Temperature measurement method and circuit based on MEMS driving signal intensity Q value detection

Abstract

The invention provides a temperature measurement method based on MEMS driving signal intensity Q value detection, and the method comprises the steps: replacing a PGA in a conventional driving loop with a DPGA, and adding a digital-to-analog converter ADC between the DPGA and a PI controller; a resonance maintaining loop is formed between the MEMS resonator and the trans-impedance amplifiers TIA and DPGA; after a TIA output signal passes through a rectifier, the TIA output signal is subtracted from a reference voltage, and then a direct-current component is extracted through a PI controller; a direct current signal output by the PI controller is quantized by the ADC and then is used for controlling the gain of the DPGA, so that the constant amplitude of a resonance signal passing through the MEMS resonator is maintained; meanwhile, the gain calculation module is used for calculating gains of the MEMS resonator and the TIA so as to obtain a Q value of the MEMS resonator; and on the basis that the Q value is inversely proportional to the temperature, the temperature information of the MEMS resonator is obtained in real time through the signal quantized by the ADC.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit design technology, and more specifically, to a temperature measurement method and circuit based on the detection of the Q value of MEMS driving signal intensity. Background Technology

[0002] Resonant accelerometers (SOAs) represent a class of high-precision microelectromechanical systems (MEMS) accelerometers with unique time-modulation characteristics. These devices combine high sensitivity with excellent long-term stability and have significant miniaturization potential, making them a promising alternative to low-cost MEMS capacitive accelerometers and traditional quartz bending accelerometers, thus enabling performance breakthroughs in fields such as high-precision positioning and inertial navigation.

[0003] However, key bias stability metrics remain limited by the characteristics of silicon and MEMS packaging, resulting in performance gaps compared to quartz accelerometers. One representative problem is temperature drift; temperature fluctuations cause resonant frequency drift and compromise the long-term bias stability of MEMS oscillators. Temperature-dependent stress and the temperature coefficient of silicon are the primary causes of this problem. Currently, the common approach to addressing temperature drift at the circuit system level is to compensate by fitting the temperature drift of the on-chip temperature measured by a thermometer to the frequency.

[0004] To address this problem, various solutions have been proposed in domestic and international research. The literature HK Lee, R. Melamud, B. Kim, MA Hopcroft, JC Salvia and TW Kenny, "Electrostatic Tuning to Achieve Higher Stability Microelectromechanical Composite Resonators," in Journal of Microelectromechanical Systems, vol. 20, no. 6, pp. 1355-1365, Dec. 2011, doi: 10.1109 / JMEMS.2011.2168083, proposes a method of placing a temperature sensor within the MEMS resonator to obtain the internal temperature of the resonator, thereby achieving temperature compensation. The literature D. Liu et al., "In-Situ Compensation on Temperature Coefficient of the Scale Factor for a Single-Axis Nano-g Force-Balance MEMS Accelerometer," in IEEE Sensors Journal, vol. 21, no. 18, pp. 19872-19880, 15 Sept. 15, 2021, doi: 10.1109 / JSEN.2021.3098797, proposes integrating a thermistor into the MEMS resonator and utilizing the temperature-dependent resistance of the thermistor to build an external compensation circuit. However, both of these methods struggle to perform in-situ temperature measurements under dynamic temperature gradients, as the in-situ temperature always lags behind the probe temperature, resulting in hysteresis in the temperature curve. The quality factor of a resonator has been shown to be an ideal parameter for temperature indicators, and it is close to zero in relation to MEMS structures, as in the literature KIM B, HOPCROFT MA, CANDLER RN, et al. Temperature dependence of quality factor in MEMSresonators [J]. Journal of Microelectromechanical Systems, 2008, 17(3): 755-66.An amplitude modulation (AM) method based on resonator amplification factor measurement has been used for real-time quality factor monitoring, as seen in the literature HOPCROFT MA, AGARWAL M, PARK KK, et al. Temperature compensation of a MEMSresonator using quality factor as a thermometer; procedures of the 19th IEEE International Conference on Micro ElectroMechanical Systems (MEMS 2006), Istanbul, TURKEY, F Jan 22-26, 2006 [C]. 2006. However, the amplitude modulation (AM) method is affected by changes in circuit gain, making it difficult to achieve high-precision quality factor measurement. The 2018 paper by Y. Wang et al., "AMEMS Resonant Accelerometer With High Performance of Temperature Based on Electrostatic Spring Softening and Continuous Ring-Down Technique," in IEEE Sensors Journal, vol. 18, no. 17, pp. 7023-7031, 1 Sept. 1, 2018, doi:10.1109 / JSEN.2018.2852647, proposes a method to address this problem. It employs a continuous excitation-decrease technique to monitor the quality factor in real time, using it as a virtual thermometer. This reduces measurement lag and improves the accuracy of temperature compensation. However, the continuous excitation-decrease method causes the amplitude of the signal in the resonator drive loop to constantly change, ultimately generating low-frequency noise through amplitude-stiffness coupling effects, making it difficult to achieve real-time quality factor measurement under high-precision conditions. Therefore, high-precision real-time quality factor monitoring remains a key challenge for temperature compensation in resonant MEMS oscillators.

