CN110995177B - Pre-amplifying circuit with wide input dynamic range and sensor with same - Google Patents
Pre-amplifying circuit with wide input dynamic range and sensor with same Download PDFInfo
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Abstract
The application discloses a pre-amplifying circuit with a wide input dynamic range and a sensor with the same. Wherein, the pre-amplification circuit of wide input dynamic range includes: the device comprises a front-stage signal acquisition circuit, a first-order RC high-pass filter circuit, a voltage follower, a second-order voltage-controlled low-pass filter circuit and a third-order active band-pass filter circuit; the output end of the signal acquisition circuit is connected with the input end of the first-order RC high-pass filter circuit, the output end of the first-order RC high-pass filter circuit is connected with the input end of the voltage follower, the output end of the voltage follower is connected with the input end of the second-order voltage-controlled low-pass filter circuit, and the output end of the second-order voltage-controlled low-pass filter circuit is connected with the input end of the third-order active band-pass filter circuit; the third-order active band-pass filter circuit comprises a second first-order RC high-pass filter circuit, a third-order RC low-pass filter circuit and an operational amplifier circuit, and the second first-order RC high-pass filter circuit, the third-order RC low-pass filter circuit and the operational amplifier circuit are connected in series.
Description
Technical Field
The application relates to the technical field of amplifying circuits, in particular to a pre-amplifying circuit with a wide input dynamic range and a sensor with the pre-amplifying circuit.
Background
With the rapid development of electronic information science and technology, sensor technology has been widely applied in the fields of traffic, machinery, electric power and the like, and corresponding sensor signal processing technology has also been greatly improved. At present, when many sensors, such as piezoelectric sensors, pressure sensors, piezoelectric hydrophones and other capacitive sensors work, the electric charge proportional to the measured physical quantity can be output, and the electric charge has better linearity, but the generated electric charge is weak, so that a pre-amplifying circuit matched with the electric charge is needed to convert the generated electric charge and amplify signals. At present, the existing pre-amplifying circuit can realize collection and conversion of micro charges and amplification of signals, but the maximum input range of the signals is limited, the dynamic range is smaller, and the effect of band-pass filtering is also different according to the designed circuit performance. Therefore, research on a pre-amplifying circuit with a wide input dynamic range has high practical value.
Disclosure of Invention
The object of the present application is to solve at least to some extent one of the above-mentioned technical problems.
To this end, a first object of the present application is to propose a pre-amplification circuit with a wide input dynamic range, having the following advantages: 1) A wide input dynamic range; 2) The passband is stable, and the filtering effect is good; 3) The reliability of the circuit design scheme for collecting and converting micro charges and amplifying signals is high; 4) The circuit performance is stable, and the signal to noise ratio is high.
A second object of the application is to propose a sensor.
In order to achieve the above object, an embodiment of a first aspect of the present application provides a pre-amplifying circuit with a wide input dynamic range, including:
the device comprises a front-stage signal acquisition circuit, a first-order RC high-pass filter circuit, a voltage follower, a second-order voltage-controlled low-pass filter circuit and a third-order active band-pass filter circuit;
the output end of the signal acquisition circuit is connected with the input end of the first-order RC high-pass filter circuit, the output end of the first-order RC high-pass filter circuit is connected with the input end of the voltage follower, the output end of the voltage follower is connected with the input end of the second-order voltage-controlled low-pass filter circuit, and the output end of the second-order voltage-controlled low-pass filter circuit is connected with the input end of the third-order active band-pass filter circuit;
the third-order active band-pass filter circuit comprises a second first-order RC high-pass filter circuit, a third-order RC low-pass filter circuit and an operational amplifier circuit, wherein the second first-order RC high-pass filter circuit, the third-order RC low-pass filter circuit and the operational amplifier circuit are connected in series.
Optionally, an output end of the second first-order RC high-pass filter circuit is connected with an input end of the third-order RC low-pass filter circuit, and an output end of the third-order RC low-pass filter circuit is connected with an input end of the operational amplifier circuit; or alternatively
The output end of the third-order RC low-pass filter circuit is connected with the input end of the second first-order RC high-pass filter circuit, and the output end of the second first-order RC high-pass filter circuit is connected with the input end of the operational amplifier circuit.
