A conditioning circuit for an IEPE acceleration sensor

Abstract

The present application provides a conditioning circuit for an IEPE acceleration sensor, the conditioning circuit including a constant current source, characterized in that the conditioning circuit further includes: a signal processing circuit and a dual power supply circuit; the positive output terminal of the dual power supply circuit is respectively connected to the input terminal of the constant current source and the positive input terminal of the signal processing circuit, for providing a positive voltage to the constant current source and the signal processing circuit, respectively; the negative output terminal of the dual power supply circuit is connected to the negative input terminal of the signal processing circuit, for providing a negative voltage to the signal processing circuit; the signal processing circuit is configured to, after receiving a raw acceleration signal sent by the IEPE sensor, perform signal processing on the raw acceleration signal to obtain an acceleration signal. The conditioning circuit can increase the amplitude of the signal processed in the signal processing circuit, thereby improving the signal-to-noise ratio of the output signal.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a conditioning circuit for an IEPE acceleration sensor. Background Art

[0002] An IEPE accelerometer converts acceleration into an electrical signal. The output signal of an IEPE accelerometer is a weak signal with a DC bias, typically in the millivolt or microvolt range. This signal is susceptible to external interference, resulting in high noise levels. Therefore, the output signal must be conditioned to increase the signal-to-noise ratio (SNR) to meet the analog input requirements of subsequent circuits and the closed-loop feedforward requirements of high-precision workbenches.

[0003] Currently, existing IEPE accelerometer conditioning circuits typically utilize a single power supply or battery to save space and reduce power consumption. However, in this single-power or battery-powered solution, the IEPE accelerometer's output signal is conditioned between the positive voltage rail and ground. Due to this limitation, the output signal's signal-to-noise ratio is low, failing to meet the analog input requirements of subsequent circuits or the closed-loop feedforward requirements of high-precision workbenches. Summary of the Invention

[0004] In view of this, the purpose of the embodiments of the present application is to provide an IEPE acceleration sensor conditioning circuit, which increases the signal amplitude range by using dual power supplies, thereby solving the problem of low signal-to-noise ratio of the output signal of the IEPE acceleration sensor in the prior art.

[0005] The embodiment of the present application provides a conditioning circuit for an IEPE acceleration sensor, wherein the conditioning circuit includes a constant current source, and the conditioning circuit further includes: a signal processing circuit and a dual power supply circuit;

[0006] The positive output terminal of the dual power supply circuit is connected to the input terminal of the constant current source and the positive input terminal of the signal processing circuit respectively, for providing positive voltage to the constant current source and the signal processing circuit respectively;

[0007] The negative output terminal of the dual power supply circuit is connected to the negative input terminal of the signal processing circuit, so as to provide a negative voltage for the signal processing circuit;

[0008] The signal processing circuit is used to perform signal processing on the original acceleration signal after receiving the original acceleration signal sent by the IEPE sensor to obtain an acceleration signal.

[0009] Optionally, the signal processing circuit includes: a high-pass filtering unit, a primary amplifying unit, a low-pass filtering unit, a secondary amplifying unit and a single-ended to differential conversion unit;

[0010] The high-pass filtering unit is used to receive the original acceleration signal sent by the IEPE acceleration sensor, perform DC bias processing on the original acceleration signal to obtain an AC acceleration signal, and send the AC acceleration signal to the primary amplification unit;

[0011] The primary amplifying unit is used to perform primary amplification processing on the received AC acceleration signal to obtain a primary amplified signal, and send the primary amplified signal to the low-pass filtering unit;

[0012] The low-pass filtering unit is used to perform high-frequency noise filtering on the received primary amplified signal to obtain an acceleration signal, and send the acceleration signal to the secondary amplifying unit;

[0013] The secondary amplification unit is used to perform secondary amplification processing on the received acceleration signal to obtain an amplified acceleration signal, and send the amplified acceleration signal to the single-ended to differential unit;

[0014] The single-ended to differential conversion unit is used to perform single-ended to differential conversion processing on the received amplified acceleration signal to obtain an acceleration signal.

[0015] Optionally, the positive output terminal of the dual power supply circuit is connected to the input terminal of the constant current source and the positive input terminal of the signal processing circuit, respectively, for providing positive voltages to the constant current source and the signal processing circuit, respectively; the negative output terminal of the dual power supply circuit is connected to the negative input terminal of the signal processing circuit, for providing negative voltages to the signal processing circuit, including:

[0016] The positive output terminal of the dual power supply circuit is connected to the input terminal of the constant current source, so as to provide a positive voltage to the constant current source;

[0017] The positive output end of the dual power supply circuit is connected to the positive input ends of the high-pass filter unit, the primary amplifying unit, the low-pass filter unit, the secondary amplifying unit and the single-ended differential conversion unit, respectively, for providing positive voltages to the high-pass filter unit, the primary amplifying unit, the low-pass filter unit, the secondary amplifying unit and the single-ended differential conversion unit, respectively;

[0018] The negative output end of the dual power supply circuit is respectively connected to the negative input ends of the high-pass filtering unit, the primary amplifying unit, the low-pass filtering unit, the secondary amplifying unit and the single-ended differential conversion unit, and is used to provide negative voltages to the high-pass filtering unit, the primary amplifying unit, the low-pass filtering unit, the secondary amplifying unit and the single-ended differential conversion unit respectively.