[0005] Currently, no descriptions or reports of technologies similar to this invention have been found, and no similar information has been collected domestically or internationally. Summary of the Invention

[0006] To address the aforementioned shortcomings in the prior art, this invention provides a temperature measurement method and circuit based on the detection of the Q value of MEMS driving signal intensity.

[0007] According to one aspect of the present invention, a temperature measurement method based on the detection of the Q-value of a MEMS driving signal is provided, comprising: The PGA in the traditional drive loop is replaced with a DPGA, and a digital-to-analog converter (ADC) is added between the DPGA and the PI controller. The MEMS resonator forms a resonant sustaining loop with the transimpedance amplifier (TIA) and the DPGA; the TIA output signal, after being rectified, is compared with the reference voltage. Subtract them, and then extract the DC component using a PI controller; The DC signal output by the PI controller is quantized by the ADC and used to control the gain of the DPGA, thereby maintaining a constant amplitude of the resonant signal through the MEMS resonator; at the same time, it is used to calculate the gain of the MEMS resonator and TIA, and then obtain the Q value of the MEMS resonator. Based on the inverse relationship between the Q value and temperature, the temperature information of the MEMS resonator is obtained in real time through the signal quantized by the ADC.

[0008] Preferably, a notch filter is further provided between the ADC and the DPGA, and the notch filter is used to reduce the noise generated by the ADC quantization.

[0009] According to another aspect of the present invention, a silicon resonator in-situ temperature detection circuit based on drive power quantization is provided, comprising: a conventional drive loop; wherein, in the conventional drive loop, a DPGA is used instead of a PGA, and a digital-to-analog converter (ADC) is inserted between the DPGA and the PI controller; wherein: The MEMS resonator forms a resonant sustaining loop with the transimpedance amplifier (TIA) and the DPGA; the TIA output signal, after being rectified, is compared with the reference voltage. Subtract them, and then extract the DC component using a PI controller; The DC signal output by the PI controller is quantized by the ADC and used to control the gain of the DPGA, thereby maintaining a constant amplitude of the resonant signal through the MEMS resonator; at the same time, it is used to calculate the gain of the MEMS resonator and TIA, and then obtain the Q value of the MEMS resonator. Based on the inverse relationship between the Q value and temperature, the temperature information of the MEMS resonator is obtained in real time through the signal quantized by the ADC.

[0010] Preferably, a notch filter is further provided between the ADC and the DPGA, and the notch filter is used to reduce the noise generated by the ADC quantization.

[0011] By adopting the above technical solution, the present invention has at least one of the following beneficial effects compared with the prior art: The temperature measurement method and circuit based on MEMS drive signal strength Q-value detection provided by this invention can significantly reduce the hysteresis effect during temperature measurement by measuring the temperature of MEMS resonators through Q-value, and is more advantageous than the solution using temperature sensor and thermistor.

