CN106354187B - Sensing circuit and control method thereof - Google Patents
Sensing circuit and control method thereof Download PDFInfo
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- CN106354187B CN106354187B CN201610800650.3A CN201610800650A CN106354187B CN 106354187 B CN106354187 B CN 106354187B CN 201610800650 A CN201610800650 A CN 201610800650A CN 106354187 B CN106354187 B CN 106354187B
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- 238000000034 method Methods 0.000 title claims description 19
- 230000008878 coupling Effects 0.000 claims description 13
- 238000010168 coupling process Methods 0.000 claims description 13
- 238000005859 coupling reaction Methods 0.000 claims description 13
- 230000005611 electricity Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 9
- 239000013078 crystal Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 241000208340 Araliaceae Species 0.000 description 4
- 235000005035 Panax pseudoginseng ssp. pseudoginseng Nutrition 0.000 description 4
- 235000003140 Panax quinquefolius Nutrition 0.000 description 4
- 230000005669 field effect Effects 0.000 description 4
- 235000008434 ginseng Nutrition 0.000 description 4
- 238000005259 measurement Methods 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- 239000002033 PVDF binder Substances 0.000 description 2
- KZNMRPQBBZBTSW-UHFFFAOYSA-N [Au]=O Chemical compound [Au]=O KZNMRPQBBZBTSW-UHFFFAOYSA-N 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 238000013507 mapping Methods 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000001151 other effect Effects 0.000 description 1
- 230000035479 physiological effects, processes and functions Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
- G05F1/00—Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
- G05F1/10—Regulating voltage or current
- G05F1/46—Regulating voltage or current wherein the variable actually regulated by the final control device is dc
- G05F1/56—Regulating voltage or current wherein the variable actually regulated by the final control device is dc using semiconductor devices in series with the load as final control devices
- G05F1/561—Voltage to current converters
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Abstract
The invention discloses a sensing circuit, which comprises a sensing module and a reading module. The sensing module is used for receiving the sensing voltage and correspondingly outputting the output current. The sensing module comprises a sensing transistor and a current mirror unit. The first terminal of the sensing transistor is used for receiving a reference voltage. The sensing transistor is used for outputting a reference current according to a reference voltage and a sensing voltage. The current mirror unit is electrically coupled to the sensing transistor and is used for outputting an output current according to the reference current map. The reading module and the sensing module are electrically coupled to a node and output an output voltage signal according to the output current. The voltage level of the node is substantially the same as the reference voltage.
Description
Technical field
Present invention is on a kind of sensing circuit, and especially with regard to a kind of circuit structure using sensing circuit and control
Method processed.
Background technology
Recently, pulses measure or other physiology letter are widely used in as the piezoelectric membrane sensor made by piezoelectric
Number measurement etc. is among the related application of pressure measxurement.
However, the voltage and curent change that piezoelectric can be generated at present are very faint, therefore its output signal is easy
Disturbed by the noise in environment or back-end circuit so that the easy distortion of measurement result.
The content of the invention
One aspect of present invention is sensing circuit.Sensing circuit includes sensing module and read module.Sense mould
Block is receiving sensing voltage and correspondingly export output current.Sensing module includes sensing transistor and current lens unit.
The first end of sensing transistor is receiving reference voltage.Sensing transistor is to according to reference voltage and sensing voltage output ginseng
Examine electric current.Current lens unit electric property coupling sensing transistor, to map output output current according to reference current.Read module
A node is electrically coupled to sensing module, and an output voltage signal is exported according to output current.The voltage level of node with
Reference voltage is roughly the same.
Another aspect of present invention is sensing circuit.Pressure sensing circuit includes sensing element, sensing transistor, the
One transistor, second transistor and read module.Sensing element is to according to sensing result output sensing voltage.Sense crystal
Pipe is included to receive the first end of the first reference voltage, the second end, and is electrically coupled to sensing element, to self-inductance measurement member
Part receives the control terminal of sensing voltage.The first transistor include be electrically coupled to the end of sensing transistor second first end, to
The second end of the second reference voltage is received, and is electrically coupled to the control terminal of the first transistor first end.Second transistor bag
Containing first end, receiving the second end of the second reference voltage, and be electrically coupled to the control terminal of the first transistor control terminal.
Read module includes input and output end.The voltage level of the input of read module and the first reference voltage substantially phase
Together.The output end of read module is to according to the sensing output voltage signal of voltage output one.
The another aspect of present invention is the control method of sensing circuit.Control method includes is joined by offer sensing module
Examine voltage；Output current is correspondingly exported in the output end of sensing module according to sensing voltage；Controlled and sensed by read module
The voltage level of the output end of module, make the voltage level of the output end of sensing module roughly the same with reference voltage；And root
One output voltage signal is exported by the read module according to output current.