Optionally, the pre-stage signal acquisition circuit includes a charge source Q 0 Equivalent capacitance C of charge source 0 Capacitance C 1 Resistance R 1 Operational amplifier U 1A Resistor R 2 ，
Wherein the charge source Q 0 The charge source equivalent capacitance C 0 Said capacitor C 1 Said resistor R 1 In parallel with the charge source Q 0 The charge source equivalent capacitance C 0 Said capacitor C 1 Said resistor R 1 Is connected with one end of the operational amplifier U 1A Is connected to the positive input terminal of the charge source Q 0 The charge source equivalent capacitance C 0 Said capacitor C 1 Said resistor R 1 The other end of the first electrode is grounded;
the resistor R 2 Is connected with one end of the operational amplifier U 1A Is connected to the negative input terminal of the resistor R 2 Is connected with the other end of the operational amplifier U 1A Is connected with the output end of the power supply;
the operational amplifier U 1A Two capacitors C are connected in parallel between the positive power supply end and the ground 2 And C 3 The operational amplifier U 1A Two capacitors C are connected in parallel between the negative power supply end and the ground 4 And C 5 。
Optionally, the first-order RC high-pass filter circuit includes a capacitor C 6 Resistance R 3 The capacitor C 6 Is connected with one end of the operational amplifier U 1A Is connected with the output end of the capacitor C 6 Respectively with the other end of the resistor R 3 Is one end of the resistor R 3 The other end of which is grounded.
Optionally, the voltage follower includes an operational amplifier U 1B And resistance R 4 The operational amplifier U 1B Is connected with the positive input end of the capacitor C 6 Is connected to the other end of the operational amplifier U 1B And the negative input terminal of the resistor R 4 Is connected to one end of the housing.
Optionally, the second-order voltage-controlled low-pass filter circuit includes a capacitor C 7 Capacitance C 8 Resistance R 5 Resistance R 6 Resistance R 7 Resistance R 8 Operational amplifier U 2A ，
Wherein the resistor R 5 Is connected with the resistor R 4 Is connected to the other end of the resistor R 5 Respectively with the other end of the resistor R 7 And said capacitor C 7 Is connected to one end of the resistor R 7 Respectively with the other end of the capacitor C 8 And said operational amplifier U 2A Is connected to the positive input terminal of the capacitor C 8 Is grounded at the other end of the operational amplifier U 2A Respectively with the negative input terminal of the resistor R 6 And said resistor R 8 Is connected to one end of the resistor R 6 The other end of the resistor R is grounded 8 Is connected with the other end of the operational amplifier U 2A Is connected with the output end of the operational amplifier U 2A Two capacitors C are connected in parallel between the positive power supply end and the ground 9 And C 10 The operational amplifier U 2A Two capacitors C are connected in parallel between the negative power supply end and the ground 11 And C 12 。
Optionally, the third-order RC low-pass filter circuit comprises a resistor R 9 Resistance R 10 Resistance R 11 Capacitance C 13 Capacitance C 14 Capacitance C 15 ，
Wherein the resistor R 9 Said resistor R 10 Said resistor R 11 In series with the resistor R 9 Is used as the input end of the third-order RC low-pass filter circuit, the resistor R 11 The output end of the third-order RC low-pass filter circuit;
the capacitor C 13 Is connected with the resistor R 9 Is connected with the output end of the capacitor C 13 The other end of the capacitor C is grounded 14 Is connected with the resistor R 10 Is connected with the output end of the capacitor C 14 The other end of the capacitor C is grounded 15 Is connected with the resistor R 11 Is connected with the output end of the capacitor C 15 The other end of which is grounded.
Optionally, the second first order RC high pass filteringThe circuit comprises a capacitor C 16 And resistance R 12 The capacitor C 16 Is used as the input end of the second first-order RC high-pass filter circuit, the capacitor C 16 Is used as the output end of the second first-order RC high-pass filter circuit, the resistor R 12 Is connected with one end of the capacitor C 16 Is connected with the output end of the resistor R 12 The other end of which is grounded.