[0019] Optionally, the dual power supply circuit includes: a power supply, a switching voltage regulator unit, a first low voltage difference linear voltage regulator unit, a second low voltage difference linear voltage regulator unit, a third low voltage difference linear voltage regulator unit and a boost voltage regulator unit;

[0020] The output end of the power supply is connected to the input end of the switching voltage stabilizing unit, and is used to provide an initial positive voltage for the switching voltage stabilizing unit;

[0021] The positive output end of the switching voltage regulator unit is respectively connected to the positive input end of the boost voltage regulator unit, the positive input end of the first low voltage difference linear voltage regulator unit and the positive input end of the third low voltage difference linear voltage regulator unit, and the negative output end of the switching voltage regulator unit is respectively connected to the negative input end of the second low voltage difference linear voltage regulator unit and the negative input end of the third low voltage difference linear voltage regulator unit, and is used to boost the initial positive voltage into a regulated positive and negative voltage after receiving the initial positive voltage, and provide the regulated positive voltage of the regulated positive and negative voltages to the first low voltage difference linear voltage regulator unit, the third low voltage difference linear voltage regulator unit and the boost voltage regulator unit, and provide the regulated negative voltage of the first positive and negative voltages to the second low voltage difference linear voltage regulator unit and the third low voltage difference linear voltage regulator unit.

[0022] Optionally, the positive output end of the dual power supply circuit is respectively connected to the positive input end of the high-pass filtering unit, the primary amplifying unit, the low-pass filtering unit, the secondary amplifying unit and the single-ended differential conversion unit, and is used to provide positive voltages to the high-pass filtering unit, the primary amplifying unit, the low-pass filtering unit, the secondary amplifying unit and the single-ended differential conversion unit respectively; the negative output end of the dual power supply circuit is respectively connected to the negative input end of the high-pass filtering unit, the primary amplifying unit, the low-pass filtering unit, the secondary amplifying unit and the single-ended differential conversion unit, and is used to provide negative voltages to the high-pass filtering unit, the primary amplifying unit, the low-pass filtering unit, the secondary amplifying unit and the single-ended differential conversion unit respectively, comprising:

[0023] The positive output terminal of the first low-voltage-difference linear voltage regulator unit is respectively connected to the positive input terminal of the high-pass filter unit, the positive input terminal of the primary amplifying unit, the positive input terminal of the low-pass filter unit, and the positive input terminal of the secondary amplifying unit, and is configured to, after receiving the regulated positive voltage, perform voltage stabilization on the regulated positive voltage to obtain a first positive voltage, and provide the first positive voltage to the high-pass filter unit, the primary amplifying unit, the low-pass filter unit, and the secondary amplifying unit respectively;

[0024] The negative output terminal of the second low-voltage-difference linear voltage regulator unit is respectively connected to the negative input terminal of the high-pass filter unit, the negative input terminal of the primary amplifying unit, the negative input terminal of the low-pass filter unit, and the negative input terminal of the secondary amplifying unit, and is configured to, after receiving the regulated negative voltage, perform voltage stabilization on the regulated negative voltage to obtain a first negative voltage, and provide the first negative voltage to the high-pass filter unit, the primary amplifying unit, the low-pass filter unit, and the secondary amplifying unit respectively;

[0025] The positive output terminal of the third low-voltage difference linear voltage regulator unit is connected to the positive input terminal of the single-ended to differential unit, and is used to stabilize the regulated positive voltage after receiving the regulated positive voltage to obtain a second positive voltage, and send the second positive voltage to the single-ended to differential unit; the negative output terminal of the third low-voltage difference linear voltage regulator unit is connected to the negative input terminal of the single-ended to differential unit, and is used to stabilize the regulated negative voltage after receiving the regulated negative voltage to obtain a second negative voltage, and provide the second negative voltage to the single-ended to differential unit.

[0026] Optionally, the boost stabilizing unit includes: a boost unit and a fourth low-voltage-difference linear stabilizing unit; the boost unit is configured to, after receiving the regulated positive voltage provided by the switching stabilizing unit, boost the regulated positive voltage to a third positive voltage, and provide the third positive voltage to the fourth low-voltage-difference linear stabilizing unit;

[0027] The fourth low voltage difference linear voltage stabilizing unit is used for, after receiving the third positive voltage, performing voltage stabilization on the third positive voltage to obtain a fourth positive voltage, and using the fourth positive voltage to power the constant current source.

