CN208207583U - Signal acquisition circuit - Google Patents

Abstract

The utility model discloses a kind of signal acquisition circuits, belong to environmental testing.Signal acquisition circuit includes: Signal interface module；Signal interface module is coupled with the first power end, the first output and ground respectively, and Signal interface module is configured at least three input terminals, at least three input terminals include: first input end, the second input terminal and third input terminal, first input end is coupled with the first power end, second input terminal is coupled with the first output end, and third input terminal is coupled with ground terminal；Second input terminal is used for when first input end and the second input terminal are shorted, loaded switches amount measured signal；Second input terminal is used for when third input terminal and the second input terminal are shorted, loading simulation amount electric current measured signal；Second input terminal is used for when first input end and third input terminal are not shorted with the second input terminal, loading simulation amount voltage measured signal.The signal acquisition circuit effectively improves the utilization rate of signal acquisition circuit.

Description

Signal acquisition circuit

Technical field

The utility model relates to environmental testing, in particular to a kind of signal acquisition circuit.

Background technique

In the controls, the signal of transmission may include analog quantity and switching value, wherein analog quantity refers in certain model The amount of interior consecutive variations is enclosed, such as: temperature consecutive variations, the temperature value can be analog quantity, pressure between 0 to 100 degree Celsius Power consecutive variations, the pressure value can be analog quantity between from 0 to 10 megapascal；Switching value only has two states, such as: it is common The switching value of switch has on state and off-state, and the switching value of relay has closed state and opening state.

In the related technology, it when detecting analog quantity and switching value, needs to acquire using different signal acquisition circuits Analog signals and on-off model, that is to say, for a certain signal acquisition circuit, which can only acquire mould Analog quantity signal or on-off model cause the utilization rate of signal acquisition circuit lower.

Utility model content

The utility model provides a kind of signal acquisition circuit, can solve the utilization of signal acquisition circuit in the related technology The lower problem of rate.The technical solution is as follows:

In a first aspect, providing a kind of signal acquisition circuit, the signal acquisition circuit includes: Signal interface module；

The Signal interface module is coupled with the first power end, the first output and ground respectively, and the signal connects Mouth mold block is configured at least three input terminals, and at least three input terminal includes: first input end, the second input terminal and third Input terminal, the first input end are coupled with first power end, and second input terminal is coupled with first output end, The third input terminal is coupled with the ground terminal；

Second input terminal is used for when the first input end and second input terminal are shorted, and loaded switches amount waits for Survey signal；

Second input terminal is used for when the third input terminal and second input terminal are shorted, loading simulation amount electricity Flow measured signal；

Second input terminal is used to not input with described second in the first input end and the third input terminal When end is shorted, loading simulation amount voltage measured signal.

Optionally, the signal acquisition circuit further include: analog-to-digital conversion module；

The analog-to-digital conversion module is coupled with first output end and processing component respectively, and the analog-to-digital conversion module is used In the signal inputted by first output end is converted to digital signal, and to the processing component input number letter Number, the processing component is for according to the digital signal detecting the measured signal.

Optionally, the signal acquisition circuit further include: voltage transformation module；

The voltage transformation module is coupled with first output end and the analog-to-digital conversion module respectively, and the voltage turns Mold changing block is used to zoom in and out processing to the amplitude of the signal inputted by first output end, and to the analog-to-digital conversion module Input scaled treated signal.

Optionally, the voltage transformation module includes: voltage conversion chip；

The voltage conversion chip includes: the first reference signal input pin, the second reference signal input pin, benchmark electricity Signal input tube foot and second output terminal are pressed, the first reference signal input pin is defeated by first output end for receiving The signal entered, the voltage conversion chip is used for according to the signal inputted by first output end, from second reference Second reference signal of signal input tube foot, and, the reference voltage signal from the reference voltage signal input pin is right Processing is zoomed in and out by the signal that first output end inputs, and to after the second output terminal input scaled processing Signal.

Optionally, the voltage transformation module includes: operational amplifier.

Optionally, the voltage transformation module is also coupled with power module, and the power module is used to turn to the voltage Change the mold block input reference voltage signal.

Optionally, the power module includes: power convert submodule and voltage follow submodule；

The power convert submodule is coupled with first power end and the voltage follow submodule respectively, the electricity Source transform subblock is used to be converted to the voltage signal from first power end voltage signal of default amplitude；

The voltage follow submodule is also coupled with the voltage transformation module, and the voltage follow submodule is used for institute Voltage signal after stating the input conversion of voltage transformation module full width.

Optionally, the signal acquisition circuit further include: first voltage follows module；

The first voltage follows module to couple respectively with first output end and the voltage transformation module, and described One voltage follow module is used to input the input signal inputted by first output end to the voltage transformation module full width.

Optionally, the signal acquisition circuit further include: second voltage follows module；

The second voltage follows module to couple respectively with the voltage transformation module and the ground terminal, second electricity Pressure follows module for inputting the ground signalling from the ground terminal to the voltage transformation module full width.

Optionally, the signal acquisition circuit includes: multiple Signal interface modules, the signal acquisition circuit further include: Channel switching module and channel control module；

The channel switching module is coupled with the channel control module and each Signal interface module respectively, the channel Switching module is used under the control signal from the channel control module, is inputted to the output end of the channel switching module Signal from echo signal interface module, the echo signal interface module are to control described in the multiple Signal interface module Module indicated by signal processed.