Optionally, the operational amplifier circuit includes an operational amplifier U 2B Resistance R 13 Resistance R 14 The operational amplifier U 2B Is used as the input end of the operational amplifier circuit, the operational amplifier U 2B Two capacitors C are connected in parallel between the positive power supply end and the ground 17 And C 18 The operational amplifier U 2B Two capacitors C are connected in parallel between the negative power supply end and the ground 19 And C 20 The operational amplifier U 2B Respectively with the negative input terminal of the resistor R 13 And the resistance R 14 Is connected to one end of the resistor R 13 The other end of the resistor R is grounded 14 Is connected with the other end of the operational amplifier U 2B Is connected to the output terminal of the (c).
The pre-amplifying circuit with wide input dynamic range provided by the embodiment of the application has the following advantages: 1) A wide input dynamic range; 2) The passband is stable, and the filtering effect is good; 3) The reliability of the circuit design scheme for collecting and converting micro charges and amplifying signals is high; 4) The circuit performance is stable, and the signal to noise ratio is high.
In order to achieve the above object, a second aspect of the present application provides a sensor including the wide input dynamic range pre-amplification circuit of the previous embodiment, the sensor including a piezoelectric capacitive sensor.
Additional aspects and advantages of the application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the application.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:
FIG. 1 is a circuit diagram of a wide input dynamic range pre-amp circuit according to one embodiment of the application;
FIG. 1a is a circuit diagram of a third order active bandpass filter circuit according to one embodiment of the application;
FIG. 1b is a circuit diagram two of a third order active bandpass filter circuit according to one embodiment of the application;
FIG. 2 is a circuit diagram of a wide input dynamic range pre-amp circuit according to an embodiment of the present application;
FIG. 3 is a circuit diagram of a pre-stage signal acquisition circuit according to one embodiment of the present application;
FIG. 3a is a diagram of an equivalent circuit of a charge source according to an embodiment of the present application;
FIG. 3b is a simplified charge source equivalent circuit diagram of one embodiment of the present application;
FIG. 4 is a circuit diagram of a second order voltage controlled low pass filter circuit in accordance with one embodiment of the present application;
FIG. 5 is a schematic diagram of circuit simulation results according to an embodiment of the present application;
fig. 6 is a graph of amplitude versus frequency of actual measured data for one embodiment of the present application.
Detailed Description
It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.
The application is described in further detail below in connection with specific examples which are not to be construed as limiting the scope of the application as claimed.
A wide input dynamic range pre-amplifier circuit and a sensor having the same according to an embodiment of the present application are described below with reference to the accompanying drawings.
Fig. 1 is a circuit diagram of a wide input dynamic range pre-amp circuit according to an embodiment of the application.
As shown in fig. 1, the pre-amplification circuit with a wide input dynamic range includes a pre-stage signal acquisition circuit 110, a first-order RC high-pass filter circuit 120, a voltage follower 130, a second-order voltage-controlled low-pass filter circuit 140, and a third-order active band-pass filter circuit 150.
The specific connection manner is as follows, the output end of the signal acquisition circuit 110 is connected to the input end of the first-order RC high-pass filter circuit 120, the output end of the first-order RC high-pass filter circuit 120 is connected to the input end of the voltage follower 130, the output end of the voltage follower 130 is connected to the input end of the second-order voltage-controlled low-pass filter circuit 140, and the output end of the second-order voltage-controlled low-pass filter circuit 140 is connected to the input end of the third-order active band-pass filter circuit 150.
The third-order active band-pass filter circuit 150 further includes a second first-order RC high-pass filter circuit 151, a third-order RC low-pass filter circuit 152, and an operational amplifier circuit 153, and the second first-order RC high-pass filter circuit 151, the third-order RC low-pass filter circuit 152, and the operational amplifier circuit 153 are connected in series.