Brief description of the drawings
Fig. 1 is the schematic diagram of the sensing circuit according to depicted in present invention section Example.
Fig. 2 is the voltage oscillogram according to depicted in present invention section Example.
Fig. 3 is the schematic diagram of the sensing circuit according to depicted in present invention other parts embodiment.
Fig. 4 is the schematic diagram of the sensing circuit according to depicted in present invention other parts embodiment.
Fig. 5 is the schematic diagram of the sensing circuit according to depicted in present invention other parts embodiment.
Fig. 6 is the schematic diagram of the sensing circuit according to depicted in present invention other parts embodiment.
Fig. 7 is the schematic diagram of the sensing circuit according to depicted in present invention other parts embodiment.
Fig. 8 is the flow chart of the control method of the sensing circuit according to depicted in present invention section Example.
Wherein, reference：
100 sensing circuits
110 sensing elements
120 sensing modules
122 current lens units
140 read modules
300th, 400,500,600,700 sensing circuit
322nd, 522,622,722 current lens unit
800 control methods
S810~S840 steps
Q1 sensing transistors
Q2, Q3, Q4 transistor
OP1 operational amplifiers
S1 is switched
C1 electric capacity
R1, R2, R3 resistance
N1, N2 node
VDD, VSS reference voltage
Vp senses voltage
Vo output voltage signals
I1 reference currents
I2 output currents
CLK clock signals
Embodiment
Hereafter institute's accompanying drawings are coordinated to elaborate for embodiment, to more fully understand the aspect of present invention, but institute
The embodiment of offer is simultaneously not used to the scope that the limitation present invention is covered, and the description of structure operation is not used to limit its execution
Sequentially, any structure reconfigured by element, it is produced that there is equal and other effects device, it is all the model that the present invention is covered
Enclose.In addition, according to the standard and practice of industry, schema is mapped only for the purpose of aid illustration not according to full size, real
The size of various features can be increased or decreased arbitrarily in order to illustrate on border.Similar elements will be accorded with identical in the description below
Number sign illustrates in order to understand.
In word (terms) used in full piece specification and claim, in addition to having and especially indicating, generally have
Each word using in the content invented in this area, at this with the usual meaning in special content.It is some describing this
The word of invention by it is lower or this specification other places discuss, to provide those skilled in the art in description for the present invention
Upper extra guiding.
In addition, word "comprising", " comprising ", " having ", " containing " etc. used in herein, are open
Term, that is, mean " including but not limited to ".In addition, used herein " and/or ", comprising one or more in associated listed items
Any one and its all combination of individual project.
In this article, when an element is referred to as " connecting " or when " coupling ", can refer to " electric connection " or " electric property coupling ".
" connection " or " coupling " also can be used to represent to be collocated with each other operation or interactive between two or multiple element.Although in addition, make herein
With " first ", " second " ... wait term to describe different elements, the term be only distinguish with constructed term describe member
Part or operation.Indicated unless context understands, otherwise order or cis-position are not especially censured or implied to the term, is also not used to limit
The fixed present invention.
It refer to Fig. 1.Fig. 1 is the schematic diagram of the sensing circuit 100 according to depicted in present invention section Example.Such as
Shown in Fig. 1, in some embodiments, sensing circuit 100 includes sensing element 110, sensing module 120 and read module 140.
In structure, the output end of the input electric property coupling sensing element 110 of sensing module 120.The input electricity of read module 140
Property coupling sensing module 120 output end.By sensing module 120 and the cooperating of read module 140, sensing circuit 100
Output voltage signal Vo can be correspondingly provided according to the sensing voltage Vp that sensing element 110 exports.Specifically, implement in part
In example, sensing module 120 correspondingly produces output current I2 to receive sensing voltage Vp from input from output end.Read
Modulus block 140 exports above-mentioned output voltage signal Vo to from input Rreceive output electric current I2 from output end.
For example, in some embodiments, sensing element 110 can be by piezoelectric, such as piezoelectric polyvinylidene fluoride
(PVDF) high molecular polymer etc., made piezoelectric membrane sensor.Sensing element 110 is corresponding to pressure output sensing electricity
After pressing Vp, the exportable corresponding output voltage signal Vo of sensing circuit 100 is to judge pressure size.Thereby, sensing circuit 100 can
For detecting human pulse or other various biological characteristics.
As shown in figure 1, in some embodiments, sensing module 120 can include sensing transistor Q1 and current lens unit
122.In structure, to receive reference voltage VDD, sensing transistor Q1 the second end is electrical for sensing transistor Q1 first end
The reference arm of current lens unit 122 is coupled to, sensing transistor Q1 control terminal senses voltage Vp to receive.Consequently, it is possible to
Sensing transistor Q1 can export reference current I1 to the ginseng of current lens unit 122 according to reference voltage VDD and sensing voltage Vp
Examine arm.