Optionally, the channel control module includes: the multiple switch submodule being arranged successively, and the control signal includes The output signal of the multiple switch submodule.

Optionally, the switch submodule includes: toggle switch.

Optionally, pull-up electricity is in series between the first input end of the Signal interface module and first power end Resistance；

Pull down resistor is in series between the third input terminal and the ground terminal of the Signal interface module.

Technical solution provided by the utility model has the benefit that

Signal acquisition circuit provided by the utility model, the signal acquisition circuit include: Signal interface module, which connects Mouth mold block is configured at least three input terminals, is configured by the connection type to three input terminals, it can be achieved that difference The acquisition of the signal of type, relative to the relevant technologies, which can either realize the acquisition of switch amount signal, also It can be realized the acquisition to analog quantity current signal and analog quantity voltage signal, effectively improve the utilization of signal acquisition circuit Rate.

Detailed description of the invention

It, below will be to required in embodiment description in order to illustrate more clearly of the technical scheme in the embodiment of the utility model Attached drawing to be used is briefly described, it should be apparent that, the accompanying drawings in the following description is only some realities of the utility model Example is applied, it for those of ordinary skill in the art, without creative efforts, can also be according to these attached drawings Obtain other attached drawings.

Fig. 1 is a kind of structural schematic diagram of signal acquisition circuit provided by the embodiment of the utility model；

Fig. 2 is the structural schematic diagram of another signal acquisition circuit provided by the embodiment of the utility model；

Fig. 3 is the structural schematic diagram of another signal acquisition circuit provided by the embodiment of the utility model；

Fig. 4 is a kind of structural schematic diagram of analog-to-digital conversion module provided by the embodiment of the utility model；

Fig. 5 is the structural schematic diagram of another signal acquisition circuit provided by the embodiment of the utility model；

Fig. 6 is a kind of structural schematic diagram of voltage transformation module provided by the embodiment of the utility model；

Fig. 7 is a kind of schematic diagram of internal structure of voltage conversion chip provided by the embodiment of the utility model；

Fig. 8 is the structural schematic diagram of another signal acquisition circuit provided by the embodiment of the utility model；

Fig. 9 is the structural schematic diagram of another signal acquisition circuit provided by the embodiment of the utility model；

Figure 10 is a kind of structural schematic diagram of power module provided by the embodiment of the utility model；

Figure 11 is the structural schematic diagram of another signal acquisition circuit provided by the embodiment of the utility model；

Figure 12 is that a kind of first voltage provided by the embodiment of the utility model follows module and second voltage to follow module Structural schematic diagram；

Figure 13 is the structural schematic diagram of another signal acquisition circuit provided by the embodiment of the utility model；

Figure 14 is a kind of structural schematic diagram of channel switching module provided by the embodiment of the utility model；

Figure 15 is a kind of structural schematic diagram of channel control module provided by the embodiment of the utility model.

Specific embodiment

It is practical new to this below in conjunction with attached drawing to keep the purpose of this utility model, technical solution and advantage clearer Type embodiment is described in further detail.

Fig. 1 is a kind of structural schematic diagram of signal acquisition circuit provided by the embodiment of the utility model, with reference to Fig. 1, the letter Number Acquisition Circuit may include: Signal interface module 10.

The Signal interface module 10 is coupled with the first power end VGH1, the first output end OUT1 and ground terminal VGL respectively, and The Signal interface module 10 is configured at least three input terminals, which includes: first input end IN1, second Input terminal IN2 and third input terminal IN3, first input end IN1 are coupled with the first power end VGH1, second input terminal IN2 For loading measured signal, and the second input terminal IN2 is coupled with the first output end OUT1, the third input terminal IN3 and ground connection Hold VGL coupling.Optionally, the amplitude of the voltage signal from first power end VGH1 can be 5 volts (V).

Be shorted in first input end IN1 and the second input terminal IN2 (such as: conducting wire can be passed through or jump cap is shorted) when, it should Second input terminal IN2 is used for loaded switches amount measured signal；Such as: it is shorted in first input end IN1 and the second input terminal IN2 When, if switching value measured signal is when opening, to be equivalent to open circuit between the first power end VGH1 and the first output end OUT1, first is defeated The current potential of signal of outlet OUT1 output be in the second current potential, if switching value measured signal is when closing, the first power end VGH1 with There are connecting path between first output end OUT1, the signal of the first output end OUT1 output is high potential signal, by this One output end OUT1 exports corresponding high potential signal or low-potential signal, can be realized and adopts to the switching value measured signal Collection.

When third input terminal IN3 and the second input terminal IN2 is shorted, the second input terminal IN2 is for loading simulation amount electricity Flow measured signal；Such as: when third input terminal IN3 and the second input terminal IN2 is shorted, if being loaded on the second input terminal IN2 Analog quantity electric current measured signal, there are connecting path, the analog quantity electric currents of load between the first output end OUT1 and ground terminal VGL Measured signal can generate pressure drop on the resistance between the second input terminal IN2 and ground terminal VGL, and pass through the first output end OUT1 The corresponding simulation numerical quantity of the pressure drop is exported, the acquisition to the analog quantity electric current measured signal can be realized.