In one embodiment of the present application, the connection of the second first order RC high pass filter circuit 151, the third order RC low pass filter circuit 152, and the operational amplifier circuit 153 in series may include two ways:
as shown in fig. 1a, the output terminal of the second first-order RC high-pass filter circuit 151 is connected to the input terminal of the third-order RC low-pass filter circuit 152, and the output terminal of the third-order RC low-pass filter circuit 152 is connected to the input terminal of the operational amplifier circuit 153.
As shown in fig. 1b, the output terminal of the third-order RC low-pass filter circuit 152 is connected to the input terminal of the second first-order RC high-pass filter circuit 151, and the output terminal 151 of the second first-order RC high-pass filter circuit is connected to the input terminal of the operational amplifier circuit 153.
The wide input dynamic range pre-amplifier circuit of the present application is described in detail below with one specific embodiment.
Fig. 2 is a circuit diagram of a wide input dynamic range pre-amp circuit in accordance with an embodiment of the present application.
As shown in fig. 2, the pre-amplification circuit with a wide input dynamic range includes a pre-stage signal acquisition circuit 210, a first-order RC high-pass filter circuit 220, a voltage follower 230, a second-order voltage-controlled low-pass filter circuit 240, and a third-order active band-pass filter circuit 250.
As shown in fig. 3, the front-stage signal acquisition circuit 210 specifically includes a charge source Q 0 Equivalent capacitance C of charge source 0 Capacitance C 1 Resistance R 1 Operational amplifier U 1A Resistor R 2 。
Wherein the charge source Q 0 Equivalent capacitance C of charge source 0 Capacitance C 1 Resistance R 1 Parallel connection of charge sources Q 0 Equivalent capacitance C of charge source 0 Capacitance C 1 Resistance R 1 One end of (a) and an operational amplifier U 1A Is connected to the positive input terminal of the charge source Q 0 Equivalent capacitance C of charge source 0 Capacitance C 1 Resistance R 1 The other end of the first electrode is grounded; resistor R 2 One end of (a) and an operational amplifier U 1A Is connected with the negative input terminal of the resistor R 2 And the other end of the (B) and the operational amplifier U 1A Is connected with the output end of the power supply; operational amplifier U 1A Two capacitors C are connected in parallel between the positive power supply end and the ground 2 And C 3 Operational amplifier U 1A Two capacitors C are connected in parallel between the negative power supply end and the ground 4 And C 5 。
Operational amplifier U 1A The circuit for collecting the original signal of the piezoelectric sensor is built. Piezoelectric sensor (Charge source Q) 0 ) The original signal of (1) is first transferred to the operational amplifier U 1A Operational amplifier U 1A The charge signals generated by the piezoelectric sensor are converted into voltage signals as much as possible and transmitted, and the larger input impedance is converted into smaller output impedance, so that the transmission of the voltage signals is facilitated.
The principle of designing the front-stage signal acquisition circuit 210 is as follows:
fig. 3a is a charge source equivalent circuit diagram. As shown in fig. 3a, Q 0 Is a charge source, C a Is equivalent capacitance of piezoelectric sensor C c To connect the cable equivalent capacitance C i Inputting power for operational amplifierCapacitor (corresponding to C in FIG. 3 1 )，R a Is equivalent resistance of piezoelectric sensor, R i The input resistor (corresponding to R in fig. 3 1 )，U 0 The output voltage of the operational amplifier. Fig. 3a may be simplified to fig. 3b. Wherein, the capacitor C t ＝C a +C c +C i Resistance, resistanceEquation one can be derived from ohm's law of alternating current:
it is assumed that in the case of steady state simple harmonic input, i.e. charge q=qe jωt Voltage U o ＝Ue jωt Then we can reduce to equation two:
the application selects the input resistor R i Is of the order of mΩ, input capacitance C of the operational amplifier i Equivalent resistance R of piezoelectric sensor of 1uF or more a Up to 10 8 Omega or more. So when the measurement frequency is high, the capacitanceThe equivalent internal capacitance of the piezoelectric sensor is pF magnitude, and the equivalent internal capacitance of the connecting cable is 50pF/m magnitude, so the capacitance C i >>C a +C c C is then t About equal to C i Finally, the formula can be simplified as formula three: />
As shown in the third formula, the charges generated by the deformation of the piezoelectric film are accumulated on the input capacitance of the front-stage signal acquisition circuit as much as possible and converted into voltage signals. The front-end signal acquisition circuit thus designed is shown in fig. 3.