[0028] Optionally, the switching voltage stabilizing unit is a switching voltage regulator;

[0029] The boost unit is a boost charge pump;

[0030] The first low-voltage-dropout linear voltage stabilizing unit, the second low-voltage-dropout linear voltage stabilizing unit, the third low-voltage-dropout linear voltage stabilizing unit, and the fourth low-voltage-dropout linear voltage stabilizing unit are all low-voltage-dropout linear regulators;

[0031] The high-pass filtering unit is a second-order Sallen Key high-pass filter; the primary amplifying unit is a first-order buffered RC high-pass filter with a first gain; the low-pass filtering unit is a second-order Sallen Key low-pass filter; and the secondary amplifying unit is a first-order buffered RC low-pass filter with a second gain.

[0032] Optionally, the first gain is a 2-fold gain or a 10-fold gain, and the second gain is a 10-fold gain;

[0033] Optionally, the second-order Sallen Key high-pass filter includes a first capacitor, a second capacitor, a first resistor, a second resistor and a third resistor;

[0034] The first-order buffer RC high-pass filter includes a third capacitor, a fourth resistor, a fifth resistor and a sixth resistor;

[0035] The second-order Sallen Key low-pass filter includes a fourth capacitor, a fifth capacitor, a seventh resistor and an eighth resistor;

[0036] The first-order buffer RC low-pass filter includes a sixth capacitor, a ninth resistor, a tenth resistor, an eleventh resistor and a twelfth resistor.

[0037] Optionally, the model of the switching regulator is ADP5070; the model of the first low-voltage dropout linear regulator is ADC7118; the model of the second low-voltage dropout linear regulator is ADP7182; the model of the third low-voltage dropout linear regulator is LT3032; the model of the fourth low-voltage dropout linear regulator is LTC3265; the model of the constant current source is LM334; and the single-ended to differential unit is a fully differential ADC driver chip.

[0038] An embodiment of the present application provides a conditioning circuit for an IEPE acceleration sensor, which supplies power to a signal processing circuit through a dual power supply circuit, thereby increasing the voltage amplitude range of the power supply, making the amplitude of the signal processed by the signal processing circuit higher, thereby improving the signal-to-noise ratio of the output signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0040] Figure 1 A schematic structural diagram of a conditioning circuit for an IEPE acceleration sensor provided by an exemplary embodiment of the present application is shown;

[0041] Figure 2 A schematic structural diagram of a conditioning circuit for an IEPE acceleration sensor provided by another exemplary embodiment of the present application is shown;

[0042] Figure 3 A partial structural diagram of a signal processing circuit provided by an exemplary embodiment of the present application is shown;

[0043] Figure 4 A schematic structural diagram of a conditioning circuit for an IEPE acceleration sensor provided by yet another exemplary embodiment of the present application is shown. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of this application.

[0045] Currently, existing IEPE accelerometer conditioning circuits typically utilize a single power supply or battery to save space and reduce power consumption. However, in this single-power or battery-powered solution, the IEPE accelerometer's output signal is conditioned between the positive voltage rail and ground. This limitation results in a low signal-to-noise ratio (SNR) in the output signal, which cannot meet the analog input requirements of subsequent circuits or the closed-loop feedforward requirements of high-precision workbenches.

[0046] Based on this, an embodiment of the present application provides a conditioning circuit for an IEPE acceleration sensor, which can solve the problem of low signal-to-noise ratio of the output signal of the IEPE acceleration sensor in the prior art.

[0047] It should be noted that before conditioning the original acceleration signal output by the IEPE acceleration sensor according to the conditioning circuit of the IEPE acceleration sensor provided in the exemplary embodiment of the present application, the IEPE acceleration sensor can be installed on a high-precision workbench to obtain the acceleration of the vibrating body on the workbench.

[0048] To facilitate understanding of the embodiments of the present application, a conditioning circuit for an IEPE acceleration sensor disclosed in the embodiments of the present application will be described below with reference to specific examples.

[0049] See also Figure 1 As shown, Figure 1 FIG. 1 shows a schematic diagram of a conditioning circuit for an IEPE acceleration sensor provided by an exemplary embodiment of the present application. Figure 1As shown, an IEPE acceleration sensor conditioning circuit provided by an exemplary embodiment of the present application includes: a constant current source 110, a signal processing circuit 130 and a dual power supply circuit 120;

[0050] Here, the constant current source 110 is configured to generate a constant current after being powered, and transmit the constant current to the IEPE accelerometer to stimulate the IEPE accelerometer to convert the received acceleration into a corresponding electrical signal (i.e., a raw acceleration signal), for subsequent signal processing by the signal processing circuit 130. For example, the constant current source 110 may be a low temperature coefficient current source.