[0012] The temperature measurement method and circuit based on MEMS driving signal strength Q-value detection provided by this invention effectively avoids noise of the amplitude signal coupling into the frequency measurement module through the amplitude stiffness effect. The signal controlling the DPGA is quantized by an ADC to obtain the digital information of the DPGA gain, thereby calculating the Q-value of the MEMS resonator structure and ultimately obtaining the low-hysteresis temperature information in the MEMS resonator.

[0013] The temperature measurement method and circuit based on MEMS driving signal intensity Q-value detection provided by this invention can also include a notch filter at the ADC back-end. Its main function is to filter the ADC output signal to avoid it from being filtered at frequencies of 0.5 and 0.5. Noise aliasing occurs when the drive signals are multiplied.

[0014] The temperature measurement method and circuit based on MEMS drive signal strength Q-value detection provided by this invention obtains low-hysteresis temperature information on the MEMS resonator by measuring the Q-value of the MEMS resonator in real time. Simultaneously, it maintains the amplitude of the resonant signal constant to avoid introducing additional low-frequency noise through amplitude-stiffness coupling effects. Furthermore, by utilizing the mechanically sensitive structure of the MEMS resonator itself and the order of the loop proportional-integral (PI) controller, high-order noise shaping is achieved when reading the Q-value, resulting in high-precision temperature information. Attached Figure Description

[0015] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the in-situ temperature detection circuit and detection method of silicon resonator based on drive power quantization in a preferred embodiment of the present invention.

[0016] Figure 2 This is a circuit implementation diagram of DPGA in a preferred embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram illustrating the derivation and principle explanation of calculating the Q value of a MEMS resonator and obtaining the temperature information of the MEMS resonator in a preferred embodiment of the present invention. Detailed Implementation

[0018] The embodiments of the present invention are described in detail below: These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

[0019] In existing technologies, traditional temperature measurement methods, such as sensing information from MEMS resonators using temperature sensors and thermistors, suffer from an unavoidable hysteresis phenomenon between the obtained temperature information and the actual temperature information within the MEMS resonator, hindering temperature compensation for the MEMS resonator. Furthermore, traditional Q-value measurement methods are affected by changes in circuit gain and low-frequency noise caused by variations in the amplitude of the driving signal.

[0020] To address the aforementioned problems, one embodiment of the present invention provides a temperature measurement method based on the Q-value detection of MEMS driving signal intensity, belonging to a MEMS resonant accelerometer interface integration technology. This method aims to obtain low-hysteresis temperature information on the MEMS resonator by measuring its Q-value in real time, while maintaining the amplitude of the resonant signal unchanged to avoid introducing additional low-frequency noise through amplitude-stiffness coupling effects. Furthermore, by utilizing the mechanically sensitive structure of the MEMS resonator itself and the order of the loop proportional-integral (PI) controller, high-order noise shaping is achieved when reading the Q-value, resulting in high-precision temperature information.

[0021] Specifically, such as Figure 1 As shown, the temperature measurement method based on MEMS drive signal intensity Q-value detection provided in this embodiment may include: The PGA in the traditional drive loop is replaced with a DPGA, and a digital-to-analog converter (ADC) is added between the DPGA and the PI controller. The MEMS resonator forms a resonant sustaining loop with the transimpedance amplifier (TIA) and the DPGA; the TIA output signal, after being rectified, is compared with the reference voltage. Subtract them, and then extract the DC component using a PI controller; The DC signal output by the PI controller is quantized by the ADC and used to control the gain of the DPGA, thereby maintaining a constant amplitude of the resonant signal through the MEMS resonator; at the same time, it is used to calculate the gain of the MEMS resonator and TIA, and then obtain the Q value of the MEMS resonator. Based on the inverse relationship between the Q value and temperature, the temperature information of the MEMS resonator is obtained in real time through the signal quantized by the ADC.