In some embodiments, current lens unit 122 includes transistor Q2, Q3.For example, transistor Q2, Q3 can be N
Type metal oxide semiconductor field-effect transistor (N-type Metal-Oxide-Semiconductor Field-Effect
Transistor, nMOSFET, nMOS).In structure.Transistor Q2 first end is electrically coupled to the of sensing transistor Q1
Two ends, transistor Q2 the second end are electrically coupled to earth terminal, to receive reference voltage VSS, transistor Q3 first end electricity
Property is coupled to the output end of sensing module (i.e.：Node N1), transistor Q3 the second end is electrically coupled to earth terminal, to receive
Reference voltage VSS.Transistor Q2, Q3 control terminal electric property coupling, and be electrically coupled to transistor Q2 first end each other, with shape
Into current mirroring circuit.As illustrated, in some embodiments, due to transistor Q2 first end and control terminal electrical coupling each other
Connect, transistor Q2 gate-source voltage is transistor Q2 pressure difference of the first end with reference voltage VSS.When sensing voltage Vp is carried
Gao Shi, as the voltage level at sensing transistor Q1 the second end improves, transistor Q2 gate-source voltage is also improved, made therewith
Reference current I1 is obtained to improve therewith.Consequently, it is possible to when reference current I1 flows through the transistor on the reference arm of current lens unit 122
During Q2, in will there is the output current I2 corresponding to reference current I1 to produce on the output arm of current lens unit 122 and flow through crystalline substance
Body pipe Q3.Proportionate relationship between output current I2 and reference current I1 can be carried out by the transistor unit from suitable parameter
Design, its concrete principle repeat no more in this.
Thereby, by the operation of sensing transistor Q1 and current lens unit 122, sensing module 120 can be by sensing element
The sensing voltage Vp of 110 outputs is converted to appropriate current signal (i.e.：Output current I2) to read module 140.For example,
In some embodiments, output current I2 caused by current lens unit 122 can amplify reference current I1 current value to scale.
Even if the consequently, it is possible to sensing voltage Vp caused references corresponding to the reference side of current lens unit 122 that sensing element 110 is exported
Electric current I1 only has minor variations, output current I2 caused by the mapping of the outlet side of current lens unit 122 and according to output current I2
Caused output voltage signal Vo can still represent detected pressure size, avoid the ambient noise and back-end circuit on circuit
Interference causes process circuit to be judged by accident.Thereby, sensing circuit 100 can lift the sensitivity and the degree of accuracy of sensing.
As shown in figure 1, in some embodiments, read module 140 include operational amplifier OP1, resistance R1, electric capacity C1 with
And switch S1.In structure, operational amplifier OP1 includes first input end (such as：Negative pole end), the second input (such as：Positive pole
End) and output end, wherein first input end be electrically coupled to the input of read module 140 (i.e.：Node N1), the second input
End is to receive reference voltage VDD, and output end is exporting an output voltage signal Vo.Resistance R1, electric capacity C1 and switch S1
It is electrically coupled between operational amplifier OP1 the first output end and output end.In other words, resistance R1, electric capacity C1 and switch
S1 is each other with parallel form electric property coupling, formation operational amplifier OP1 feedback circuit.Assuming that operational amplifier OP1 input
Impedance is sufficiently large, then operational amplifier OP1 first input end and the second input are imaginary short (Virtual Short), greatly
Cause has same voltage level.Consequently, it is possible to because operational amplifier OP1 the second input receives reference voltage VDD, therefore
Node N1 voltage level is just roughly the same with reference voltage VDD.
In some embodiments, S1 is switched to receive clock signal CLK, and is optionally led according to clock signal CLK
It is logical.When switching S1 conductings, the feedback impedance of amplifier circuit is zero, and read module 140 can be considered voltage follower so that defeated
Going out voltage signal Vo has the voltage level substantially the same with reference voltage VDD.
Relatively, when switching S1 cut-offs, the feedback circuit of amplifier circuit is the resistance R1 and electric capacity C1 being connected in parallel to each other.
Because the output current I2 that sensing module 120 exports flows through resistance R1, therefore output voltage signal Vo voltage level is (VDD+
I2·R1).Because output current I2 size of current is corresponding to sensing voltage Vp, therefore output voltage signal Vo is also corresponding to sense
Voltage Vp is surveyed, consequently, it is possible to which the process circuit of rear end can judge that sensing element 110 is sensed according to output voltage signal Vo
Pressure size.In some embodiments, electric capacity C1 can filter out the exchange vibration in output voltage signal Vo as filter element
Composition, to avoid back-end circuit from judging signal by accident.
