CN209748513U - Switching circuit and signal acquisition system - Google Patents
Switching circuit and signal acquisition system Download PDFInfo
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- CN209748513U CN209748513U CN201920844884.7U CN201920844884U CN209748513U CN 209748513 U CN209748513 U CN 209748513U CN 201920844884 U CN201920844884 U CN 201920844884U CN 209748513 U CN209748513 U CN 209748513U
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/08—Modifications for protecting switching circuit against overcurrent or overvoltage
- H03K17/081—Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit
- H03K17/08104—Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit in field-effect transistor switches
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
- H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
- H03K17/567—Circuits characterised by the use of more than one type of semiconductor device, e.g. BIMOS, composite devices such as IGBT
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Abstract
The utility model provides a switching circuit and signal acquisition system, switching circuit includes first sub-switch, second sub-switch and voltage compensation circuit, the first end of first sub-switch is connected with external equipment as switching circuit's input, the second end is connected with the first end of second sub-switch, the second end of second sub-switch is connected with the inverting input end of operational amplifier circuit as switching circuit's output, the non inverting input end of operational amplifier circuit is connected with a power, voltage compensation circuit is connected between first sub-switch and the second sub-switch, when carrying out signal acquisition and breaking the switching circuit, under the effect of voltage compensation circuit, make the voltage between first sub-switch and second sub-switch the same with the voltage of the inverting input end of operational amplifier circuit, so that the leakage current that gets into the inverting input end of operational amplifier circuit through the second sub-switch is eliminated, and further avoid influencing the voltage that the output of operational amplifier circuit output because of this leakage current influences the signal acquisition result.
Description
Technical Field
The utility model relates to an analog signal sampling technical field particularly, relates to a switch circuit and signal acquisition system.
Background
Signal acquisition is usually implemented in an integrated circuit by a switch, which usually uses a field effect transistor (MOSFET), and due to various non-ideal factors, when the MOSFET switch is turned off, the impedance Rs from the input end to the output end of the switch is not infinite, so that when a voltage difference Vdiff exists between the input and the output of the switch, a switch leakage current Ileak related to the voltage difference Vdiff and the switch impedance Rs is introduced into the input end of the AFE. Referring to fig. 1, fig. 1 is a schematic circuit diagram of a conventional signal acquisition system. Assuming that the voltage at the input end of the switch is vin (t), the voltage at the output end of the switch, i.e., the voltage at the out-phase input end of the AFE, is vcia (t), and the voltage at the in-phase input end of the AFE is VCOM, due to the virtual short effect of the operational amplifier, vcia (t) is VCOM, i.e., the voltage at the out-phase input end of the AFE does not change, so the charge/current introduced into the out-phase input end of the AFE by the leakage current Ileak passes through the feedback capacitor CF, and directly affects the output voltage of. Ileak becomes a noise source when the input signal is charge or current, reducing the signal-to-noise ratio (SNR) of the input analog signal. In the signal acquisition stage, the magnitude of the introduced noise charge Qn is related to the acquisition time T, and the introduced noise charge is the noise voltage Vn, out of the noise charge introduced at the AFE output terminal, and therefore, it is an urgent technical problem to effectively reduce the leakage current caused by the switch.
SUMMERY OF THE UTILITY MODEL
In view of the above, an object of the present invention is to provide a switch circuit and a signal acquisition system, so as to effectively alleviate the above problems.
In order to achieve the above object, the embodiment of the present invention adopts the following technical solutions:
A switching circuit is applied to a signal acquisition system comprising an operational amplifier circuit, and comprises a first sub-switch, a second sub-switch and a voltage compensation circuit;
The first end of the first sub-switch is used as the input end of the switch circuit to be connected with external equipment, the second end of the first sub-switch is connected with the first end of the second sub-switch, the second end of the second sub-switch is used as the output end of the switch circuit and is connected with the inverting input end of the operational amplifier circuit, the non-inverting input end of the operational amplifier circuit is connected with a power supply, the voltage compensation circuit is connected between the first sub-switch and the second sub-switch so as to acquire signals and disconnect the switch circuit, namely, when the first sub switch and the second sub switch are disconnected, under the action of the voltage compensation circuit, the voltage between the first sub switch and the second sub switch is the same as the voltage of the inverting input end of the operational amplifier circuit, so that the leakage current entering the inverting input terminal of the operational amplifier circuit through the second sub-switch is eliminated.