[0022] In some preferred embodiments, a notch filter is further provided between the ADC and the DPGA, the notch filter being used to reduce the quantization noise of the ADC at frequencies of . The influence of the resonant signal.

[0023] In some preferred embodiments, the notch filter has a resonant frequency of [value missing] in the ADC-quantized signal. The information at the point is filtered to prevent noise from aliasing into the drive loop and affecting the resonant sinusoidal signal of the MEMS resonator.

[0024] In some preferred embodiments, the notch filter is implemented in any of the following ways: A second-order IIR structure is adopted, and zero-pole pairs are set at the target frequency to achieve narrowband deep suppression with low computational cost; FIR band-stop filters can be designed using window functions or frequency sampling methods to achieve good linear phase while ensuring notch filtering effect. A comb-shaped FIR structure is constructed, and a periodic notch is formed by fixing the tap interval, thereby effectively suppressing a single frequency point under specific conditions; An adaptive notch filtering method is employed, using the LMS or RLS algorithm within the IIR or FIR framework to adjust parameters online in order to track interference signals with slowly drifting frequencies.

[0025] In some preferred embodiments, such as Figure 2 As shown, the DPGA may further include an amplifier and a capacitor array. The input terminal of the operational amplifier is connected to a controllable input capacitor array, and a capacitor array is also connected across the input and output terminals. The ratio of the cross-connect capacitor to the input capacitor determines the gain of the DPGA. The quantized signal from the ADC is used to control the input capacitor array. The amplifier gain of the DPGA can be programmably controlled by changing the capacitance of the input capacitor array.

[0026] In some preferred embodiments, controlling the gain of the DPGA to maintain a constant amplitude of the resonant signal through the MEMS resonator may further include: The frequency information of the sinusoidal signal in the drive loop is extracted using a frequency-to-digital converter (FDC); where: FDC outputs signals through TIA Measurements are performed to obtain the frequency information of the corresponding MEMS resonator. By calculating the difference in frequency information, the frequency difference used to reflect the magnitude of acceleration is obtained.

[0027] In some preferred embodiments, such as Figure 3As shown, obtaining the Q value of the MEMS resonator may further include: The transfer function of the MEMS resonator is: In the formula, This represents the transfer function of a MEMS resonator. It is a constant related to the MEMS sensor itself. Indicates the resonant frequency. For the complex frequency variable in the Laplace transform, The Q value of the MEMS resonator; The signal quantized by the ADC The value is the product of the MEMS resonator gain and the TIA gain, and its expression is: In the formula, This indicates the driving voltage of the MEMS resonator. This indicates the output voltage of the TIA module. Indicates the gain of TIA; in, and All are constant values, and at the same time and resonant frequency This is also known, so the signal is output through the ADC. The value can be used to calculate the Q value of the MEMS resonator in real time.

[0028] In some preferred embodiments, such as Figure 3 As shown, the method of obtaining the temperature information of the MEMS resonator in real time through the quantized signal of the ADC based on the inverse relationship between the Q value and temperature may further include: Based on the inverse relationship between the Q value of a MEMS resonator and temperature, we can obtain: In the formula, This indicates the Q value of the MEMS resonator. This indicates the temperature of the MEMS resonator structure. This indicates that the two variables are directly proportional. Output signal via ADC It can acquire the temperature information of the MEMS resonator in real time.

[0029] Based on the same inventive concept, an embodiment of the present invention also provides a silicon resonator in-situ temperature detection circuit based on drive power quantization.