When first input end IN1 and third input terminal IN3 are not shorted with the second input terminal IN2, second input terminal IN2 is used for loading simulation amount voltage measured signal, that is to say, is not present between first input end IN1 and the second input terminal IN2 Connection relationship, and there is no when connection relationship between third input terminal IN3 and the second input terminal IN2, which uses In loading simulation amount voltage measured signal.Such as: first input end IN1 and third input terminal IN3 not with the second input terminal When IN2 is shorted, if the loading simulation amount voltage measured signal on the second input terminal IN2, the analog quantity voltage measured signal can lead to It crosses the first output end OUT1 directly to export, and then realizes the signal acquisition to the analog quantity voltage measured signal.

Optionally, according to the needs of signal acquisition scene, signal acquisition circuit may include multiple Signal interface modules 10. Illustratively, referring to FIG. 2, signal acquisition circuit includes 4 Signal interface modules 10, each Signal interface module 10 is configured with four A input terminal, four input terminals are respectively first input end IN1, the second input terminal IN2, third input terminal IN3 and the 4th defeated Enter to hold IN4.Wherein, it can be in series with pull-up resistor R11 between first input end IN1 and the first power end VGH1, the pull-up Resistance R11 is used to the current potential of first input end IN1 remaining high potential.And first power end VGH1 can pass through voltage-stabiliser tube U11 is grounded (refer to and connect with ground terminal VGL).Second input terminal IN2 for loading measured signal, and the second input terminal IN2 with First output end OUT1 coupling.It can be in series with pull down resistor R12 between the third input terminal IN3 and ground terminal VGL, the drop-down Resistance R12 is used to the current potential of third input terminal IN3 remaining low potential.4th input terminal IN4 is idle port.

When acquiring measured signal, if measured signal is switching value measured signal, jump cap may be used by first input end IN1 is shorted with the second input terminal IN2；If measured signal is analog quantity current signal, jump cap may be used by the second input End IN2 and third input terminal IN3 is shorted；If measured signal is analog quantity voltage signal, it is defeated jump cap can be placed on second Enter to hold on IN2 and the 4th input terminal IN4, at this point, loading since the 4th input terminal IN4 is idle port in the second input terminal IN2 On measured signal can directly be exported by the first output end OUT1.

In conclusion signal acquisition circuit provided by the utility model, which includes: signaling interface mould Block, the Signal interface module are configured at least three input terminals, are configured by the connection type to three input terminals, can Realize the acquisition to different types of signal, relative to the relevant technologies, which can either realize that switch amount is believed Number acquisition, additionally it is possible to realize acquisition to analog quantity current signal and analog quantity voltage signal, effectively improve signal and adopt The utilization rate of collector.

After completing signal acquisition, collected signal can be sent to processing component, make processing component according to collecting Signal detected to measured signal, to realize detection to measured signal.Illustratively, which can be used In environment measuring (such as: for detect light emitting diode (Light-Emitting Diode, LED) show product peripheral ring Border), by being acquired to the coherent signal in environment, it can be realized the detection to environmental parameter, such as: acquisition can be passed through Voltage drop on thermistor, to realize the detection to temperature.

But since the signal that Signal interface module 10 exports is analog signal, and processing component usually can only identify Digital signal, therefore, before using processing component detection signal, it is also necessary to the analog signal for exporting Signal interface module 10 Be converted to digital signal.

In a kind of achievable mode, analog-to-digital conversion interface is configured on processing component, at this point, can be by Signal interface module The signal of 10 outputs is input to the analog-to-digital conversion interface, in the simulation that the inside of the processing component acquires Signal interface module 10 Signal is converted to digital signal, and detects to the digital signal after conversion.

In the achievable mode of another kind, Analog-digital Converter interface is not configured on processing component, at this point, please referring to figure 3, which can also include: analog-to-digital conversion module 20, the analog-to-digital conversion module 20 respectively with Signal interface module Input terminal (being not shown in Fig. 3) coupling of 10 the first output end OUT1 and processing component, which is used for will Digital signal is converted to by the signal that the first output end OUT1 is inputted, and inputs digital signal to the input terminal of processing component, So that processing component is detected to measured signal according to the digital signal.

Optionally, which may include modulus conversion chip, such as: the analog-to-digital conversion module 20 can be with For the modulus conversion chip of 10,12 or 16 bits, and when the number of bits of the analog-to-digital conversion module 20 is higher, to simulation The conversion accuracy of signal is higher, correspondingly, the detection accuracy of signal is higher.Illustratively, when analog-to-digital conversion module 20 is 16 bits When the modulus conversion chip of position, detection accuracy can reach one thousandth.The processing component can for micro-control unit (English: Microcontroller Unit；Referred to as: MCU, also referred to as: single-chip microcontroller), which can pass through Serial Peripheral Interface (SPI) Digital signal after conversion is sent to MCU by (Serial Peripheral Interface, SPI), to realize between the two Communication.