The first-order RC high-pass filter circuit 220 includes a capacitor C 6 Resistance R 3 Capacitance C 6 One end of (a) and an operational amplifier U 1A Is connected with the output end of the capacitor C 6 Respectively with resistor R at the other end 3 One end of the resistor R 3 The other end of which is grounded. Capacitor C 6 Resistance R 3 The circuit is composed of a circuit for blocking the direct current component in the circuit, and is actually a high-pass filter circuit for filtering part of low-frequency interference signals and reducing the power frequency interference of a 50Hz power supply.
The voltage follower 230 includes an operational amplifier U 1B And resistance R 4 . Wherein, operational amplifier U 1B Positive input terminal of (C) and capacitor C 6 Is connected to the other end of the operational amplifier U 1B Negative input terminal of (a) and resistor R 4 Is connected to one end of the housing.
The voltage follower 230 may act as an impedance transformation, changing a large input impedance to a small output impedance.
As shown in fig. 4, the second-order voltage-controlled low-pass filter circuit 240 includes a capacitor C 7 Capacitance C 8 Resistance R 5 Resistance R 6 Resistance R 7 Resistance R 8 Operational amplifier U 2A 。
Wherein the resistance R 5 One end of (2) and resistor R 4 Is connected to the other end of resistor R 5 Respectively with resistor R at the other end 7 And a capacitor C 7 Is connected to one end of resistor R 7 Respectively with the other end of the capacitor C 8 And an operational amplifier U 2A Is connected with the positive input end of the capacitor C 8 Is grounded at the other end of the operational amplifier U 2A Respectively with resistor R 6 And a resistor R 8 Is connected to one end of resistor R 6 Is grounded at the other end of the resistor R 8 And the other end of the (B) and the operational amplifier U 2A Is connected with the output end of the operational amplifier U 2A Two capacitors C are connected in parallel between the positive power supply end and the ground 9 And C 10 Operational amplifier U 2A Two capacitors C are connected in parallel between the negative power supply end and the ground 11 And C 12 。
The circuit shown in fig. 4 can obtain equation four:wherein u is 0 (s) u in the figure 0 (voltage corresponding to this point), u p (s) u in the figure p (voltage corresponding to this point), A up Indicating the operational amplifier (U) 2A ) Is provided.
Formula five:wherein u is i 's', u in FIG. 4 i ' the voltage corresponding to this point,
by using the node current method, the formula six can be obtained:wherein u is i (s) i.e. u in FIG. 4 i And finally, finishing the transfer function which can be obtained as a formula seven:
wherein A is us Is the second order voltage controlled low pass filter circuit gain, i.e. the amplification in the form of a laplace transform.
Let s=jω, ω 0 ＝2πf 0 The frequency characteristic is obtained as formula eight:
equation eight represents the amplitude-frequency response curve of the circuit.
The third-order active bandpass filter circuit 250 further includes a second-order RC high-pass filter circuit 251, a third-order RC low-pass filter circuit 252, and an operational amplifier circuit 253. The output end 252 of the third-order RC low-pass filter circuit is connected to the input end 251 of the second first-order RC high-pass filter circuit, and the output end 251 of the second first-order RC high-pass filter circuit is connected to the input end of the operational amplifier circuit 253.
The second first-order RC high-pass filter circuit 251 includes a capacitor C 16 And resistance R 12 Capacitance C 16 Is used as the input end of the second first order RC high pass filter circuit 251, capacitor C 16 Is used as the output end of the second-order RC high-pass filter circuit 251, resistor R 12 One end of (2) and a capacitor C 16 Is connected with the output end of the resistor R 12 The other end of which is grounded.