[0030] Specifically, such as Figure 1As shown, the temperature measurement circuit based on MEMS drive signal strength Q-value detection provided in this embodiment may include: a conventional drive loop; in the conventional drive loop, a DPGA is used instead of a PGA, and a digital-to-analog converter (ADC) is inserted between the DPGA and the PI controller; wherein: The MEMS resonator forms a resonant sustaining loop with the transimpedance amplifier (TIA) and the DPGA; the TIA output signal, after being rectified, is compared with the reference voltage. Subtract them, and then extract the DC component using a PI controller; The DC signal output by the PI controller is quantized by the ADC and used to control the gain of the DPGA, thereby maintaining a constant amplitude of the resonant signal through the MEMS resonator; at the same time, it is used to calculate the gain of the MEMS resonator and TIA, and then obtain the Q value of the MEMS resonator. Based on the inverse relationship between the Q value and temperature, the temperature information of the MEMS resonator is obtained in real time through the signal quantized by the ADC.

[0031] In some preferred embodiments, in the above circuit, a notch filter is further provided between the ADC and the DPGA, and the notch filter is used to reduce the noise generated by the ADC quantization.

[0032] It should be noted that the steps in the method provided by the present invention can be implemented using corresponding modules, devices, units, etc. in the system. Those skilled in the art can refer to the technical solution of the method to realize the composition of the system. That is, the embodiments in the method can be understood as preferred examples for building the system, and will not be elaborated here.

[0033] The technical solution provided by the above embodiments of the present invention will be further described in detail below with reference to a specific application example.

[0034] In this specific application example, a dedicated temperature measurement circuit architecture for the MEMS driving strength Q value is as follows: Figure 1 As shown, the black portion represents a module of the traditional drive loop. The MEMS resonator can be a differential structure or a single-ended output structure. If the MEMS resonator structure is a single-ended output, only one channel is needed. This section uses a differential structure as an example for further explanation. When the MEMS resonator senses acceleration, the resonant frequencies of MEMS resonator-1 in channel 1 and MEMS resonator-2 in channel 2 will change differentially in opposite directions, with a frequency difference... It can be used to measure the magnitude of acceleration. Channels 1 and 2 can read the frequencies at both ends of the differential signal, thus obtaining frequency difference information. A single MEMS resonator forms a resonant sustaining loop with the transgroup amplifier (TIA) and the gain programmable amplifier (DPGA), and maintains the amplitude of the resonant signal passing through the MEMS resonator stable under the control of the rectifier, PI controller, and analog-to-digital converter (ADC). The TIA output signal is converted into a digital signal containing frequency information by the frequency-to-digital converter (FDC). and The digital signal output by the ADC and While controlling the DPGA gain to maintain stable loop resonant signal amplitude, it is also possible to characterize the Q-value of the MEMS resonator, thereby obtaining low-hysteresis temperature information within the MEMS resonator structure. A notch filter is connected after the ADC module to process the ADC quantization information. The information at the point is filtered to prevent noise from aliasing into the drive loop and affecting the resonant sinusoidal signal of the resonator.

[0035] In this specific application example, the implementation of each module is as follows: Microelectromechanical systems (MEMS) structure: Using a resonant MEMS structure, acceleration information is converted into resonant frequency information.

[0036] Transimpedance Amplifier (TIA): The function of the TIA is to amplify the current output from the MEMS resonator into a voltage for measurement and feedback control. The TIA needs to be temperature-insensitive, and its gain needs to be constant to allow for real-time Q-value measurement. The TIA also needs to ensure that the input current signal and the output voltage signal are in phase, enabling the drive loop to function correctly.

[0037] Rectifier: The function of a rectifier is to extract the amplitude information of a signal, so that the loop can control the amplitude of the signal.

[0038] Subtractor: A subtractor converts a signal into a subtractor. and Subtraction. There are several ways to achieve voltage subtraction. It can be done using a proportional amplifier, or by first converting the voltage to current and then subtracting the current.

[0039] Proportional-Integral (PI) Controller: The function of a PI controller is to convert the input signal into a proportional-integral (PI) controller. and The difference is filtered to extract the DC signal, which is then used for ADC quantization. The PI controller here, because it has a low-pass filtering function, can also be called a low-pass filter. The order of the PI controller can be varied as needed, as long as loop stability is ensured.