[0051] The positive output terminal of the dual power supply circuit 120 is connected to the input terminal of the constant current source 110 and the positive input terminal of the signal processing circuit 130 respectively, for providing positive voltage to the constant current source 110 and the signal processing circuit 130 respectively;

[0052] The negative output terminal of the dual power supply circuit 120 is connected to the negative input terminal of the signal processing circuit 130 to provide a negative voltage for the signal processing circuit 130;

[0053] The signal processing circuit 130 is configured to process the original acceleration signal after receiving the original acceleration signal sent by the IEPE sensor 100 to obtain an acceleration signal.

[0054] See also Figure 2 , Figure 2 FIG. 1 shows a schematic diagram of a conditioning circuit for an IEPE acceleration sensor provided by another exemplary embodiment of the present application. Figure 2 As shown, the signal processing circuit 130 may include: a high-pass filtering unit 131, a primary amplifying unit 132, a low-pass filtering unit 133, a secondary amplifying unit 134, and a single-ended to differential conversion unit 135;

[0055] Here, the high-pass filter unit 131, the primary amplifying unit 132, the low-pass filter unit 133, the secondary amplifying unit 134, and the single-ended to differential conversion unit 135 are sequentially connected in series;

[0056] The high-pass filtering unit 131 is used to receive the original acceleration signal sent by the IEPE acceleration sensor, perform DC bias processing on the original acceleration signal to obtain an AC acceleration signal, and send the AC acceleration signal to the primary amplification unit 132;

[0057] The acceleration signal sent by the IEPE accelerometer is typically accompanied by a DC bias, and the DC bias voltage is typically large. For example, when the acceleration signal amplitude is 98mV, the DC bias voltage is typically 13V. This large DC bias voltage results in a low signal-to-noise ratio in the desired conditioned acceleration signal. Therefore, the DC bias is first filtered out by high-pass filtering unit 131 to obtain an AC acceleration signal. This method removes the DC bias from the outset, thereby suppressing amplification drift of the bias level of the input acceleration signal.

[0058] The primary amplifying unit 132 is configured to perform primary amplification processing on the received AC acceleration signal to obtain a primary amplified signal, and send the primary amplified signal to the low-pass filtering unit 133;

[0059] Because the AC acceleration signal obtained after passing through the high-pass filter unit 131 also includes a high-frequency interference signal, the AC acceleration signal and the high-frequency interference signal are simultaneously amplified after passing through the primary amplifier unit 132. The amplified signal becomes the primary amplified signal. The high-frequency interference signal is generally a power supply noise signal or an electromagnetic interference noise signal. The low-pass filter unit 133 is used to filter the received primary amplified signal to remove the high-frequency noise, obtain an acceleration signal, and send the acceleration signal to the secondary amplifier unit 134.

[0060] Here, since the high-frequency interference signal is also amplified after passing through the primary amplifying unit 132 , the amplified high-frequency interference signal needs to be filtered through the low-pass filtering unit 133 .

[0061] The secondary amplifying unit 134 is used to amplify the received acceleration signal to obtain an amplified acceleration signal, and send the amplified acceleration signal to the single-ended to differential conversion unit 135;

[0062] Here, after the high-frequency interference signal is filtered out by the low-pass filter unit 133, the desired acceleration signal is generally obtained. In order to further improve the signal-to-noise ratio, the secondary amplifier unit 134 is used here to amplify the desired acceleration signal to obtain an amplified acceleration signal.

[0063] The single-ended to differential conversion unit 135 is used to perform differential processing on the received amplified acceleration signal to obtain a conditioned acceleration signal; here, differential processing refers to converting the amplified acceleration signal into a differential analog signal, that is, the conditioned acceleration signal is a differential analog signal.

[0064] Next, we will combine Figure 3The circuit structure of the signal processing circuit 130 provided by the exemplary embodiment of the present application is described in detail. Figure 3 , Figure 3 FIG. 1 shows a partial structural diagram of a signal processing circuit 130 provided by an exemplary embodiment of the present application.

[0065] like Figure 3 As shown, the high-pass filter unit 131 and the primary amplifying unit 132 can be implemented by a third-order Butterworth filter combination circuit with a gain. The high-pass filter unit 131 can be a second-order Sallen Key high-pass filter, and the primary amplifying unit 132 can be a first-order buffered RC high-pass filter with a first gain.

[0066] In practical applications, the third-order Butterworth filter with gain can be designed with a passband cutoff frequency of 0.3 Hz and a stopband cutoff frequency of 0.05 Hz. Here, the first gain is designed according to actual conditions, for example, the first gain can be a 2x gain or a 10x gain.