Optionally, in the switch circuit, the voltage compensation circuit includes a first capacitor, one end of the first capacitor is connected between the second end of the first sub-switch and the first end of the second sub-switch, and the other end of the first capacitor is grounded.
Optionally, in the switch circuit, the first sub switch and the second sub switch are electronic switches, and a control end of the electronic switch is electrically connected to a controller in the signal acquisition system, so as to connect or disconnect a connection between a first end and a second end of the first sub switch and a connection between a first end and a second end of the second sub switch under the action of the controller.
Optionally, in the switch circuit, the electronic switch is formed by a single MOS transistor, or a PMOS transistor and an NMOS transistor connected in parallel, and when the electronic switch is formed by a PMOS transistor and an NMOS transistor connected in parallel, a control end of the PMOS transistor and a control end of the NMOS transistor are respectively connected to the controller, and levels of the control end of the PMOS transistor and the control end of the NMOS transistor are opposite.
Optionally, in the switch circuit, the operational amplifier circuit includes an operational amplifier and a second capacitor, one end of the second capacitor is connected to an out-phase input end of the operational amplifier and then connected to a second end of the second sub-switch as an input end of the operational amplifier circuit, the other end of the second capacitor is connected to an output end of the operational amplifier, and a non-phase input end of the operational amplifier is connected to the power supply as a non-phase input end of the operational amplifier circuit.
The utility model also provides a signal acquisition system, including fortune circuit and foretell switch circuit, switch circuit with fortune circuit connection is put.
optionally, in the signal acquisition system, the signal acquisition system further includes a controller, the first sub-switch and the second sub-switch included in the switch circuit are electronic switches, and the controller is electrically connected to the control ends of the first sub-switch and the second sub-switch respectively.
optionally, in the signal acquisition system, the signal acquisition system further includes a plurality of sensors, a plurality of switch circuits, and one operational amplifier circuit, each sensor is correspondingly connected to one switch circuit, and each switch circuit is connected to the operational amplifier circuit.
Optionally, in the signal acquisition system, the signal acquisition system further includes a plurality of sensors, a plurality of switch circuits, and a plurality of the operational amplifier circuits, and each sensor is correspondingly connected to one of the operational amplifier circuits through one of the switch circuits.
Optionally, in the signal acquisition system, the sensor includes a photosensitive device and a parasitic capacitor, and a first end of the photosensitive device and the parasitic capacitor after being connected in parallel is connected to the power supply device, and the other end of the photosensitive device is connected to the input end of the switch circuit.
The utility model provides a switching circuit and signal acquisition system, switching circuit includes first sub-switch, second sub-switch and voltage compensation circuit, the first end of first sub-switch is connected with external equipment as switching circuit's input, the second end is connected with the first end of second sub-switch, the second end of second sub-switch is connected with the inverting input end of operational amplifier circuit as switching circuit's output, the non inverting input end of operational amplifier circuit is connected with a power, voltage compensation circuit is connected between first sub-switch and the second sub-switch, when carrying out signal acquisition and breaking the switching circuit, under the effect of voltage compensation circuit, make the voltage between first sub-switch and second sub-switch the same with the voltage of the inverting input end of operational amplifier circuit, so that the leakage current that gets into the inverting input end of operational amplifier circuit through the second sub-switch is eliminated, and further avoid influencing the voltage that the output of operational amplifier circuit output because of this leakage current influences the signal acquisition result.
To make the aforementioned and other objects, features and advantages of the present invention more comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope of the present invention, and for those skilled in the art, other related drawings can be obtained according to these drawings without inventive efforts.
Fig. 1 is a schematic circuit diagram of a conventional signal acquisition system.
Fig. 2 is a schematic circuit diagram of a signal acquisition system according to an embodiment of the present invention.
Fig. 3 is another schematic circuit diagram of a signal acquisition system according to an embodiment of the present invention.
Fig. 4 is another schematic circuit diagram of a signal acquisition system according to an embodiment of the present invention.