[0040] Analog-to-Digital Converter (ADC): The role of the ADC in the loop is to quantize the DC information from the PI controller. This serves two purposes: firstly, it controls the DPGA to achieve amplitude control; secondly, the quantization result of the ADC... This can be used to quantify the gain of MEMS resonators and TIAs, thereby calculating the Q value of the MEMS resonator. The quantization result of the Q value... Thanks to the shaping effect of the MEMS mechanical sensing structure and the PI controller, the ADC bit depth does not need to be very high to achieve fairly high quantization accuracy. The ADC can use the oscillation frequency of the MEMS resonator as the sampling clock. Alternatively, an external clock can be used for sampling.

[0041] Notch filter: The notch filter here is an optional module. Its main function is to reduce the impact of ADC quantization noise on the drive loop signal. The notch filter must be sampled using the oscillation frequency of the MEMS resonator. Since the ADC quantization noise affects the drive loop in a multiplicative manner, the quantization noise at a frequency of... When driving a sinusoidal signal, modulation is performed first. The quantization noise contains a frequency of... The signal components will be modulated, thus affecting the sinusoidal signal in the drive loop. Therefore, the notch filter here modulates the signal... Filtering can reduce the impact of ADC quantization noise on the drive loop and ensure the quality of the drive signal. Digital notch filters can be implemented in several ways: a second-order IIR (biquad) structure can be used, setting zero-pole pairs at the target frequency to achieve narrowband deep suppression with low computational cost; an FIR band-stop filter can be designed using window functions or frequency sampling methods to obtain good linear phase while ensuring notch effect; a comb-shaped FIR structure can be constructed, forming periodic notches by fixing the tap interval, thereby effectively suppressing a single frequency under specific conditions; in addition, an adaptive notch method can be used, using LMS or RLS algorithms to adjust parameters online within the IIR or FIR framework to track slowly drifting interference signals.

[0042] Digitally Controlled Gain Programmable Amplifier (DPGA): The function of a DPGA is to enable control of the loop gain via digital signals. Digital signal control is necessary because the previous stage, using an ADC, has already converted the analog signal to a digital signal, so direct digital control is required. The loop gain control is used in conjunction with an amplitude control loop to control the amplitude of the drive signal, thereby preventing amplitude noise from interfering with frequency information through stiffness amplitude effects. Figure 2This illustrates the implementation of a DPGA in a circuit. The digital signal output from the notch filter controls the input capacitor of the amplifier, thereby changing the amplifier's gain and achieving a programmable gain amplifier. To change the number of bits in the DPGA control signal, the amplifier's input capacitors can be designed as a sparser or denser capacitor array to facilitate digital signal control.

[0043] Frequency-to-Digital Converter (FDC): The function of the FDC is to extract the frequency information of the sinusoidal signal in the drive loop. The FDC outputs the signal through the TIA. Measurements are performed to obtain frequency information, and the magnitude of acceleration is obtained by calculating the frequency difference between the two channels. The FDC here needs to be able to quantize the frequency of the sinusoidal signal, and can also increase the signal-to-noise ratio of the frequency measurement by using a PLL for frequency multiplication. Figure 1 As shown.

[0044] like Figure 3 The diagram illustrates the model derivation and principle explanation of this invention, and illustrates the small-signal model of the resonant loop. The transfer function of the MEMS structure is: from Figure 3 The digital control signal of DPGA can be derived from the small-signal model. The value is the product of the MEMS resonator gain and the TIA gain, and its expression is: Among them and All are constant values, and the resonant frequency is constant. This is also known, so the digital signal output by the ADC module can be used. The Q-value of the MEMS resonator is calculated in real time. Furthermore, the Q-value of the MEMS resonator is inversely proportional to temperature, which can be obtained as follows: Therefore, this circuit can achieve signal output via ADC. This method can acquire temperature information of MEMS resonators in real time, and because it is not limited by the physical distance of the sensor during measurement, it has less temperature hysteresis compared to traditional methods.