Please also refer to Fig. 2.Fig. 2 is the voltage oscillogram according to depicted in present invention section Example.For convenience
And for the sake of clear explanation, depicted voltage waveform coordinates the sensing circuit 100 in embodiment illustrated in fig. 1 to illustrate in Fig. 2,
But and it is not used to limit present invention.
As shown in Fig. 2 in some embodiments, after sensing element 110 senses pressure, its sensing voltage Vp exported
There is specific voltage swing and waveform corresponding to pressure size.When clock signal CLK is in high level, switch S1 is led
It is logical, output voltage signal Vo be a low level definite value (such as：Reference voltage VDD).Relatively, when clock signal CLK is in low
During level, switch S1 cut-offs, output voltage signal Vo will have the voltage swing and waveform corresponding to sensing voltage Vp.(such as：
VDD+I2·R1).Consequently, it is possible to read module 140 can carry out sample of signal according to clock signal CLK, it is above-mentioned defeated to export
Go out voltage signal Vo.
Consequently, it is possible to during sensing circuit 100 provides output voltage signal Vo according to sensing voltage Vp, as reading
The voltage level of the input of modulus block 140 and the node N1 of the output end of sensing module 120 substantially maintains reference voltage
VDD.Thereby, the reference current I1 of the reference side of current lens unit 122 can map to the output current I2 of outlet side exactly.
Specifically, when voltage mismatches between transistor Q2, Q3 drain-source, the passage length modulation effect of transistor
(Channel length modulation effect), can cause reference current I1 and output current I2 proportionate relationship to have
Error.Output current I2 and reference current I1 relational expression can be expressed from the next：
Wherein WQ2、WQ3Transistor Q2, Q3 grid width, L are represented respectivelyQ2、LQ3Transistor Q2, Q3 grid are represented respectively
Pole length, VDSQ2、VDSQ3Voltage between transistor Q2, Q3 drain-source is represented respectively, and λ represents passage length modulation effect coefficient.
Sensing circuit 100 is by control node N1 voltage level, and voltage is (i.e. between can control transistor Q3 drain-source：
VDSQ3), and reduce because of voltage non-matching phenomenon between transistor Q2, Q3 drain-source caused by the floating of node N1 voltages.Such one
Come, output current I2 and output voltage signal Vo error also decreases so that the overall sensing precision of sensing circuit 100
Lifting.
Depicted sensing module 120 is only that signal is used in Fig. 1, and is not used to limit this case.In present invention
In each embodiment, sensing module 120 can be by different circuit realirations, and the paragraphs below corresponding schema that will arrange in pairs or groups illustrates.
It refer to Fig. 3.Fig. 3 is the signal of the sensing circuit 300 according to depicted in present invention other parts embodiment
Figure.In Fig. 3, the similar components relevant with Fig. 1 embodiment represent in order to understand with the same references, and similar finite element
The concrete principle of part describes in detail in previous paragraph, if not there is Collaboration relation with Fig. 3 interelement and necessary be situated between
The person of continuing, repeated no more in this.In the embodiment depicted in Fig. 3, compared with the sensing circuit 100 depicted in Fig. 1, current mirror list
Transistor Q2, Q3 in member 322 can be P-type mos field-effect transistor (P-type Metal-Oxide-
Semiconductor Field-Effect Transistor, pMOSFET, pMOS).
In addition, in the embodiment shown in fig. 3, sensing transistor Q1 first end is electrically coupled to earth terminal, to receive
Reference voltage VSS, sensing transistor Q1 the second end are electrically coupled to the reference arm of current lens unit 322, sensing transistor Q1
Control terminal to receive sensing voltage Vp, to export reference current I1 to electric current according to reference voltage VSS and sensing voltage Vp
The reference arm of mirror unit 322.
In structure, transistor Q2 first end is electrically coupled to sensing transistor Q1 the second end, and the of transistor Q2
To receive reference voltage VDD, transistor Q3 first end is electrically coupled to the output end of sensing module 120 (i.e. at two ends：Node
N1), transistor Q3 the second end is receiving reference voltage VDD.Transistor Q2, Q3 control terminal electric property coupling, and electricity each other
Property is coupled to transistor Q2 first end, to form current mirroring circuit.
Consequently, it is possible to it is similar to current lens unit 122 depicted in Fig. 1, when reference current I1 flows through current lens unit
During transistor Q2 on 322 reference arm, in will have corresponding to the defeated of reference current I1 on the output arm of current lens unit 322
Go out electric current I2 to produce and flow through transistor Q3.