In a kind of achievable mode, which can support negative pressure to acquire, and the chip interior can integrate There is programmable gain amplifier (Pmgrammable Gain Amplifier, PGA), it can be right inside modulus conversion chip Signal amplifies, and when so that being detected according to the amplified signal, can obtain bigger detection accuracy.Illustratively, Fig. 4 is a kind of structural schematic diagram of modulus conversion chip, as shown in figure 4, the connection type of each pin of the modulus conversion chip is such as Under:

Positive analog power interface pin AVDD is connect by pull-up resistor R21 with the first power end VGH1, and the anode Analog power interface pin AVDD also passes through filter capacitor C21 and capacitor C22 ground connection in parallel, cathode analog power interface pin AVSS ground connection.

Positive digital power interface pin DVDD is connect with third power end VGH3, and digital power interface pin DVDD Also by filter capacitor C23 and capacitor C24 ground connection in parallel.Cathode digital power interface pin DGND ground connection.Wherein, coming from should The amplitude of the voltage of third power end VGH3 can be 3.3V.

The power end connection of positive reference signal pin REFP and 2.5V, negative reference signal pin REFN ground connection, and the positive ginseng It examines signal pin REFP to connect by capacitor C25 with the negative reference signal pin REFN, and the negative reference signal pin REFN is also It is connect with clock signal terminal CLK.

Positive input pin AINP is used to receive by the signal of the first output end OUT1 input of Signal interface module 10, this is just Input pin AINP is connected with negative input pin AINN by capacitor C28, and positive input pin AINP is grounded by capacitor C26, Negative input pin AINN is grounded by capacitor C27.By the signal of positive input pin AINP input and by the negative input pin The signal of AINN input may make up the differential signal for being input to analog-to-digital conversion module 20, be turned by the input mode of difference to modulus Mold changing block 20 provides the effect that common mode inhibition may be implemented in input signal, to inhibit the interference component in input signal, Jin Erti The accuracy of high RST detection.

Optionally, negative input pin AINN can also pass through two concatenated pull-up resistors and reference voltage signal V0_ AIN connection.The reference voltage signal is used to limit the maximum value for the signal for being input to modulus conversion chip, in modulus conversion chip To analog signal carry out mode conversion when, can according to the reference voltage signal, by the first output end OUT1 input analog signal, And the range (i.e. by the digital quantity represented by all bits of modulus conversion chip) of modulus conversion chip, by analog signal Be converted to digital signal.Wherein, the transfer principle of modulus conversion chip are as follows: assuming that analog-converted chip is 16 bits, this 16 The corresponding digital quantity of bit is 65536, reference voltage signal 2.5V, 2.5V can be divided into 65536 equal parts, often The corresponding voltage value of a equal part are as follows: 2.5/65536=0.0000381V, if analog signal is nV, the digital signal after conversion For n/0.0000381V.

Reseting pin RST can be connect by resistance R22 with reset signal end RST_1146, and resistance R22 and reset One end of pin RST connection can also be grounded by capacitor C29.Also, and the other end of resistance R22 can pass through pull-up electricity Resistance R23 is connect with third power end VGH3.Meanwhile enabling signal pin SRT is also connect with reset signal end RST_1146.

In addition, serial clock input pin SCLK can be connect with serial input signals end SPI3_CLK；Serial data is defeated Entering pin DIN can connect with input serial data signal end SPI3_MOSI；Data preparation output pin DRDY can be with output DRDY# connection is held, is used for processing component input data ready signal；Serial data out pin DOUT/DRDY can be with Output end SPI3_MISO connection is used to input the digital signal after conversion to processing component；Chip selection signal input pin CS can To be connect with output end SPI3_NSS.

Further, since reference voltage signal is used to limit the maximum value for the signal for being input to modulus conversion chip, and Amplitude due to being input to the voltage source of the first input end IN1 of signal acquisition circuit is generally higher than the maximum value, it is inciting somebody to action Before being input to analog-to-digital conversion module 20 by the analog signal that the first output end OUT1 is exported, need to reduce the width of the analog signal Value makes the amplitude after reducing no more than the maximum value, therefore, referring to FIG. 5, can also include: electricity in the signal acquisition circuit Press conversion module 30.The voltage transformation module 30 respectively with the first output end OUT1, the analog-to-digital conversion mould of Signal interface module 10 Block 20 and second source end VGH2 coupling, the voltage transformation module 30 is for the width to the signal inputted by the first output end OUT1 Value zooms in and out processing, and inputs scaled treated signal to analog-to-digital conversion module 20.Optionally, the voltage transformation module 30 function can be realized by voltage conversion chip or operational amplifier, and the amplitude of the voltage signal of second source end VGH2 can Think 12V.

Illustratively, when realizing the function of the voltage transformation module 30 by voltage conversion chip, which can be with Support the single supply input of 12V, and can realize zoom function in portion in the chip, can be avoided because circuit ambient parameters not With causing signal difference excessive, and the gain accuracy of its zoom function can reach 0.01%.In a kind of achievable mode, the electricity Press the connection type of each pin of conversion chip referring to FIG. 6, the connection type of each pin is as follows:

First reference signal input pin REF is used to receive the signal inputted by the first output end OUT1, and second with reference to letter Number input pin SEN is for accessing ground signalling.

Cathode power supply end pipe foot V+ is connect with second source end VGH2, and cathode power supply end pipe foot V+ also passes through parallel connection Filter capacitor C31 and filter capacitor C32 ground connection, negative power supply pin V- ground connection.

