in a fixed-point digital arithmetic manner, and the configuration coefficients are dynamically configured through registers.

[0084] Furthermore, in one embodiment, the operating timing of the bit-to-digital converter and the analog switch is synchronized with the analog-to-digital conversion sampling clock in the signal front-end processing channel.

[0085] For example, the digital conversion circuit is implemented by an FPGA or an application-specific integrated circuit. In the FPGA implementation, the coefficients of the compensator 12 and the resonant circuit 13 can be represented by fixed-point numbers and can be configured by registers; the quantizer 14 can be implemented by sign decision or threshold comparison; the timing of the one-bit digital-to-analog converter 6 and the analog switch 7 can be synchronized with the sampling clock of the high-precision analog-to-digital converter 4.

[0086] In summary, the fourth-order feedforward Sigma-Delta closed-loop detection structure proposed in this invention combines the mechanical resonance characteristics of MEMS gyroscopes, digital resonance suppression structures, and one-bit feedback structures, achieving high in-band noise suppression capability and closed-loop bandwidth without significantly increasing the complexity of analog circuits.

[0087] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention without departing from its spirit and scope should be included within the protection scope of the present invention.

Claims

1. A fourth-order feedforward Sigma-Delta closed-loop detection circuit for a MEMS gyroscope, characterized in that, include: The signal front-end processing channel has its input end connected to the sensitive detection end of the MEMS gyroscope. It is used to amplify, suppress common-mode, and convert the weak detection signal output by the sensitive detection end to analog-to-digital, and output a discrete-time detection signal. The digital conversion circuit, whose input is connected to the output of the signal front-end processing channel, is used to perform feedforward Sigma-Delta modulation on the discrete-time detection signal and output a 1-bit density modulated digital signal through a quantizer. A closed-loop feedback path is provided, with its input end connected to the quantization output end of the digital conversion circuit and its output end connected to the MEMS gyroscope. It is used to convert the 1-bit density modulated digital signal into an analog feedback signal and apply feedback excitation to the MEMS gyroscope to form a closed-loop feedback path. The signal demodulation output path is connected to the quantization output terminal of the digital conversion circuit and is used to demodulate and low-pass filter the 1-bit density modulated digital signal to output the angular velocity detection result.

2. The MEMS gyroscope fourth-order feedforward Sigma-Delta closed-loop detection circuit according to claim 1, characterized in that, The digital conversion circuit comprises the following components connected in sequence: The compensator is used to perform loop stability compensation and state scale tuning on the discrete-time detection signal to output a signal that satisfies closed-loop stability and digital operation scale. A resonant circuit, whose center frequency corresponds to the resonant frequency of the MEMS gyroscope detection mode, is used to form a notch characteristic near the resonant frequency of the detection mode in order to suppress the resonant peak in the detection signal and achieve higher-order noise shaping. A quantizer is used to quantize the signal output by the resonant circuit into the 1-bit density modulated digital signal.

3. The MEMS gyroscope fourth-order feedforward Sigma-Delta closed-loop detection circuit according to claim 2, characterized in that, The signal front-end processing channel includes: A transimpedance amplifier is used to convert the two weak current signals output from the sensitive detection electrode of the MEMS gyroscope into voltage signals. An instrumentation amplifier, whose input is connected to the output of the transimpedance amplifier, is used to differentially amplify the voltage signal and suppress common-mode interference; A high-precision analog-to-digital converter is disposed between the instrumentation amplifier and the compensator of the digital conversion circuit. It is used to sample and quantize the output signal of the instrumentation amplifier and output the discrete-time detection signal to the compensator.

4. The MEMS gyroscope fourth-order feedforward Sigma-Delta closed-loop detection circuit according to claim 2, characterized in that, The closed-loop feedback path includes: A 1-bit digital-to-analog converter is used to convert the 1-bit density modulated digital signal output by the quantizer into two reference levels, positive and negative. An analog switch, whose control terminal is connected to the 1-bit density modulated digital signal, is used to switch the feedback voltage according to the state of the 1-bit density modulated digital signal, and apply the feedback voltage as the feedback excitation to the detection electrode of the MEMS gyroscope to apply the feedback excitation.

5. The MEMS gyroscope fourth-order feedforward Sigma-Delta closed-loop detection circuit according to claim 2, characterized in that, The signal demodulation output path includes: A demodulator is used to introduce a reference signal that is in phase and frequency with the MEMS gyroscope driving mode, and to synchronously demodulate the 1-bit density modulated digital signal to shift the angular velocity-related components to a lower frequency. A low-pass filter, connected to the output of the demodulator, is used to filter out high-frequency components, quantization noise, and out-of-band shaping noise after synchronous demodulation, and outputs an angular velocity detection result that is proportional to the input angular velocity.

6. The MEMS gyroscope fourth-order feedforward Sigma-Delta closed-loop detection circuit according to claim 2, characterized in that, The resonant circuit is a fourth-order feedforward resonant loop structure, namely a fourth-order feedforward Sigma-Delta structure, including a summation node, an integration unit, a delay unit, a state branch, a feedforward branch, and a feedback branch. The state branch is used to form the state variables of the resonant loop; The feedforward branch performs weighted processing on the input signal of the resonant circuit and the signals of each state variable, and then sums and superimposes them at the front end of the quantizer. The feedback branch is used to feed the state variable back to the summing node.

7. The MEMS gyroscope fourth-order feedforward Sigma-Delta closed-loop detection circuit according to claim 6, characterized in that, The feedforward branch includes a first feedforward branch, a second feedforward branch, a third feedforward branch, and a fourth feedforward branch, which correspond to feedforward configuration coefficients a, b, c, and d, respectively. The feedback branch includes a local feedback coefficient g2; The feedforward configuration coefficients a, b, c, d and the local feedback coefficient g2 are all configured based on the mechanical structure parameters, circuit sampling frequency, target bandwidth and closed-loop stability margin of the MEMS gyroscope.

8. The MEMS gyroscope fourth-order feedforward Sigma-Delta closed-loop detection circuit according to claim 2, characterized in that, The quantizer is a one-bit quantizer, which converts the output of the resonant circuit into a binary sequence in the form of a high level or a low level through sign decision or threshold comparison. The pulse density of the binary sequence is used to characterize the closed-loop feedback or input angular velocity information.

9. The MEMS gyroscope fourth-order feedforward Sigma-Delta closed-loop detection circuit according to any one of claims 2 to 8, characterized in that, The digital conversion circuit is implemented by a programmable logic device, a digital signal processor, or an application-specific integrated circuit. The configuration coefficients of the compensator and resonant circuit inside it operate using fixed-point digital arithmetic, and the configuration coefficients are dynamically configured through registers.

10. The MEMS gyroscope fourth-order feedforward Sigma-Delta closed-loop detection circuit according to claim 4, characterized in that, The operating timing of the bit-to-digital converter and the analog switch is synchronized with the analog-to-digital conversion sampling clock in the signal front-end processing channel.

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