It refer to Fig. 4.Fig. 4 is the signal of the sensing circuit 400 according to depicted in present invention other parts embodiment
Figure.In Fig. 4, the similar components relevant with Fig. 1 embodiment represent in order to understand with the same references, and similar finite element
The concrete principle of part describes in detail in previous paragraph, if not there is Collaboration relation with Fig. 4 interelement and necessary be situated between
The person of continuing, repeated no more in this.In the embodiment depicted in Fig. 4, compared with the sensing circuit 100 depicted in Fig. 1, read module
140 further include resistance R2, the R3 to contact each other.In structure, resistance R2 first end to receiving voltage Vin, resistance R2's
Second end is electrically coupled to operational amplifier OP1 the second input (such as：Electrode input end) and resistance R3 first end.Electricity
Resistance R3 the second end is electrically coupled to earth terminal.
Consequently, it is possible to by resistance R2, R3 partial pressure, operational amplifier OP1 the second input is (such as：Electrode input end)
Just it is operable in appropriate voltage level so that the second input is (such as：Electrode input end) voltage level and reference voltage VDD
It is roughly the same.For example, in some embodiments, the voltage level of operational amplifier OP1 the second input is Vin.
[(R3)/(R2+R3)].In other words, by adjusting resistance R2, R3 resistance, the second of operational amplifier OP1 can be controlled to input
The voltage level at end is roughly the same with reference voltage VDD, and then causes the node N1 of imaginary short voltage level and reference voltage
VDD is roughly the same.
It refer to Fig. 5.Fig. 5 is the signal of the sensing circuit 500 according to depicted in present invention other parts embodiment
Figure.In Fig. 5, the similar components relevant with Fig. 1 embodiment represent in order to understand with the same references, and similar finite element
The concrete principle of part describes in detail in previous paragraph, if not there is Collaboration relation with Fig. 5 interelement and necessary be situated between
The person of continuing, repeated no more in this.In the embodiment depicted in Fig. 5, compared with the sensing circuit 100 depicted in Fig. 1, current mirror list
Member 522 includes transistor Q2, Q3, Q4.In some embodiments, transistor Q2, Q3, Q4 can be nMOS.
In structure, transistor Q2 first end is electrically coupled to sensing transistor Q1 the second end, and the of transistor Q2
Two ends are receiving reference voltage VSS.Transistor Q3 first end is electrically coupled to transistor Q4 the second end, transistor Q3's
Second end is electrically coupled to transistor Q2 the second end, to receive reference voltage VDD.Transistor Q2, Q3 control terminal are each other
Electric property coupling, and it is electrically coupled to transistor Q2 first end.Transistor Q4 first end is electrically coupled to sensing module 120
Output end is (i.e.：Node N2), transistor Q4 control terminal is electrically coupled to sensing transistor Q1 control terminal, to receive sensing
Voltage Vp, to form current mirroring circuit.
Consequently, it is possible to it is similar to current lens unit 122 depicted in Fig. 1, when reference current I1 flows through current lens unit
During transistor Q2 on 522 reference arm, in will have corresponding to the defeated of reference current I1 on the output arm of current lens unit 522
Go out electric current I2 to produce and flow through transistor Q3, Q4.
It is similar to previous embodiment, because operational amplifier OP1 electrode input end and negative input are imaginary short
(Virtual Short), therefore node N2 voltage level is just roughly the same with reference voltage VDD.Consequently, it is possible to sensing module
Sensing transistor Q1 and transistor Q4 in 120 is mutually symmetrical, and transistor Q2 is mutually symmetrical with transistor Q3, can further drop
The reference arm of low current mirror unit 522 on output arm by the electric current caused by passage length modulation effect with, because voltage mismatches, being missed
Difference.In other words, by setting transistor Q4 corresponding with sensing transistor Q1, reference current I1 and output electricity can further be reduced
Flow the error between I2.
Specifically, compared with embodiment illustrated in fig. 1, node N1 voltage level and reference voltage VDD be substantially in Fig. 1
It is identical.However, sensing transistor Q1 in itself caused by pressure drop so that actually between transistor Q2 drain-source voltage with it is brilliant
Voltage and non-fully matched between body pipe Q3 drain-source.Consequently, it is possible to due to the passage length modulation effect of transistor, can cause to join
The proportionate relationship for examining electric current I1 and output current I2 still has error.Relatively, in Figure 5, node N2 voltage level and ginseng
It is roughly the same to examine voltage VDD.Due to being provided with transistor Q4 corresponding with sensing transistor Q1 in current mirroring circuit 522, therefore
Pressure drop on reference arm caused by sensing transistor Q1 is identical with the pressure drop caused by transistor Q4 on output arm.Consequently, it is possible to
Voltage is just roughly the same between voltage and transistor Q3 drain-source between transistor Q2 drain-source.Thereby, electricity on reference arm and output arm
Press unmatched phenomenon to be improved, and then reduce reference current I1 and output current I2 error.