Positive input pin IN+ is connect with reference voltage signal V0_AIN, reversed input pin IN- and the voltage conversion chip Output pin OUT connection, output pin OUT is used to input scaled treated signal to analog-to-digital conversion module 20.It can Selection of land, output pin OUT can pass through the positive input pin AINP connection of resistance R31 and modulus conversion chip.

The principle that the voltage conversion chip zooms in and out processing to the amplitude of signal can be with are as follows: according to from first with reference to believing The first reference signal of number input pin REF, the second reference signal from the second reference signal input pin SEN, and, come From the reference voltage signal V0_AIN of positive input pin IN+, processing zoomed in and out to the first reference signal, and to output pin Scaled treated the signal of OUT input.Illustratively, it is assumed that the amplitude of the first reference signal is V1, the width of the second reference signal Value is V2, and the minification of voltage conversion chip is M, and the amplitude of reference voltage signal V0_AIN is V0, then converts through the voltage Chip is to amplitude Vi=(V1+V2)/M+V0 after signal diminution.

Further, the internal structure of the voltage conversion chip is referring to FIG. 7, as can be seen that voltage conversion chip master It to be made of operational amplifier, and the inverting input terminal of the operational amplifier is connected by resistance R32 and reversed input pin IN- It connects, which also passes through resistance R33 and connect with the second reference signal input pin SEN, the positive of the operational amplifier Input terminal is connect by resistance R34 with positive input pin IN+, and the normal phase input end is defeated by resistance R35 and the first reference signal Enter pin REF connection.It can be realized by the resistance value of setting resistance R32, resistance R33, resistance R34 and resistance R35 to minification The setting of (or amplification factor), such as: when the amplitude of reference voltage signal is 2.5V, and due to being input to signal acquisition circuit When the amplitude of the voltage source of first input end IN1 is 5V, at this point, according to actual needs, can will be inputted by the first output end OUT1 Signal reduce 10 times, then can be by resistance R32 and resistance R34 so as to be input to the signal of modulus conversion chip no more than 2.5V Resistance value be set as 10000 ohm, set 100000 ohm for the resistance value of resistance R33 and resistance R35, make voltage conversion chip Minification be 10, by 10 times of the amplitude of signal input by the first output end OUT1 diminution.

It should be noted that when the amplitude of the signal inputted by the first output end OUT1 is reduced 10 times by voltage conversion chip When, its received analog signal can be amplified 4 times inside analog-to-digital conversion module 20, so that the amplitude of amplified signal is closer The amplitude of reference voltage signal, and then obtain higher detection accuracy.

When realizing the function of the voltage transformation module 30 by operational amplifier, the input terminal of operational amplifier and output The connection type at end please refers to the connection type of each pin of voltage conversion chip, and details are not described herein again.

Further, referring to FIG. 8, the signal acquisition circuit can also include: power module 40, which is used In to 20 input reference voltage signal of voltage transformation module 30 and analog-to-digital conversion module, so that voltage transformation module 30 is according to benchmark Voltage signal zooms in and out processing and analog-to-digital conversion module 20 to the amplitude of the input signal inputted by the first output end OUT1 Digital signal is converted analog signals into according to the reference voltage signal.

Optionally, referring to FIG. 9, the power module 40 may include: power convert submodule 401 and voltage follow submodule Block 402.The power convert submodule 401 is coupled with the first power end VGH1 and voltage follow submodule 402 respectively, which turns Submodule 401 is changed for the voltage signal from the first power end VGH1 to be converted to the voltage signal of default amplitude；The voltage Follow submodule 402 also to couple with voltage transformation module 30 and analog-to-digital conversion module 20, the voltage follow submodule 402 be used for Voltage signal after voltage transformation module 30 and the input conversion of 20 full width of analog-to-digital conversion module, for the voltage transformation module 30 and is somebody's turn to do Analog-to-digital conversion module 20 provides reference voltage signal.

Illustratively, referring to FIG. 10, the power convert submodule 401 may include voltage-reference, the voltage-reference It can be used for be converted to signal and the output of default amplitude from the voltage signal of the first power end VGH1, such as: it can will come from The voltage signal of the 5V of first power end VGH1 is converted to signal and the output of 2.5V；The voltage follow submodule 402 can wrap Operational amplifier is included, which can be used for exporting the letter after being converted by voltage-reference to 30 full width of voltage transformation module Number, such as: the 2.5V signal after being converted to the output of 30 full width of voltage transformation module by voltage-reference.

Wherein, the input pin I of the voltage-reference is connect with the first power end VGH1, and the input of the voltage-reference Pin I passes through capacitor C41 and capacitor C42 ground connection in parallel.The same phase of the output pin O of the voltage-reference and operational amplifier Input terminal connection, and the output pin O of the voltage-reference also passes through capacitor C43, capacitor C44 and capacitor C45 ground connection in parallel. The ground pin G of the voltage-reference is grounded.Since the output voltage precision of the voltage-reference can achieve 0.2%, and have There is preferable temperature drift performance, can be improved the precision of the reference voltage signal of output, and then raising pair using the voltage-reference The detection accuracy of signal.