Icon: 10-a signal acquisition system; 100-a switching circuit; 110-a voltage compensation circuit; q1-first sub-switch; q2-second sub-switch; c1 — first capacitance; 200-an operational amplifier circuit; c2 — second capacitance; a-an operational amplifier; 300-a sensor; a D-photo sensitive device; c3-parasitic capacitance.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the drawings in the embodiments of the present invention are combined below to clearly and completely describe the technical solutions in the embodiments of the present invention, and obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. The apparatus of embodiments of the present invention, generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Referring to fig. 2, in the switching circuit 100 according to an embodiment of the present invention, the switching circuit 100 is applied to a signal acquisition system 10 including an operational amplifier circuit 200, and the switching circuit 100 includes a first sub-switch Q1, a second sub-switch Q2, and a voltage compensation circuit 110.
A first terminal of the first sub-switch Q1 is connected to an external device as an input terminal of the switch circuit 100, a second terminal of the first sub-switch Q1 is connected to a first terminal of the second sub-switch Q2, a second terminal of the second sub-switch Q2 is connected to an inverting input terminal of the operational amplifier circuit 200 as an output terminal of the switch circuit 100, a non-inverting input terminal of the operational amplifier circuit 200 is connected to a power supply, and the voltage compensation circuit 110 is connected between the first sub-switch Q1 and the second sub-switch Q2.
Through the above arrangement, when signal acquisition is performed and the switching circuit 100 is turned off, that is, when the first sub-switch Q1 and the second sub-switch Q2 are turned off, under the action of the voltage compensation circuit 110, the voltage between the first sub-switch Q1 and the second sub-switch Q2 and the voltage at the inverting input terminal of the operational amplifier circuit 200 tend to be the same, so that the leakage current entering the inverting input terminal of the operational amplifier circuit 200 through the second sub-switch Q2 is eliminated, and the voltage output at the output terminal of the operational amplifier circuit 200 is prevented from being influenced by the leakage current, thereby influencing the signal acquisition result.
The first sub-switch Q1 and the second sub-switch Q2 may be electronic switches or ordinary switches.
In this embodiment, the first sub-switch Q1 and the second sub-switch Q2 are electronic switches, respectively, and a control terminal of the electronic switch is electrically connected to a controller in the signal acquisition system 10, so as to connect or disconnect the first terminal and the second terminal of the first sub-switch Q1 and the first terminal and the second terminal of the second sub-switch Q2 under the action of the controller.
The electronic switch can be composed of one or more relays, MOS tubes or triodes.
In this embodiment, the electronic switch is composed of a single MOS transistor, or a PMOS transistor and an NMOS transistor connected in parallel, and when the electronic switch is composed of a PMOS transistor and an NMOS transistor connected in parallel, a control end of the PMOS transistor and a control end (gate) of the NMOS transistor are respectively connected to the controller, and levels of the control end of the PMOS transistor and the control end of the NMOS transistor are opposite.
When the single MOS tube is used, the MOS tube can be an NMOS tube or a PMOS tube, and the control end (grid) of the MOS tube is connected with the controller.
The electronic device included in the operational amplifier circuit 200 may be a capacitor, an operational amplifier, etc., and is not limited in particular.
In this embodiment, the operational amplifier circuit 200 includes an operational amplifier a and a second capacitor C2, one end of the second capacitor C2 is connected to the out-phase input terminal of the operational amplifier a and then connected to the second terminal of the second sub-switch Q2 as the input terminal of the operational amplifier circuit 200, the other end of the second capacitor C2 is connected to the output terminal of the operational amplifier a, and the non-phase input terminal of the operational amplifier a is connected to the power supply as the non-phase input terminal of the operational amplifier circuit 200.
The voltage compensation circuit 110 may be formed by a capacitor, an external power source and/or a resistor, as long as the voltage between the first sub-switch Q1 and the second sub-switch Q2 is maintained to be the same as the voltage before the first sub-switch Q1 and the second sub-switch Q2 are not turned off after the first sub-switch Q1 and the second sub-switch Q2 are turned off.
Referring to fig. 3, in the present embodiment, the voltage compensation circuit 110 includes a first capacitor C1, one end of the first capacitor C1 is connected between the second end of the first sub-switch Q1 and the first end of the second sub-switch Q2, and the other end is grounded.