Thereby, the output voltage signal Vo that read module 140 is exported according to output current I2 just can be more accurate, to carry
Rise the degree of accuracy that sensing circuit 100 senses pressure.
Although in addition, in the embodiment depicted in Fig. 5, sensing transistor Q1 and transistor Q2~Q4 is all isomrophous crystal
Pipe is (such as：N-type MOS transistor), but present invention is not limited thereto.It refer to Fig. 6.Fig. 6 is according to present invention
The schematic diagram of sensing circuit 600 depicted in other parts embodiment.In Fig. 6, the similar components relevant with Fig. 5 embodiment
Represent with the same references in order to understand, and the concrete principle of similar components describes in detail in previous paragraph, if
It is non-to there is Collaboration relation and necessity person of introduction with Fig. 5 interelement, repeated no more in this.In the embodiment depicted in Fig. 6
In, compared with the sensing circuit 500 depicted in Fig. 5, transistor Q2, Q3 in current lens unit 622 are n-type gold oxygen semi-crystal
Manage, the transistor Q4 and sensing transistor Q1 in current lens unit 622 are p-type MOS transistor.In other words, it is real in part
Apply in example, transistor Q2, Q3 can be the first transistor npn npn, and transistor Q4 and sensing transistor Q1 can be to be different from the first type crystal
Second transistor npn npn of pipe.
In addition, in some embodiments, sensing transistor Q1 and transistor Q2~Q4 also can be all p-type gold oxygen semi-crystal
Pipe.It refer to Fig. 7.Fig. 7 is the schematic diagram of the sensing circuit 700 according to depicted in present invention other parts embodiment.In
In Fig. 7, the similar components relevant with Fig. 5 embodiment represent in order to understand with the same references, and similar components
Concrete principle describes in detail in previous paragraph, necessity person of introduction if not having Collaboration relation with Fig. 5 interelement,
Repeated no more in this.
In the embodiment depicted in Fig. 7, compared with the sensing circuit 500 depicted in Fig. 5, sensing transistor Q1 and electricity
Transistor Q2, Q3, the Q4 flowed in mirror unit 722 is p-type MOS transistor.
It is similar with embodiment depicted in Fig. 3, because operational amplifier OP1 electrode input end and negative input are
The characteristic of imaginary short, node N2 voltage level are roughly the same with reference voltage VSS.Consequently, it is possible to the sense in sensing module 120
Survey transistor Q1 and transistor Q4 to be mutually symmetrical, transistor Q2 is mutually symmetrical with transistor Q3, can further reduce with reference to electricity
Flow I1 and output current I2 between error, its concrete principle is similar to previous embodiment, and in previous paragraph specifically
It is bright, therefore repeated no more in this.
It refer to Fig. 8.Fig. 8 is the control method 800 of the sensing circuit according to depicted in present invention section Example
Flow chart.For convenience and for the sake of clear explanation, following control methods 800 are to coordinate sense depicted in Fig. 1~Fig. 7 embodiments
Slowdown monitoring circuit 100,300~700 illustrates, but is not limited, any to be familiar with this those skilled in the art, is not departing from present invention
In spirit and scope, when can to make it is various change and retouching.As shown in figure 8, control method 800 include step S810, S820,
S830 and S840.
First, in step S810, reference voltage is received (such as by sensing module 120：Reference voltage VDD).
Then, in step S820, output electricity is correspondingly exported in the output end of sensing module 120 according to sensing voltage Vp
Flow I2.Specifically, in some embodiments, the step of exporting output current I2 can be included by sensing transistor Q1 according to reference
Voltage is (such as：Reference voltage VDD) and sensing voltage Vp output reference current I1, and by current lens unit (such as：Current lens unit
122) output output current I2 is mapped according to reference current I1.
Then, in step S830, the voltage level and ginseng of the output end of sensing module 120 are controlled by read module 140
Examine voltage (such as：Reference voltage VDD or reference voltage VSS) it is roughly the same.Specifically, in some embodiments, control sensing
The voltage level of the output end of module 120 include by operational amplifier OP1 first input end (such as：Negative input) Perceived control
Survey module 120 output end voltage level, and by operational amplifier OP1 the second input (such as：Electrode input end) connect
Receive reference voltage (such as：Reference voltage VDD).
Finally, in step S840, an output voltage signal Vo is exported according to output current I2 by read module 140.Tool
For body, in some embodiments, the step of exporting above-mentioned output voltage signal Vo, is further included by switching S1 according to clock signal
CLK selectively turns on operational amplifier OP1 first input end and operational amplifier OP1 output end.When switch S1 shut-offs
When, by operational amplifier OP1 output end output corresponding to the output voltage signal Vo for sensing voltage Vp.When switch S1 conductings
When, there is low level (such as by operational amplifier OP1 output end output：Reference voltage VDD) output voltage signal Vo.