Signal output of the output end of the operational amplifier after resistance R41 will be converted by voltage-reference, the operation are put The inverting input terminal of big device is connect with one end of resistance R41 output signal, the positive supply input terminal of the operational amplifier and the Two power end VGH2 connections, and the positive supply input terminal also passes through capacitor C46 and capacitor C47 ground connection in parallel.The operation amplifier The negative supply input end grounding of device.

It should be noted that the function when analog-to-digital conversion module 20 is realized by modulus conversion chip, and voltage transformation module When 30 function is realized by voltage conversion chip, voltage follow submodule 402 is used for the negative input pin to modulus conversion chip AINN input reference voltage signal, and voltage follow submodule 402 is used to input to the positive input pin IN+ of voltage conversion chip Reference voltage signal, and, which is used for the positive input pin AINP input signal to modulus conversion chip, by In positive input pin AINP and the receivable signal amplitude range of negative input pin AINN be 0-5V.Meanwhile modulus conversion chip Need to meet two operating conditions: (1) Vcm+ADCin/2<4.9V, (2) Vcm-ADCin/2>0.1V, wherein ADCin when work For the signal inputted by positive input pin AINP, Vcm is the reference voltage signal inputted by negative input pin AINN.According to above-mentioned Known to two operating conditions: when the amplitude range of signal input by the first output end OUT1 is 0-5V, modulus conversion chip PGA gain be 4, and by positive input pin AINP input signal amplitude range be 0-2V when, the amplitude model of reference voltage signal Enclosing should be in 1.1-3.9V.In view of this, finding during the test: if the voltage after directly converting power convert submodule 401 It is input to voltage transformation module 30 and analog-to-digital conversion module 20, in signal acquisition process, when voltage value reaches 4V or so Shi Gen The value for the digital signal being converted to according to modulus conversion chip can be less than normal, that is to say, occurs leakage of current in circuit, but It is electricity after being converted by voltage follow submodule 402 to voltage transformation module 30 and the input of 20 full width of analog-to-digital conversion module When pressing signal, it can solve the problems, such as that the leakage of current causes the value for the digital signal being converted to less than normal, therefore, by circuit The accuracy of signal detection can be improved in middle setting voltage follow submodule 402.

Further, due to the signal that is inputted from positive input pin AINP and can from the signal that negative input pin AINN is inputted The differential signal for being input to modulus conversion chip is constituted, and the PGA inside modulus conversion chip amplifies the differential signal When, preferable common mode inhibition effect can be reached when its input impedance is in 10 ohms.Therefore, Figure 11 is please referred to, it should Signal acquisition circuit can also include: that first voltage follows module 50, which follows module 50 to export respectively with first Hold OUT1 and voltage transformation module 30 to couple, the first voltage follow module 50 for the input of 30 full width of voltage transformation module by The input signal of first output end OUT1 input, with reduce because be routed it is too long caused by impedance to the shadow of common mode inhibition effect It rings.Such as: it is defeated to the first reference signal input pin REF full width of voltage conversion chip that first voltage follows module 50 can be used for Enter the input signal inputted by the first output end OUT1.

Correspondingly, signal acquisition circuit can also include: that second voltage follows module 60 please continue to refer to Figure 11, this Two voltage follow modules 60 are coupled with voltage transformation module 30 and ground terminal VGL respectively, second voltage follow module 60 for 30 full width of voltage transformation module inputs the ground signalling from ground terminal VGL.Such as: first voltage follow module 50 can be used for Second reference signal input pin SEN full width of voltage conversion chip inputs the ground signalling.

Illustratively, which follows module 50 and the second voltage that module 60 is followed to may each comprise operation amplifier Device, the first voltage follow module 50 and the second voltage that the structural schematic diagram of module 60 is followed to please refer to Figure 12.Optionally, should First voltage follows module 50 and the second voltage to follow the operational amplifier in module 60 that the single supply of 12V can be supported to supply Electricity, and the input of the operational amplifier can be rail-to-rail input mode (can export input signal full width), to reduce temperature Drift.

Please continue to refer to Figure 12, which follows module 50 and the second voltage to follow the operation amplifier in module 60 The inverting input terminal of device can be connect with the output end of the operational amplifier.The non-inverting input terminal of the operational amplifier is for receiving Input signal, the input signal can input the non-inverting input terminal by a resistance.And first voltage follows operation in module 50 The non-inverting input terminal of amplifier is used to receive the signal inputted by the first output end OUT1, and second voltage follows operation in module 60 The non-inverting input terminal of amplifier is grounded.Also, the non-inverting input terminal of the operational amplifier also passes through capacitor and resistance in parallel and connects Ground.The first voltage follow module 50 and the second voltage follow the positive supply input terminal of operational amplifier in module 60 with The VGH2 connection of second source end, which follows module 50 and the second voltage follows the operational amplifier in module 60 Negative supply input terminal is grounded.Further, first voltage follows the positive supply input terminal of the operational amplifier of module 50 may be used also To pass through two capacity earths in parallel.

It should be noted that including operational amplifier when first voltage follows module 50 and second voltage to follow module 60 When, mistake which follows module 50 and second voltage to follow the setting of module 60 that can also eliminate operational amplifier itself Difference can further increase the precision of signal detection.