It is understood that the voltage compensation circuit 110 may also include a plurality of series or parallel capacitor devices, as long as the voltage between the first sub-switch Q1 and the second sub-switch Q2 can be made to be the same as before the first sub-switch Q1 and the second sub-switch Q2 are not turned off when the first sub-switch Q1 and the second sub-switch Q2 are turned off.
Specifically, taking the input voltage of the switching circuit 100 as vin (t) and the voltage of the power supply connected to the non-inverting input terminal of the operational amplifier circuit 200 as VCOM as an example, when the switching circuit 100 is closed, that is, when the first sub-switch Q1 and the second sub-switch Q2 are closed, the analog signal enters through the input terminal of the switching circuit 100 and is output to the out-phase input terminal of the operational amplifier circuit 200 through the first sub-switch Q1 and the second sub-switch Q2, so that the operational amplifier circuit 200 performs processing and then outputs the processed analog signal. According to the virtual short principle of the operational amplifier circuit 200, the voltage vcia (t) at the non-inverting input terminal of the operational amplifier circuit 200 is approximately equal to the voltage VCOM at the inverting input terminal, and the voltage at the center point O is approximately VCOM when the non-inverting input terminal of the operational amplifier circuit 200 is connected through the second sub-switch Q2. The capacitance value of the first capacitor C1 is Cp, which is used as a parasitic capacitor at the out-phase input terminal of the operational amplifier circuit 200, and the size of the first capacitor C1 is much smaller than that of the second capacitor C2 in the operational amplifier circuit 200, so that the operational state of the operational amplifier circuit 200 is not affected.
When the switching circuit 100 is turned off, i.e., the first sub-switch Q1 and the second sub-switch Q2 are turned off, the leakage through the second sub-switch Q2 into the out-of-phase input of the op-amp circuit 200 is greatly reduced. Specifically, when the first sub-switch Q1 and the second sub-switch Q2 are turned off, the center point O is in a high impedance state. The switch input is disconnected from the common mode input of the operational amplifier circuit 200 due to the first sub-switch Q1 and the second sub-switch Q2 being open, which has no effect on the out-of-phase input of the operational amplifier circuit 200. The voltage at the input end of the first sub-switch Q1 is vin (t), the voltage va (t) at the output end of the first sub-switch Q1, i.e. the center point O, is VCOM when the switch is just turned off due to the holding effect of the first capacitor C1, and the leakage current generated by the first sub-switch Q1 is: the voltage at the center point O is: since the turn-off resistance Rs1 of the first sub-switch Q1 is large, the leakage current Ileak1(t) of the first sub-switch Q1 approaches 0, and Δ VA, i.e., the second term on the right side in the above equation, is approximately 0. I.e., VA (t) is approximately VCOM; the voltage at the output terminal of the second sub-switch Q2, i.e., the output terminal of the switch, is the out-of-phase input terminal of the operational amplifier circuit 200, and is approximately equal to the VCOM voltage according to the virtual short principle of the operational amplifier circuit 200. Therefore, the input and output voltages of the second sub-switch Q2 are both approximately equal to VCOM, the voltage difference is small, the switch leakage current of the second sub-switch Q2 is Δ VA ≈ 0, Vdiff2 is the voltage difference across the second sub-switch, and Vdiff2 ≈ 0, then Ileak2 ≈ 0, so the leakage current introduced to the AFE input through the turn-off resistor Rs2 of the second sub-switch Q2 is approximately eliminated, and furthermore, the leakage current can be further reduced by increasing the capacitance value of the first capacitor C1.
Referring to fig. 4, on the basis of the foregoing, the present invention further provides a signal acquisition system 10, where the signal acquisition system 10 includes an operational amplifier circuit 200 and the switch circuit 100, and the switch circuit 100 is electrically connected to the operational amplifier circuit 200, and the detailed electrical connection manner of the signal acquisition system can refer to the foregoing description of the switch circuit 100.
It should be noted that, the number of the switch circuits 100 included in the signal acquisition system 10 may be one or multiple, it is understood that, when there are multiple analog signals to be acquired, there are multiple switch circuits 100 correspondingly needed, and when there are multiple switch circuits 100, the number of the operational amplifier circuits 200 needed may be one or multiple, it is understood that, when there are multiple operational amplifier circuits 200, each switch circuit 100 may be connected to one operational amplifier circuit 200, and when there are one operational amplifier circuits 200, each switch circuit 100 is respectively connected to one operational amplifier circuit 200.