[0067] As an example, the second-order Sallen Key high-pass filter may include a first capacitor C1, a second capacitor C2, a first resistor R1, a second resistor R2, and a third resistor R3. For example, the capacitance value of the first capacitor may be 10uF / 5%, the capacitance value of the second capacitor may be 10uF / 5%, the resistance value of the first resistor may be 5K / 1%, the resistance value of the second resistor may be 107K / 1%, and the resistance value of the third resistor may be 26.7K / 1%.

[0068] As an example, the first-order buffered RC high-pass filter may include a third capacitor, a fourth resistor, a fifth resistor and a sixth resistor; for example, the capacitance value of the third capacitor may be 10uF / 5%, the resistance value of the fourth resistor may be 53.6K / 1%, the resistance value of the fifth resistor may be 10K / 1%, and the resistance value of the sixth resistor may be 10K / 1%.

[0069] As an example, the low-pass filter unit 133 and the secondary amplifier unit 134 can be implemented by a third-order Butterworth filter combination circuit with a gain. The low-pass filter unit 133 can be a second-order Sallen Key low-pass filter; the secondary amplifier unit 134 can be a first-order buffered RC low-pass filter with a second gain. In practical applications, the third-order Butterworth filter with a gain can be designed to have a passband cutoff frequency of 10KHZ and a stopband cutoff frequency of 60KHZ. Here, the second gain is designed according to actual conditions. For example, the second gain can be a 10-fold gain.

[0070] As an example, the second-order Sallen Key low-pass filter may include a fourth capacitor, a fifth capacitor, a seventh resistor, and an eighth resistor. For example, the capacitance value of the fourth capacitor may be 16 nF / 5%, the capacitance value of the fifth capacitor may be 1.6 nF / 5%, the resistance value of the seventh resistor may be 1.13 K / 1%, and the resistance value of the eighth resistor may be 8.87 K / 1%.

[0071] The first-order buffered RC low-pass filter may include a sixth capacitor, a ninth resistor, a tenth resistor, an eleventh resistor, and a twelfth resistor. For example, the capacitance of the sixth capacitor may be 3.16 nF / 1%, the resistance of the ninth resistor may be 1 kJ / 1%, the resistance of the tenth resistor may be 50 kJ / 1%, the resistance of the eleventh resistor may be 316 kJ / 1%, and the resistance of the twelfth resistor may be 2.87 kJ / 5%.

[0072] As an example, the single-ended to differential conversion unit 135 may be a fully differential ADC driver chip.

[0073] By conditioning the raw acceleration signal in the above manner, two-stage signal amplification processing can be achieved simultaneously, reducing signal harmonic distortion and improving the circuit's signal-to-noise ratio. Furthermore, because the embodiment of the present application utilizes a dual power supply circuit 120 to power the signal processing circuit 130, the amplitude of the signal processing can be increased after conditioning each component in the signal conditioning circuit, thereby achieving a higher signal-to-noise ratio for the resulting conditioned acceleration signal.

[0074] Next, we will combine Figure 2 The following describes how the dual power supply circuit 120 supplies power to the signal processing circuit 130 when the signal processing circuit 130 includes: a high-pass filtering unit 131, a primary amplifying unit 132, a low-pass filtering unit 133, a secondary amplifying unit 134, and a single-ended to differential conversion unit 135.

[0075] like Figure 2 As shown, the positive output terminal of the dual power supply circuit 120 can be connected to the positive input terminals of the high-pass filtering unit 131, the primary amplifying unit 132, the low-pass filtering unit 133, the secondary amplifying unit 134 and the single-ended differential conversion unit 135 respectively, so as to provide positive voltages to the high-pass filtering unit 131, the primary amplifying unit 132, the low-pass filtering unit 133, the secondary amplifying unit 134 and the single-ended differential conversion unit 135 respectively;

[0076] The negative output end of the dual power supply circuit 120 can be connected to the negative input ends of the high-pass filtering unit 131, the primary amplifying unit 132, the low-pass filtering unit 133, the secondary amplifying unit 134 and the single-ended differential conversion unit 135 respectively, and is used to provide negative voltages to the high-pass filtering unit 131, the primary amplifying unit 132, the low-pass filtering unit 133, the secondary amplifying unit 134 and the single-ended differential conversion unit 135 respectively.

[0077] See also Figure 4 , Figure 4 A schematic structural diagram of a conditioning circuit for an IEPE acceleration sensor provided by yet another exemplary embodiment of the present application is shown.