The third-order RC low-pass filter circuit 252 includes a resistor R 9 Resistance R 10 Resistance R 11 Capacitance C 13 Capacitance C 14 Capacitance C 15 . Wherein the resistance R 9 Resistance R 10 Resistance R 11 Series connection of resistors R 9 Is used as the input end of the third-order RC low-pass filter circuit 252, resistor R 11 As the output of the third-order RC low-pass filter circuit 252; capacitor C 13 One end of (2) and resistor R 9 Is connected with the output end of the capacitor C 13 The other end of (C) is grounded, the capacitor C 14 One end of (2) and resistor R 10 Is connected with the output end of the capacitor C 14 The other end of (C) is grounded, the capacitor C 15 One end of (2) and resistor R 11 Is connected with the output end of the capacitor C 15 The other end of which is grounded.
For the third order RC low pass filter circuit 252, its corresponding transfer function is represented by equation nine:
wherein, the liquid crystal display device comprises a liquid crystal display device,
then s is changed to jω, while R is made 9 ＝R 10 ＝R 11 ＝R，C 13 ＝C 14 ＝C 15 ＝C，ω 0 ＝2πf 0 =1/(RC), the frequency characteristic of which is expressed by the formula ten:
the operational amplifier circuit 253 includes an operational amplifier U 2B Resistance R 13 Resistance R 14 Operational amplifier U 2B Is used as the input end of the operational amplifier circuit, and the operational amplifier U 2B Two capacitors C are connected in parallel between the positive power supply end and the ground 17 And C 18 Operational amplifier U 2B Two capacitors C are connected in parallel between the negative power supply end and the ground 19 And C 20 Operational amplifier U 2B Respectively with resistor R 13 And resistance R 14 Is connected to one end of resistor R 13 Is grounded at the other end of the resistor R 14 And the other end of the (B) and the operational amplifier U 2B Is connected to the output terminal of the (c).
The third-order active bandpass filter circuit 250 has a wide passband and small ripple in the passband. The method can filter part of low-frequency interference signals and reduce power frequency interference of a 50Hz power supply, so that signals higher than a set frequency are suppressed, and thus, a lot of noise in a circuit can be reduced, and the signal-to-noise ratio is improved.
After the circuit design is completed, simulation software MULTISIM can be utilized to simulate, and the simulation result is shown in FIG. 5, wherein the maximum input signal amplitude range can reach more than 600 mV. The amplitude-frequency curve drawn by the measurement data of the actual circuit is shown in fig. 6, and the amplitude range of the maximum input signal actually measured by the circuit can reach more than 1V.
The pre-amplifying circuit with wide input dynamic range provided by the embodiment of the application has the following advantages: 1) A wide input dynamic range; 2) The passband is stable, and the filtering effect is good; 3) The reliability of the circuit design scheme for collecting and converting micro charges and amplifying signals is high; 4) The circuit performance is stable, and the signal to noise ratio is high.
To achieve the above object, the present application also proposes a sensor including a wide input dynamic range pre-amplification circuit as described in the above embodiment.
It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises an element.
Logic and/or steps represented in the flowcharts or otherwise described herein, e.g., a ordered listing of executable instructions for implementing logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium may even be paper or other suitable medium upon which the program is printed, as the program may be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory.
It is to be understood that portions of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, the various steps or methods may be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, may be implemented using any one or combination of the following techniques, as is well known in the art: discrete logic circuits having logic gates for implementing logic functions on data signals, application specific integrated circuits having suitable combinational logic gates, programmable Gate Arrays (PGAs), field Programmable Gate Arrays (FPGAs), and the like.
It should be noted that in the description of the present specification, descriptions of terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.