Optionally, in this embodiment, the signal acquiring system 10 includes a sensor 300, a plurality of switch circuits 100, and one operational amplifier circuit 200, where each sensor 300 is correspondingly connected to one switch circuit 100, and each switch circuit 100 is connected to the operational amplifier circuit 200.
The connection between each switch circuit 100 and the operational amplifier circuit 200 is specifically that the output terminal of each switch circuit 100 is connected to the out-phase input terminal of the operational amplifier circuit 200.
In order to facilitate the signal acquisition system 10 to acquire signals, in this embodiment, the signal acquisition system 10 further includes a controller, the first sub-switch Q1 and the second sub-switch Q2 included in the switch circuit 100 are electronic switches, and the controller is electrically connected to the control terminals of the first sub-switch Q1 and the second sub-switch Q2, respectively.
The sensor 300 may be, but not limited to, a sound sensor, a temperature sensor, an angle sensor, a pressure sensor, a position sensor, or the like, and is not particularly limited herein.
Taking the signal collecting system 10 as a fingerprint collecting system, the sensor 300 further includes a photosensitive device D and a parasitic capacitor C3 as an example, wherein a first end of the photosensitive device D and the parasitic capacitor C3 connected in parallel is connected to a power supply device, and the other end is connected to an input end of the switch circuit 100.
Specifically, when the sensor 300 includes the light sensing device D and the parasitic capacitor C3, the sensor 300 generates the charge signal Qs according to the intensity of external light during a certain time. When the first sensor 300 in fig. 4 is operated, the valid signal Qs1 is transmitted to the operational amplifier circuit 200 for processing and outputting, and at this time, the signals Qs (n) of the other sensors 300 are kept at the voltage of the respective parasitic capacitors C3, and the other switches are closed, which has no influence on the operational amplifier circuit 200. The present invention eliminates the leakage current in the middle switching circuit 100, and therefore, even when the number of the sensors 300 is large, the reduction of the signal-to-noise ratio due to the switch leakage current is also eliminated.
The utility model provides a switching circuit 100 and signal acquisition system 10, switching circuit 100 includes first subswitch Q1, second subswitch Q2 and voltage compensation circuit 110, the first end of first subswitch Q1 is connected with external equipment as the input of switching circuit 100, the second end is connected with the first end of second subswitch Q2, the second end of second subswitch Q2 is as the output of switching circuit 100 and is connected with the inverting input of operational amplifier circuit 200, the noninverting input of operational amplifier circuit 200 is connected with a power supply, voltage compensation circuit 110 is connected between first subswitch Q1 and second subswitch Q2, so that when signal acquisition and with switching circuit 100 disconnection, under the effect of voltage compensation circuit 110, make the voltage between first subswitch Q1 and second subswitch Q2 the voltage of inverting input of operational amplifier circuit 200 the same, so that the reverse phase leakage current that gets into the inverting input of operational amplifier circuit 200 through second subswitch Q2 is eliminated, thereby avoiding the influence of the leakage current on the voltage output by the output end of the operational amplifier circuit 200 and the signal acquisition result.
It is noted that, herein, relational terms such as first and second, and the like may be 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. Also, 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 an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. A switching circuit is applied to a signal acquisition system comprising an operational amplifier circuit and is characterized in that the switching circuit comprises a first sub-switch, a second sub-switch and a voltage compensation circuit;
The first end of the first sub-switch is used as the input end of the switch circuit to be connected with external equipment, the second end of the first sub-switch is connected with the first end of the second sub-switch, the second end of the second sub-switch is used as the output end of the switch circuit and is connected with the inverting input end of the operational amplifier circuit, the non-inverting input end of the operational amplifier circuit is connected with a power supply, the voltage compensation circuit is connected between the first sub-switch and the second sub-switch so as to acquire signals and disconnect the switch circuit, namely, when the first sub switch and the second sub switch are disconnected, under the action of the voltage compensation circuit, the voltage between the first sub switch and the second sub switch is the same as the voltage of the inverting input end of the operational amplifier circuit, so that the leakage current entering the inverting input terminal of the operational amplifier circuit through the second sub-switch is eliminated.