[0045] The temperature measurement method and circuit based on MEMS drive signal strength Q-value detection provided in the above embodiments of the present invention replace the traditional programmable gain amplifier (PGA) in the drive loop with a digitally controlled programmable gain amplifier (DPGA) and add an analog-to-digital converter (ADC) module. This allows the gain of the MEMS structure and the transimpedance amplifier (TIA) to be obtained through the signal output by the ADC, thereby calculating the Q-value of the resonator in real time. The signal generated by the MEMS, after passing through the transimpedance amplifier (TIA), will first pass through a rectifier and then be compared with a voltage reference. After subtraction, the DC component is extracted by a PI controller. This DC component controls the gain of the digitally controlled programmable gain amplifier (DPGA), thereby maintaining the amplitude of the loop oscillation signal. In this embodiment, after quantizing the DC signal output by the PI controller, the gain of the MEMS structure and TIA can be obtained based on the relationship between the gain and the control word in the DPGA, thus further calculating the Q value of the MEMS resonator.

[0046] The temperature measurement method and circuit based on MEMS drive signal strength Q-value detection provided in the above embodiments of the present invention significantly reduce the hysteresis effect during temperature measurement by measuring the temperature of the MEMS resonator through Q-value measurement, which is more advantageous than the scheme using temperature sensors and thermistors. Compared with existing Q-value measurement methods, this embodiment does not suffer from the problem of circuit gain changes due to the use of amplitude modulation (AM) methods, and does not cause changes in the amplitude of the drive signal, thereby effectively avoiding noise of the amplitude signal coupled into the frequency measurement module through the amplitude stiffness effect. The signal controlling the DPGA is quantized by the ADC to obtain the digital information of the DPGA gain, so as to calculate the Q-value of the MEMS resonator structure, and then obtain the low-hysteresis temperature information of the MEMS resonator. The notch filter after the ADC is optional, and its main function is to filter the ADC output signal. The frequency information is filtered to avoid it being at the same frequency as the frequency. Noise aliasing occurs when the drive signals are multiplied.

[0047] Any matters not covered in the above embodiments of the present invention are well-known in the art.

[0048] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A temperature measurement method based on the detection of Q-value of MEMS driving signal intensity, characterized in that, include: The PGA in the traditional drive loop is replaced with a DPGA, and a digital-to-analog converter (ADC) is added between the DPGA and the PI controller. The MEMS resonator forms a resonant sustaining loop with the transimpedance amplifier (TIA) and the DPGA; the TIA output signal, after being rectified, is compared with the reference voltage. Subtract them, and then extract the DC component using a PI controller; The DC signal output by the PI controller is quantized by the ADC and used to control the gain of the DPGA, thereby maintaining the constant amplitude of the resonant signal through the MEMS resonator. Simultaneously, it is used to calculate the gain of the MEMS resonator and TIA, and then obtain the Q value of the MEMS resonator; Based on the inverse relationship between the Q value and temperature, the temperature information of the MEMS resonator is obtained in real time through the signal quantized by the ADC.

2. The temperature measurement method based on MEMS driving signal intensity Q-value detection according to claim 1, characterized in that, A notch filter is also provided between the ADC and the DPGA, and the notch filter is used to reduce the noise generated by the ADC quantization.

3. The temperature measurement method based on MEMS driving signal intensity Q-value detection according to claim 2, characterized in that, The notch filter, in the signal quantized by the ADC, has a resonant frequency of... The information at the point is filtered to prevent noise from aliasing into the drive loop and affecting the resonant sinusoidal signal of the MEMS resonator.

4. The temperature measurement method based on MEMS driving signal intensity Q-value detection according to claim 2, characterized in that, The notch filter can be implemented in any of the following ways: A second-order IIR structure is adopted, and zero-pole pairs are set at the target frequency to achieve narrowband deep suppression with low computational cost; FIR band-stop filters are designed using window functions or frequency sampling methods to achieve linear phase while ensuring notch filtering effect. A comb-shaped FIR structure is constructed, and a periodic notch is formed by fixing the tap interval, thereby suppressing a single frequency point under specific conditions; An adaptive notch filtering method is employed, using the LMS or RLS algorithm within the IIR or FIR framework to adjust parameters online in order to track interference signals with slowly drifting frequencies.