Consequently, it is possible to read module 140 can carry out sample of signal and output voltage signal Vo according to clock signal CLK,
The process circuit of rear end can judge the pressure size that sensing element 110 is sensed according to output voltage signal Vo.
It is worth noting that, although disclosed method is shown and described as into a series of step or event herein,
It is it should be appreciated that these shown steps or the order of event should not be construed as limited significance.For example, part steps can be with
Different order occur and/or it is same with other steps in addition to step or event illustrated herein and/or described or event
Shi Fasheng.In addition, when implementing one or more aspects described herein or embodiment, and it is not all in this shows the step of all
To be required.In addition, one or more steps herein may also be held in one or more the step of separating and/or in the stage
OK.
Art tool usually intellectual can be directly acquainted with how this control method 800 is based on above-mentioned multiple differences
Sensing circuit 100,300~700 in embodiment is to perform such operation and function, therefore no longer this is repeated.
In summary, in each embodiment of present invention, sensing circuit by the imaginary short characteristic of operational amplifier,
By the voltage level control of node at sensing module and read module electric property coupling with sensing transistor identical reference voltage,
It may be such that there is symmetrical passage length modulation to imitate for the sensing transistor in sensing module and the transistor in current lens unit
Should, to reduce caused signal errors when reference current is mapped generation output current by current lens unit.Consequently, it is possible to read
The output voltage signal that module exports according to output current can have the higher degree of accuracy.
In addition, in some embodiments, current lens unit can include the transistor corresponding to sensing transistor so that sensing
Transistor in module is mutually symmetrical, and further reduces signal errors.
It is worth noting that, in the case where not conflicting, in each schema of present invention, embodiment and embodiment
Feature can be mutually combined with circuit.Depicted circuit is merely illustrative in schema is used, and simplifies so as to interest of clarity and be easy to
Understand, and be not used to limit present invention.
Although present invention is disclosed above with embodiment, so it is not limited to present invention, any ripe
This those skilled in the art is practised, in the spirit and scope for not departing from present invention, when various changes and retouching can be made, therefore in the present invention
The protection domain of appearance is worked as to be defined depending on appended claims institute defender.
Claims (13)
1. a kind of sensing circuit, it is characterised in that include：
One sensing module, to receive a sensing voltage and correspondingly export an output current, the sensing module includes：
One sensing transistor, a first end of the sensing transistor is to receive a reference voltage, and the sensing transistor is to root
According to the reference voltage and the reference current of sensing voltage output one；And
One current lens unit, the electric property coupling sensing transistor, the output current is exported to be mapped according to the reference current；With
And
One read module, the read module is electrically coupled to a node with the sensing module, and exports one according to the output current
The voltage level of output voltage signal, the wherein node is identical with the reference voltage.
2. sensing circuit according to claim 1, it is characterised in that the read module includes：
One operational amplifier, comprising：
One first input end, it is electrically coupled to the node；
One second input, to receive the reference voltage；And
One output end, to export the output voltage signal；And
One first resistor, it is electrically coupled between the first input end of the operational amplifier and the output end.
3. sensing circuit according to claim 2, it is characterised in that the read module further includes：
One first switch, it is electrically coupled between the first input end of the operational amplifier and the output end, the first switch
To be turned on according to a clock pulse signal-selectivity.
4. sensing circuit according to claim 3, it is characterised in that when the first switch turns on, output voltage letter
Number there is a low level, when the first switch turns off, the output voltage signal corresponds to the sensing voltage.
5. sensing circuit according to claim 1 a, it is characterised in that control terminal of the sensing transistor is receiving this
Voltage is sensed, the current lens unit includes：
One the first transistor, comprising：
One first end, it is electrically coupled to one second end of the sensing transistor；
One second end；And
One control terminal, it is electrically coupled to the first end of the first transistor；And
One second transistor, comprising：
One first end, it is electrically coupled to the node；
One second end, it is electrically coupled to second end of the first transistor；And
One control terminal, it is electrically coupled to the control terminal of the first transistor.
6. sensing circuit according to claim 1 a, it is characterised in that control terminal of the sensing transistor is receiving this
Voltage is sensed, the current lens unit includes：
One the first transistor, comprising：
One first end, it is electrically coupled to one second end of the sensing transistor；
One second end；And
One control terminal, it is electrically coupled to the first end of the first transistor；
One second transistor, comprising：
One first end；
One second end, it is electrically coupled to second end of the first transistor；And
One control terminal, it is electrically coupled to the control terminal of the first transistor；And
One third transistor, comprising：
One first end, it is electrically coupled to the node；
One second end, it is electrically coupled to the first end of the second transistor；And
One control terminal, it is electrically coupled to the control terminal of the sensing transistor.