2. the switch circuit of claim 1, wherein the voltage compensation circuit comprises a first capacitor, one end of the first capacitor is connected between the second end of the first sub-switch and the first end of the second sub-switch, and the other end of the first capacitor is grounded.
3. The switch circuit according to claim 1, wherein the first and second subswitches are electronic switches, and a control terminal of the electronic switch is electrically connected to a controller in the signal acquisition system, so as to connect or disconnect a first terminal and a second terminal of the first subswitch and a first terminal and a second terminal of the second subswitch under the action of the controller.
4. The switch circuit of claim 3, wherein the electronic switch is composed of a single MOS transistor or a parallel connection of a PMOS transistor and an NMOS transistor, and when the electronic switch is composed of a PMOS transistor and an NMOS transistor, the control terminal of the PMOS transistor and the control terminal of the NMOS transistor are respectively connected to the controller, and the control terminal of the PMOS transistor and the control terminal of the NMOS transistor have opposite levels.
5. The switch circuit according to claim 1, wherein the operational amplifier circuit comprises an operational amplifier and a second capacitor, one end of the second capacitor is connected to an out-phase input terminal of the operational amplifier and then serves as an input terminal of the operational amplifier circuit to be connected to a second terminal of the second sub-switch, the other end of the second capacitor is connected to an output terminal of the operational amplifier, and a non-phase input terminal of the operational amplifier serves as a non-phase input terminal of the operational amplifier circuit to be connected to the power supply.
6. A signal acquisition system comprising an operational amplifier circuit and a switching circuit as claimed in any one of claims 1 to 5, the switching circuit being connected to the operational amplifier circuit.
7. The signal acquisition system according to claim 6, further comprising a controller, wherein the first and second subswitches included in the switch circuit are electronic switches, respectively, and the controller is electrically connected to control terminals of the first and second subswitches, respectively.
8. The signal acquisition system according to claim 6, further comprising a plurality of sensors, a plurality of switch circuits, and one of the operational amplifier circuits, wherein each sensor is correspondingly connected to one of the switch circuits, and each of the switch circuits is connected to the operational amplifier circuit.
9. The signal acquisition system of claim 6, further comprising a plurality of sensors, a plurality of switching circuits, and a plurality of said operational amplifier circuits, wherein each sensor is correspondingly connected to one of said operational amplifier circuits through one switching circuit.
10. The signal acquisition system according to claim 8 or 9, wherein the sensor comprises a light sensing device and a parasitic capacitor, and a first end of the light sensing device and the parasitic capacitor after being connected in parallel is connected with a power supply device, and the other end of the light sensing device and the parasitic capacitor is connected with the input end of the switching circuit.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811519946.3A CN109379068A (en) | 2018-12-12 | 2018-12-12 | Switching circuit and signal acquiring system |
| CN2018220896453 | 2018-12-12 | ||
| CN2018115199463 | 2018-12-12 | ||
| CN201822089645 | 2018-12-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209748513U true CN209748513U (en) | 2019-12-06 |
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| CN201910487797.5A Pending CN110166030A (en) | 2018-12-12 | 2019-06-05 | Switching circuit and signal acquiring system |
| CN201920844884.7U Active CN209748513U (en) | 2018-12-12 | 2019-06-05 | Switching circuit and signal acquisition system |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201910487797.5A Pending CN110166030A (en) | 2018-12-12 | 2019-06-05 | Switching circuit and signal acquiring system |
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| CN106411303A (en) * | 2016-09-16 | 2017-02-15 | 天津大学 | Anti-creeping MOS switch structure applicable to integrated circuit |
| CN107332563A (en) * | 2017-05-31 | 2017-11-07 | 苏州真感微电子科技有限公司 | Reduce the circuit of switching capacity input current and the method for sampling of switching capacity |
| CN108847173B (en) * | 2018-06-29 | 2020-09-29 | 深圳市华星光电半导体显示技术有限公司 | Common voltage feedback compensation circuit and method and flat panel display device |
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| CN110166030A (en) | 2019-08-23 |
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