Claims (8)
1. A wide input dynamic range pre-amp circuit comprising:
the device comprises a front-stage signal acquisition circuit, a first-order RC high-pass filter circuit, a voltage follower, a second-order voltage-controlled low-pass filter circuit and a third-order active band-pass filter circuit;
the output end of the signal acquisition circuit is connected with the input end of the first-order RC high-pass filter circuit, the output end of the first-order RC high-pass filter circuit is connected with the input end of the voltage follower, the output end of the voltage follower is connected with the input end of the second-order voltage-controlled low-pass filter circuit, and the output end of the second-order voltage-controlled low-pass filter circuit is connected with the input end of the third-order active band-pass filter circuit;
the third-order active band-pass filter circuit comprises a second first-order RC high-pass filter circuit, a third-order RC low-pass filter circuit and an operational amplifier circuit, wherein the second first-order RC high-pass filter circuit, the third-order RC low-pass filter circuit and the operational amplifier circuit are connected in series;
the front-stage signal acquisition circuit comprises a charge source Q 0 Equivalent capacitance C of charge source 0 Capacitance C 1 Resistance R 1 Operational amplifier U 1A Resistor R 2 ，
Wherein the charge source Q 0 The charge source equivalent capacitance C 0 Said capacitor C 1 Said resistor R 1 In parallel with the charge source Q 0 The charge source equivalent capacitance C 0 Said capacitor C 1 Said resistor R 1 One end of (2)And the operational amplifier U 1A Is connected to the positive input terminal of the charge source Q 0 The charge source equivalent capacitance C 0 Said capacitor C 1 Said resistor R 1 The other end of the first electrode is grounded;
the resistor R 2 Is connected with one end of the operational amplifier U 1A Is connected to the negative input terminal of the resistor R 2 Is connected with the other end of the operational amplifier U 1A Is connected with the output end of the power supply;
the operational amplifier U 1A Two capacitors C are connected in parallel between the positive power supply end and the ground 2 And C 3 The operational amplifier U 1A Two capacitors C are connected in parallel between the negative power supply end and the ground 4 And C 5 ；
The first-order RC high-pass filter circuit comprises a capacitor C 6 Resistance R 3 The capacitor C 6 Is connected with one end of the operational amplifier U 1A Is connected with the output end of the capacitor C 6 Respectively with the other end of the resistor R 3 Is one end of the resistor R 3 The other end of the capacitor C is grounded 6 Said resistor R 3 A circuit for blocking the direct current component in the circuit is formed.
2. The pre-amplification circuit of claim 1, wherein an output of the second first-order RC high-pass filter circuit is connected to an input of the third-order RC low-pass filter circuit, and an output of the third-order RC low-pass filter circuit is connected to an input of the operational amplifier circuit; or alternatively
The output end of the third-order RC low-pass filter circuit is connected with the input end of the second first-order RC high-pass filter circuit, and the output end of the second first-order RC high-pass filter circuit is connected with the input end of the operational amplifier circuit.
3. The pre-amplifier circuit of claim 1, wherein the voltage follower comprises an operational amplifier U 1B And resistance R 4 The operational amplifier U 1B Is connected with the positive input end of the capacitor C 6 Is connected to the other end of the operational amplifier U 1B And the negative input terminal of the resistor R 4 Is connected to one end of the housing.
4. The pre-amplification circuit of claim 3, wherein the second-order voltage-controlled low-pass filter circuit comprises a capacitor C 7 Capacitance C 8 Resistance R 5 Resistance R 6 Resistance R 7 Resistance R 8 Operational amplifier U 2A ，
Wherein the resistor R 5 Is connected with the resistor R 4 Is connected to the other end of the resistor R 5 Respectively with the other end of the resistor R 7 And said capacitor C 7 Is connected to one end of the resistor R 7 Respectively with the other end of the capacitor C 8 And said operational amplifier U 2A Is connected to the positive input terminal of the capacitor C 8 Is grounded at the other end of the operational amplifier U 2A Respectively with the negative input terminal of the resistor R 6 And said resistor R 8 Is connected to one end of the resistor R 6 The other end of the resistor R is grounded 8 Is connected with the other end of the operational amplifier U 2A Is connected with the output end of the operational amplifier U 2A Two capacitors C are connected in parallel between the positive power supply end and the ground 9 And C 10 The operational amplifier U 2A Two capacitors C are connected in parallel between the negative power supply end and the ground 11 And C 12 。
5. The pre-amplifier circuit of claim 1 or 2, wherein the third-order RC low-pass filter circuit comprises a resistor R 9 Resistance R 10 Resistance R 11 Capacitance C 13 Capacitance C 14 Capacitance C 15 ，
Wherein the resistor R 9 Said resistor R 10 Said resistor R 11 In series with the resistor R 9 Is used as the input end of the third-order RC low-pass filter circuit, the resistor R 11 As the output of the third order RC low pass filterAn output end of the path;
the capacitor C 13 Is connected with the resistor R 9 Is connected with the output end of the capacitor C 13 The other end of the capacitor C is grounded 14 Is connected with the resistor R 10 Is connected with the output end of the capacitor C 14 The other end of the capacitor C is grounded 15 Is connected with the resistor R 11 Is connected with the output end of the capacitor C 15 The other end of which is grounded.