[0078] like Figure 4 As shown, the dual power supply circuit 120 may include: a power supply 121, a switching voltage regulator unit 122, a first low voltage difference linear voltage regulator unit 123, a second low voltage difference linear voltage regulator unit 124, a third low voltage difference linear voltage regulator unit 125 and a boost voltage regulator unit 126;

[0079] The output end of the power supply 121 is connected to the input end of the switching voltage stabilizing unit 122 to provide an initial positive voltage to the switching voltage stabilizing unit 122 ; for example, the initial positive voltage may be +5V.

[0080] The positive output end of the switching voltage regulator unit 122 is respectively connected to the positive input end of the boost voltage regulator unit 126, the positive input end of the first low-voltage difference linear voltage regulator unit 123 and the positive input end of the third low-voltage difference linear voltage regulator unit 125, and the negative output end of the switching voltage regulator unit 122 is respectively connected to the negative input end of the second low-voltage difference linear voltage regulator unit 124 and the negative input end of the third low-voltage difference linear voltage regulator unit 125, and is used to boost the initial positive voltage into a regulated positive and negative voltage after receiving the initial positive voltage, and provide the regulated positive voltage of the regulated positive and negative voltages to the first low-voltage difference linear voltage regulator unit 123, the third low-voltage difference linear voltage regulator unit 125 and the boost voltage regulator unit 126, and provide the regulated negative voltage of the regulated positive and negative voltages to the second low-voltage difference linear voltage regulator unit 124 and the third low-voltage difference linear voltage regulator unit 125.

[0081] Here, as an example, the regulated positive and negative voltages may be ±16V, wherein the regulated positive voltage is +16V and the regulated negative voltage is -16V.

[0082] As an example, the boost stabilizing unit 126 may include: a boost unit 1261 and a fourth low-dropout linear stabilizing unit 1262 ;

[0083] The boost unit 1261 is configured to, after receiving the regulated positive voltage provided by the switching voltage regulator unit 122, boost the regulated positive voltage to a third positive voltage, and provide the third positive voltage to the fourth low voltage difference linear voltage regulator unit 1262; for example, when the regulated positive voltage is +16V, the third positive voltage may be +24V;

[0084] The fourth low voltage difference linear voltage regulator unit 1262 is used to stabilize the third positive voltage after receiving the third positive voltage to obtain a fourth positive voltage, and use the fourth positive voltage to power the constant current source 110. For example, the fourth positive voltage can be a stabilized +24V voltage.

[0085] Next, we will combine Figure 4 The following describes how the dual power supply circuit 120 supplies power to the signal processing circuit 130 when the dual power supply circuit 120 includes: a power supply 121, a switching voltage regulator unit 122, a first low voltage difference linear voltage regulator unit 123, a second low voltage difference linear voltage regulator unit 124, a third low voltage difference linear voltage regulator unit 125 and a boost voltage regulator unit 126.

[0086] Specifically, the positive output end of the first low-voltage difference linear voltage regulator unit 123 is respectively connected to the positive input end of the high-pass filtering unit 131, the positive input end of the primary amplifying unit 132, the positive input end of the low-pass filtering unit 133 and the positive input end of the secondary amplifying unit 134, so as to perform voltage stabilization on the regulated positive voltage after receiving the regulated positive voltage to obtain a first positive voltage, and provide the first positive voltage to the high-pass filtering unit 131, the primary amplifying unit 132, the low-pass filtering unit 133 and the secondary amplifying unit 134 respectively; for example, the first positive voltage can be a stabilized +15V voltage.

[0087] The negative output end of the second low-voltage difference linear voltage regulator unit 124 is respectively connected to the negative input end of the high-pass filter unit 131, the negative input end of the primary amplifying unit 132, the negative input end of the low-pass filter unit 133 and the negative input end of the secondary amplifying unit 134, so as to perform voltage stabilization on the regulated negative voltage after receiving the regulated negative voltage to obtain a first negative voltage, and provide the first negative voltage to the high-pass filter unit 131, the primary amplifying unit 132, the low-pass filter unit 133 and the secondary amplifying unit 134 respectively; for example, the first negative voltage can be a stabilized -15V voltage.

[0088] The positive output terminal of the third low-voltage-dropout linear voltage regulator 125 is connected to the positive input terminal of the single-ended-to-differential conversion unit 135, and is configured to, after receiving the regulated positive voltage, perform voltage stabilization processing on the regulated positive voltage to obtain a second positive voltage, and then send the second positive voltage to the single-ended-to-differential conversion unit 135. The negative output terminal of the third low-voltage-dropout linear voltage regulator 125 is connected to the negative input terminal of the single-ended-to-differential conversion unit 135, and is configured to, after receiving the regulated negative voltage, perform voltage stabilization processing on the regulated negative voltage to obtain a second negative voltage, and then send the second negative voltage to the single-ended-to-differential conversion unit 135. For example, the second positive voltage may be a regulated +5V voltage, and the second negative voltage may be a regulated -5V voltage.