In a kind of achievable mode, signal acquisition circuit may include: multiple Signal interface modules 10, for example, the letter Number Acquisition Circuit may include four Signal interface modules 10, still, since any moment analog-to-digital conversion module 20 is only capable of acquisition 1 Therefore road signal please refers to Figure 13, which can also include: channel switching module 70 and channel control module 80, signal all the way is selected in the multiple signals that multiple Signal interface modules 10 acquire according to detection demand and by the selection Signal output.

Please refer to Figure 13, channel switching module 70 respectively with channel control module 80, each Signal interface module 10 and First voltage follows module 50 to couple, which is used under the control signal from channel control module 80, The signal from echo signal interface module is inputted to the output end of channel switching module 70, and passes through the channel switching module 70 Output end to first voltage follow module 50 export the signal from echo signal interface module, wherein the echo signal Interface module is that module indicated by signal is controlled in multiple Signal interface modules 10.

Optionally, channel control module 80 may include: the multiple switch submodule being arranged successively, each switch submodule Exportable switching signal, the control signal from channel control module 80 include the switch letter of multiple switch submodule output Number.Illustratively, which includes: toggle switch.

When signal acquisition circuit includes four Signal interface modules 10, the structural schematic diagram of channel switching module 70 please join Figure 14 is examined, which may include: channel conversion chip.Optionally, it is imitated to reach preferable common mode inhibition Fruit, the conduction resistance value of the channel conversion chip can be 40 ohm, using the power supply of 12V single supply, the channel The input voltage range of conversion chip can reach 22 volts, to realize preferable common mode inhibition effect.

Please continue to refer to Figure 14, which includes enable signal input pin EN, control signal input tube foot A0 to A2, acquisition signal input tube foot S1 to S8, the first power pin VDD, second source pin VSS, ground pin GND and defeated Pin D out.Wherein, from enable signal input pin EN input enable signal for control channel conversion chip start to work or It stops working.Control signal input tube foot A0 to A2 is used to receive the control inputted by control signal end A0_IN, A1_IN and A2_IN Signal processed, in order to which channel conversion chip determines echo signal interface according to the control signal in four Signal interface modules 10 Module.Acquisition signal input tube foot S1 to S4 is respectively used to input one and routes the signal that corresponding Signal interface module 10 inputs, and Each input pin passes through capacitor and voltage-stabiliser tube ground connection in parallel.First power pin VDD is connect with second source end VGH2, And first power pin VDD also passes through capacitor C61 and is grounded, second source pin VSS and ground pin GND are grounded, output Pin D is for exporting the signal from echo signal interface module.

Optionally, the structural schematic diagram of channel control module 80 please refers to Figure 15, which includes: successively Four switch submodules of arrangement, each switch submodule includes: toggle switch SW, the output end S0_ of first switch submodule EN is connect with the enable signal input pin EN of channel switching chip, and output terminals A 0_IN and the channel of second switch submodule are cut The control signal input tube foot A0 connection of chip is changed, third switchs the control of the output terminals A 1_IN and channel switching chip of submodule Signal input tube foot A1 connection processed, the output terminals A 2_IN of the 4th switch submodule and the control signal of channel switching chip input Pin A2 connection, the output end of each switch submodule passes through pull-up resistor and connect with third power end VGH3, and the pull-up One end that resistance is connect with power end also passes through filter capacitor C62 and is grounded.The output end of each switch submodule also passes through one Toggle switch SW ground connection, when toggle switch is in different conditions, the potential value of the signal of output end output is different, such as: For first toggle switch in Figure 15, when the toggle switch is allocated at 1, output end output is in the switch of high potential Signal, when the toggle switch is allocated at 8, output end output is in the switching signal of low potential；For in Figure 15 second A toggle switch, when the toggle switch is allocated at 2, output end output is in the switching signal of high potential, when the dial-up When switch is allocated at 7, output end output is in the switching signal of low potential；For third toggle switch in Figure 15, when When the toggle switch is allocated at 3, output end output is in the switching signal of high potential, when the toggle switch is allocated at 6 When, output end output is in the switching signal of low potential；For the 4th toggle switch in Figure 15, when the toggle switch is dialled When to 4, output end output is in the switching signal of high potential, when the toggle switch is allocated at 5, output end output Switching signal in low potential.

From the foregoing, it will be observed that can be realized using signal acquisition circuit provided by the utility model to analog quantity current signal, mould The acquisition of analog quantity voltage signal and on-off model effectively improves the benefit of signal acquisition circuit compared to the relevant technologies With rate.Also, by signal acquisition circuit provided by the utility model at least may be implemented the analog quantity electric current to 4-20 milliamperes, The analog quantity voltage of 0-5V and the detection of switching value increase the detection range of circuit compared to the relevant technologies, and expand The scope of application of circuit.Further, since the various pieces of the signal acquisition circuit are modularization setting, so that each mould Block can be compatible with the detection device that finished product on the market is sold, and improves the scope of application of the signal acquisition circuit.

It should be noted that the parameter of components and each power supply such as each resistance and capacitor in the signal acquisition circuit Holding the amplitude of the power supply signal provided can be configured according to actual needs, and the utility model embodiment is to its insufficient specific limit It is fixed.