6. The pre-amplifier circuit of claim 1 or 2, wherein the second first order RC high pass filter circuit comprises a capacitor C 16 And resistance R 12 The capacitor C 16 Is used as the input end of the second first-order RC high-pass filter circuit, the capacitor C 16 Is used as the output end of the second first-order RC high-pass filter circuit, the resistor R 12 Is connected with one end of the capacitor C 16 Is connected with the output end of the resistor R 12 The other end of which is grounded.
7. The pre-amplification circuit of claim 1, wherein the operational amplification circuit comprises an operational amplifier U 2B Resistance R 13 Resistance R 14 The operational amplifier U 2B Is used as the input end of the operational amplifier circuit, the operational amplifier U 2B Two capacitors C are connected in parallel between the positive power supply end and the ground 17 And C 18 The operational amplifier U 2B Two capacitors C are connected in parallel between the negative power supply end and the ground 19 And C 20 The operational amplifier U 2B Respectively with the negative input terminal of the resistor R 13 And the resistance R 14 Is connected to one end of the resistor R 13 The other end of the resistor R is grounded 14 Is connected with the other end of the operational amplifier U 2B Is connected to the output terminal of the (c).
8. A sensor comprising the wide input dynamic range pre-amplification circuit of any one of claims 1-7, the sensor comprising a piezoelectric-based capacitive sensor.
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| CN201911243889.5A CN110995177B (en) | 2019-12-06 | 2019-12-06 | Pre-amplifying circuit with wide input dynamic range and sensor with same |
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| CN201911243889.5A CN110995177B (en) | 2019-12-06 | 2019-12-06 | Pre-amplifying circuit with wide input dynamic range and sensor with same |
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| CN110995177B true CN110995177B (en) | 2023-11-03 |
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|---|---|---|---|---|
| CN101207374A (en) * | 2006-12-21 | 2008-06-25 | 南化集团研究院 | Pre-amplifier circuit used for stroboscopic operation |
| CN203100905U (en) * | 2013-02-05 | 2013-07-31 | 天广消防股份有限公司 | Signal processing circuit of flame detector |
| CN205510002U (en) * | 2016-03-08 | 2016-08-24 | 西安理工大学 | Amplification and filtering circuit of special signal of telecommunication |
| CN106941340A (en) * | 2017-04-09 | 2017-07-11 | 北京工业大学 | A kind of collection for improving photosignal signal to noise ratio and process circuit |
| CN108110771A (en) * | 2016-11-24 | 2018-06-01 | 刘芳 | A kind of novel active power filter filter circuit |
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2019
- 2019-12-06 CN CN201911243889.5A patent/CN110995177B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101207374A (en) * | 2006-12-21 | 2008-06-25 | 南化集团研究院 | Pre-amplifier circuit used for stroboscopic operation |
| CN203100905U (en) * | 2013-02-05 | 2013-07-31 | 天广消防股份有限公司 | Signal processing circuit of flame detector |
| CN205510002U (en) * | 2016-03-08 | 2016-08-24 | 西安理工大学 | Amplification and filtering circuit of special signal of telecommunication |
| CN108110771A (en) * | 2016-11-24 | 2018-06-01 | 刘芳 | A kind of novel active power filter filter circuit |
| CN106941340A (en) * | 2017-04-09 | 2017-07-11 | 北京工业大学 | A kind of collection for improving photosignal signal to noise ratio and process circuit |
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