[0089] In addition, in a specific implementation, the switching voltage regulator unit 122 may be a switching voltage regulator; the model of the switching voltage regulator may be ADP5070;

[0090] The boost unit 1261 may be a boost charge pump;

[0091] The first low-dropout linear voltage regulator unit 123, the second low-dropout linear voltage regulator unit 124, the third low-dropout linear voltage regulator unit 125 and the fourth low-dropout linear voltage regulator unit 1262 may all be low-dropout linear voltage regulators; the model of the first low-dropout linear voltage regulator may be ADC7118; the model of the second low-dropout linear voltage regulator may be ADP7182; the model of the third low-dropout linear voltage regulator may be LT3032; the model of the fourth low-dropout linear voltage regulator may be LTC3265; the model of the constant current source 110 may be LM334;

[0092] In the above approach, the dual power supply circuit that powers the signal processing circuit provides positive and negative voltages for the signal processing circuit. This increases the voltage amplitude range of the power supply, compared to the prior art single power supply that only provides a positive voltage. Because the amplitude of the processed signal must be within the voltage amplitude range provided by the power supply, the above approach allows the signal processing circuit to achieve a higher amplitude, thereby improving the signal-to-noise ratio of the output signal.

[0093] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. There may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed may be through some communication interface, indirect coupling or communication connection of devices or units, which may be electrical, mechanical or other forms.

[0094] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0095] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0096] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0097] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The scope of protection of the present application is not limited thereto. Although the present application has been described in detail with reference to the above-mentioned embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-mentioned embodiments within the technical scope disclosed in the present application, or perform equivalent replacements for some of the technical features thereof. These modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A conditioning circuit for an IEPE acceleration sensor, the conditioning circuit comprising a constant current source, characterized in that: The conditioning circuit further comprises: a signal processing circuit and a dual power supply circuit; The positive output terminal of the dual power supply circuit is connected to the input terminal of the constant current source and the positive input terminal of the signal processing circuit respectively, for providing positive voltage to the constant current source and the signal processing circuit respectively; The negative output terminal of the dual power supply circuit is connected to the negative input terminal of the signal processing circuit, so as to provide a negative voltage for the signal processing circuit; The dual power supply circuit includes: a power supply, a switching voltage regulator unit, a first low-voltage difference linear voltage regulator unit, a second low-voltage difference linear voltage regulator unit, a third low-voltage difference linear voltage regulator unit and a boost voltage regulator unit; the signal processing circuit includes: a high-pass filter unit, a primary amplifying unit, a low-pass filter unit, a secondary amplifying unit and a single-ended to differential converter unit; The positive output terminal and the negative output terminal of the dual power supply circuit are respectively connected to the positive input terminal and the negative input terminal of the high-pass filtering unit, the primary amplifying unit, the low-pass filtering unit, the secondary amplifying unit and the single-ended differential conversion unit, respectively, for providing a positive voltage and a negative voltage to the high-pass filtering unit, the primary amplifying unit, the low-pass filtering unit, the secondary amplifying unit and the single-ended differential conversion unit; The positive output terminal of the first low-voltage-difference linear voltage regulator unit is respectively connected to the positive input terminal of the high-pass filter unit, the positive input terminal of the primary amplifying unit, the positive input terminal of the low-pass filter unit, and the positive input terminal of the secondary amplifying unit, and is configured to, after receiving a stabilized positive voltage, perform voltage stabilization on the stabilized positive voltage to obtain a first positive voltage, and provide the first positive voltage to the high-pass filter unit, the primary amplifying unit, the low-pass filter unit, and the secondary amplifying unit respectively; The negative output terminal of the second low-voltage-difference linear voltage regulator unit is respectively connected to the negative input terminal of the high-pass filter unit, the negative input terminal of the primary amplifying unit, the negative input terminal of the low-pass filter unit, and the negative input terminal of the secondary amplifying unit, and is configured to, after receiving the regulated negative voltage, perform voltage stabilization on the regulated negative voltage to obtain a first negative voltage, and provide the first negative voltage to the high-pass filter unit, the primary amplifying unit, the low-pass filter unit, and the secondary amplifying unit respectively; The positive output terminal of the third low-voltage-difference linear voltage regulator unit is connected to the positive input terminal of the single-ended-to-differential conversion unit, and is used to, after receiving the regulated positive voltage, perform voltage stabilization processing on the regulated positive voltage to obtain a second positive voltage, and send the second positive voltage to the single-ended-to-differential conversion unit; the negative output terminal of the third low-voltage-difference linear voltage regulator unit is connected to the negative input terminal of the single-ended-to-differential conversion unit, and is used to, after receiving the regulated negative voltage, perform voltage stabilization processing on the regulated negative voltage to obtain a second negative voltage, and provide the second negative voltage to the single-ended-to-differential conversion unit; The signal processing circuit is used to perform signal processing on the original acceleration signal after receiving the original acceleration signal sent by the IEPE acceleration sensor to obtain an acceleration signal.