5. The temperature measurement method based on MEMS driving signal intensity Q-value detection according to claim 1, characterized in that, The DPGA includes an operational amplifier and a capacitor array; wherein, the input terminal of the operational amplifier is connected to a controllable input capacitor array, and another capacitor array is connected across the input terminal and the output terminal; the quantized signal of the ADC is used to control the input capacitor array. The ratio of the bridging capacitor to the input capacitor determines the gain of the DPGA. By changing the size of the input capacitor array, the amplifier gain of the DPGA can be programmably controlled.

6. The temperature measurement method based on MEMS driving signal intensity Q-value detection according to claim 1, characterized in that, Controlling the gain of the DPGA to maintain a constant amplitude of the resonant signal through the MEMS resonator includes: The frequency information of the sinusoidal signal in the drive loop is extracted using a frequency-to-digital converter (FDC); where: FDC outputs signals through TIA Measurements are performed to obtain the frequency information of the corresponding MEMS resonator. By calculating the difference in frequency information, the frequency difference used to reflect the magnitude of acceleration is obtained.

7. The temperature measurement method based on MEMS driving signal intensity Q-value detection according to claim 1, characterized in that, The process of obtaining the Q value of the MEMS resonator includes: Transfer function of MEMS resonators for: In the formula, It is a constant related to the MEMS sensor itself. Indicates the resonant frequency. For the complex frequency variable in the Laplace transform, The Q value of the MEMS resonator; ADC quantized signal The value is the product of the MEMS resonator gain and the TIA gain, and its expression is: In the formula, This represents the driving voltage of the MEMS resonator. This indicates the output voltage of the TIA module. Indicates the gain of TIA; in, and All are constant values, and at the same time and resonant frequency This is also known, so the signal is output through the ADC. The value can be used to calculate the Q value of the MEMS resonator in real time.

8. The temperature measurement method based on MEMS driving signal intensity Q-value detection according to claim 1, characterized in that, The method of acquiring the temperature information of the MEMS resonator in real time through the ADC-quantized signal, based on the inverse relationship between the Q value and temperature, includes: Based on the inverse relationship between the Q value of a MEMS resonator and temperature, we can obtain: In the formula, This indicates the Q value of the MEMS resonator. This indicates the temperature of the MEMS resonator structure. This indicates that the two variables are directly proportional. Output signal via ADC It can acquire the temperature information of the MEMS resonator in real time.

9. A silicon resonator in-situ temperature detection circuit based on drive power quantization, comprising: Traditional drive loop; characterized in that, in the traditional drive loop, a DPGA is used instead of a PGA, and a digital-to-analog converter (ADC) is inserted between the DPGA and the PI controller; wherein: The MEMS resonator forms a resonant sustaining loop with the transimpedance amplifier (TIA) and the DPGA; the TIA output signal, after being rectified, is compared with the reference voltage. Subtract them, and then extract the DC component using a PI controller; The DC signal output by the PI controller is quantized by the ADC and used to control the gain of the DPGA, thereby maintaining a constant amplitude of the resonant signal through the MEMS resonator; at the same time, it is used to calculate the gain of the MEMS resonator and TIA, and then obtain the Q value of the MEMS resonator. Based on the inverse relationship between the Q value and temperature, the temperature information of the MEMS resonator is obtained in real time through the signal quantized by the ADC.

10. The silicon resonator in-situ temperature detection circuit based on drive power quantization according to claim 9, characterized in that, A notch filter is also provided between the ADC and the DPGA. The notch filter is used to reduce the quantization noise of the ADC at frequencies of 1000-1000 Hz. The influence of the resonant signal.

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