In conclusion signal acquisition circuit provided by the utility model, which includes: signaling interface mould Block, the Signal interface module are configured at least three input terminals, are configured by the connection type to three input terminals, can Realize the acquisition to different types of signal, relative to the relevant technologies, which can either realize that switch amount is believed Number acquisition, additionally it is possible to realize acquisition to analog quantity current signal and analog quantity voltage signal, effectively improve signal and adopt The utilization rate of collector.

The utility model embodiment additionally provides a kind of storage medium, and computer program is stored in the storage medium, meter Calculation machine program realizes the driving method of signal acquisition circuit provided by the embodiment of the utility model when being executed by processor.

The above is only the preferred embodiment of the present invention, is not intended to limit the utility model, all practical at this Within novel spirit and principle, any modification, equivalent replacement, improvement and so on should be included in the guarantor of the utility model Within the scope of shield.

Claims (13)

1. a kind of signal acquisition circuit, which is characterized in that the signal acquisition circuit includes: Signal interface module；

The Signal interface module is coupled with the first power end, the first output and ground respectively, and the signaling interface mould Block is configured at least three input terminals, and at least three input terminal includes: first input end, the second input terminal and third input End, the first input end are coupled with first power end, and second input terminal is coupled with first output end, described Third input terminal is coupled with the ground terminal；

Second input terminal is used for when the first input end and second input terminal are shorted, loaded switches amount letter to be measured Number；

Second input terminal is used for when the third input terminal and second input terminal are shorted, and loading simulation amount electric current waits for Survey signal；

Second input terminal is used for short not with second input terminal in the first input end and the third input terminal When connecing, loading simulation amount voltage measured signal.

2. signal acquisition circuit according to claim 1, which is characterized in that the signal acquisition circuit further include: modulus Conversion module；

The analog-to-digital conversion module is coupled with first output end and processing component respectively, and the analog-to-digital conversion module is used for will Digital signal is converted to by the signal that first output end inputs, and inputs the digital signal, institute to the processing component Processing component is stated for detecting according to the digital signal to the measured signal.

3. signal acquisition circuit according to claim 2, which is characterized in that the signal acquisition circuit further include: voltage Conversion module；

The voltage transformation module is coupled with first output end and the analog-to-digital conversion module respectively, the voltage modulus of conversion Block is used to zoom in and out the amplitude of the signal inputted processing by first output end, and inputs to the analog-to-digital conversion module Scaled treated signal.

4. signal acquisition circuit according to claim 3, which is characterized in that the voltage transformation module includes: that voltage turns Change chip；

The voltage conversion chip includes: the first reference signal input pin, the second reference signal input pin, reference voltage letter Number input pin and second output terminal, the first reference signal input pin is used to receiving to be inputted by first output end Signal, the voltage conversion chip are used to come from second reference signal according to the signal inputted by first output end Second reference signal of input pin, and, the reference voltage signal from the reference voltage signal input pin, to by institute The signal for stating the input of the first output end zooms in and out processing, and described scaled treated believes to second output terminal input Number.

5. signal acquisition circuit according to claim 3, which is characterized in that the voltage transformation module includes: that operation is put Big device.

6. according to any signal acquisition circuit of claim 3 to 5, which is characterized in that the voltage transformation module also with Power module coupling, the power module are used for the voltage transformation module input reference voltage signal.

7. signal acquisition circuit according to claim 6, which is characterized in that the power module includes: power supply conversion Module and voltage follow submodule；

The power convert submodule is coupled with first power end and the voltage follow submodule respectively, and the power supply turns Submodule is changed for the voltage signal from first power end to be converted to the voltage signal of default amplitude；

The voltage follow submodule is also coupled with the voltage transformation module, and the voltage follow submodule is used for the electricity Voltage signal after pressing the input conversion of conversion module full width.

8. according to any signal acquisition circuit of claim 3 to 5, which is characterized in that the signal acquisition circuit also wraps Include: first voltage follows module；

The first voltage follows module to couple respectively with first output end and the voltage transformation module, first electricity Pressure follows module for inputting the input signal inputted by first output end to the voltage transformation module full width.

9. signal acquisition circuit according to claim 8, which is characterized in that the signal acquisition circuit further include: second Voltage follow module；

The second voltage follows module to couple respectively with the voltage transformation module and the ground terminal, the second voltage with It is used to input the ground signalling from the ground terminal to the voltage transformation module full width with module.

10. signal acquisition circuit according to any one of claims 1 to 5, which is characterized in that the signal acquisition circuit packet It includes: multiple Signal interface modules, the signal acquisition circuit further include: channel switching module and channel control module；

The channel switching module is coupled with the channel control module and each Signal interface module respectively, the channel switching Module is used under the control signal from the channel control module, is come to the input of the output end of the channel switching module The signal of echo signal interface module, the echo signal interface module are that letter is controlled described in the multiple Signal interface module Module indicated by number.

11. signal acquisition circuit according to claim 10, which is characterized in that the channel control module includes: successively The multiple switch submodule of arrangement, the control signal include the output signal of the multiple switch submodule.

12. signal acquisition circuit according to claim 11, which is characterized in that the switch submodule includes: that dial-up is opened It closes.

13. signal acquisition circuit according to any one of claims 1 to 5, which is characterized in that

Pull-up resistor is in series between the first input end of the Signal interface module and first power end；

Pull down resistor is in series between the third input terminal and the ground terminal of the Signal interface module.