2. The conditioning circuit according to claim 1, characterized in that: The high-pass filtering unit is used to receive the original acceleration signal sent by the IEPE acceleration sensor, perform DC bias processing on the original acceleration signal to obtain an AC acceleration signal, and send the AC acceleration signal to the primary amplification unit; The primary amplifying unit is used to perform primary amplification processing on the received AC acceleration signal to obtain a primary amplified signal, and send the primary amplified signal to the low-pass filtering unit; The low-pass filtering unit is used to perform high-frequency noise filtering on the received primary amplified signal to obtain an acceleration signal, and send the acceleration signal to the secondary amplifying unit; The secondary amplification unit is used to perform secondary amplification processing on the received acceleration signal to obtain an amplified acceleration signal, and send the amplified acceleration signal to the single-ended to differential unit; The single-ended to differential conversion unit is used to perform single-ended to differential conversion processing on the received amplified acceleration signal to obtain an acceleration signal.

3. The conditioning circuit according to claim 1, characterized in that: The output end of the power supply is connected to the input end of the switching voltage stabilizing unit, and is used to provide an initial positive voltage for the switching voltage stabilizing unit; The positive output end of the switching voltage regulator unit is respectively connected to the positive input end of the boost voltage regulator unit, the positive input end of the first low voltage difference linear voltage regulator unit and the positive input end of the third low voltage difference linear voltage regulator unit, and the negative output end of the switching voltage regulator unit is respectively connected to the negative input end of the second low voltage difference linear voltage regulator unit and the negative input end of the third low voltage difference linear voltage regulator unit, and is used to boost the initial positive voltage into a regulated positive and negative voltage after receiving the initial positive voltage, and provide the regulated positive voltage of the regulated positive and negative voltages to the first low voltage difference linear voltage regulator unit, the third low voltage difference linear voltage regulator unit and the boost voltage regulator unit, and provide the regulated negative voltage of the regulated positive and negative voltages to the second low voltage difference linear voltage regulator unit and the third low voltage difference linear voltage regulator unit.

4. The conditioning circuit according to claim 1 or 3, characterized in that: The boost and voltage stabilization unit includes: a boost unit and a fourth low voltage difference linear voltage stabilization unit; The boost unit is configured to, after receiving the regulated positive voltage provided by the switching voltage stabilizing unit, boost the regulated positive voltage to a third positive voltage, and provide the third positive voltage to the fourth low voltage difference linear voltage stabilizing unit; The fourth low voltage difference linear voltage stabilizing unit is used for, after receiving the third positive voltage, performing voltage stabilization on the third positive voltage to obtain a fourth positive voltage, and using the fourth positive voltage to power the constant current source.

5. The conditioning circuit according to claim 4, characterized in that: The switching voltage stabilizing unit is a switching voltage stabilizer; The boost unit is a boost charge pump; The first low-voltage-dropout linear voltage stabilizing unit, the second low-voltage-dropout linear voltage stabilizing unit, the third low-voltage-dropout linear voltage stabilizing unit, and the fourth low-voltage-dropout linear voltage stabilizing unit are all low-voltage-dropout linear regulators; The high-pass filtering unit is a second-order Sallen Key high-pass filter; the primary amplifying unit is a first-order buffered RC high-pass filter with a first gain; the low-pass filtering unit is a second-order Sallen Key low-pass filter; and the secondary amplifying unit is a first-order buffered RC low-pass filter with a second gain.

6. The conditioning circuit according to claim 5, characterized in that: The first gain is a 2-fold gain or a 10-fold gain, and the second gain is a 10-fold gain.

7. The conditioning circuit according to claim 5, characterized in that: The second-order Sallen Key high-pass filter includes a first capacitor, a second capacitor, a first resistor, a second resistor and a third resistor; The first-order buffer RC high-pass filter includes a third capacitor, a fourth resistor, a fifth resistor and a sixth resistor; The second-order Sallen Key low-pass filter includes a fourth capacitor, a fifth capacitor, a seventh resistor and an eighth resistor; The first-order buffer RC low-pass filter includes a sixth capacitor, a ninth resistor, a tenth resistor, an eleventh resistor and a twelfth resistor.

8. The conditioning circuit according to claim 5, characterized in that: The model of the switching regulator is ADP5070; the model of the first low-voltage dropout linear regulator is ADC7118; the model of the second low-voltage dropout linear regulator is ADP7182; the model of the third low-voltage dropout linear regulator is LT3032; the model of the fourth low-voltage dropout linear regulator is LTC3265; the model of the constant current source is LM334; the single-ended to differential unit is a fully differential ADC driver chip.

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