7. a kind of sensing circuit, it is characterised in that include：
One sensing element, to according to the sensing voltage of sensing result output one；
One sensing transistor, comprising：
One first end, to receive one first reference voltage；
One second end；And
One control terminal, the sensing element is electrically coupled to, to receive the sensing voltage from the sensing element；
One the first transistor, comprising：
One first end, it is electrically coupled to second end of the sensing transistor；
One second end, to receive one second reference voltage；And
One control terminal, it is electrically coupled to the first end of the first transistor；
One second transistor, comprising：
One first end；
One second end, to receive second reference voltage；And
One control terminal, it is electrically coupled to the control terminal of the first transistor；And
One read module, comprising：
One input, the voltage level of the input are identical with first reference voltage；And
One output end, to according to the output voltage signal of sensing voltage output one.
8. sensing circuit according to claim 7, it is characterised in that the first end of the second transistor is electrically coupled to
The input of the read module, the read module include：
One operational amplifier, comprising：
One first input end, it is electrically coupled to the input of the read module；
One second input, to receive first reference voltage；And
One output end, to export the output voltage signal；
One first resistor, it is electrically coupled between the first input end of the operational amplifier and the output end；And
One first switch, it is electrically coupled between the first input end of the operational amplifier and the output end.
9. sensing circuit according to claim 7, it is characterised in that further include：
One third transistor, comprising：
One first end, it is electrically coupled to the input of the read module；
One second end, it is electrically coupled to the first end of the second transistor；And
One control terminal, it is electrically coupled to the control terminal of the sensing transistor.
10. a kind of control method of sensing circuit, it is characterised in that include：
The reference voltage of one sensing module one is provided；
One output current is correspondingly exported in an output end of the sensing module according to a sensing voltage；
The voltage level of the output end of the sensing module is controlled by a read module, makes the output end of the sensing module
Voltage level is identical with the reference voltage；And
One output voltage signal is exported by the read module according to the output current.
11. control method according to claim 10, it is characterised in that export the output current and include：
By a sensing transistor according to the reference voltage and the reference current of sensing voltage output one；And
Mapped by a current lens unit according to the reference current and export the output current.
12. control method according to claim 10, it is characterised in that control the voltage of the output end of the sensing module
Level includes：
The voltage level of the output end of the sensing module is controlled by a first input end of an operational amplifier；And
One second input for providing the operational amplifier receives the reference voltage.
13. control method according to claim 12, it is characterised in that export the output voltage signal and further include：
First input end and the fortune of the operational amplifier are turned on according to a clock pulse signal-selectivity by a first switch
Calculate an output end of amplifier；And
It is electric corresponding to the output of the sensing voltage by the output end output of the operational amplifier when the first switch turns off
Press signal.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW105120215A TWI638145B (en) | 2016-06-27 | 2016-06-27 | Sensing circuit and method for controlling sensing circuit |
| TW105120215 | 2016-06-27 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106354187A CN106354187A (en) | 2017-01-25 |
| CN106354187B true CN106354187B (en) | 2018-04-06 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201610800650.3A Expired - Fee Related CN106354187B (en) | 2016-06-27 | 2016-09-02 | Sensing circuit and control method thereof |
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| Country | Link |
|---|---|
| CN (1) | CN106354187B (en) |
| TW (1) | TWI638145B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI651929B (en) * | 2018-05-02 | 2019-02-21 | 友達光電股份有限公司 | Sense circuit |
| CN109965854B (en) * | 2018-08-29 | 2022-03-01 | 友达光电股份有限公司 | Sensing component and pulse condition measuring method |
| TWI689706B (en) * | 2018-12-21 | 2020-04-01 | 財團法人工業技術研究院 | Processing device for position sensing |
| US10742183B2 (en) | 2018-12-21 | 2020-08-11 | Industrial Technology Research Institute | Processing device for position sensing comprising a transforming differential current signal to a voltage signal performance |
| CN112904923B (en) * | 2019-12-03 | 2023-03-24 | 瑞昱半导体股份有限公司 | Current generating circuit |
| CN115379140A (en) * | 2021-05-20 | 2022-11-22 | 意法半导体股份有限公司 | Method of collecting sensing signals, corresponding sensor device and imaging camera |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5270660A (en) * | 1992-05-05 | 1993-12-14 | Xerox Corporation | Electrostatic voltmeter employing high voltage integrated circuit devices |
| US6108182A (en) * | 1998-10-30 | 2000-08-22 | Intersil Corporation | Overcurrent sensing circuit and self adjusting blanking |
| US7099204B1 (en) * | 2005-03-23 | 2006-08-29 | Spansion Llc | Current sensing circuit with a current-compensated drain voltage regulation |
| US8125456B2 (en) * | 2007-01-03 | 2012-02-28 | Apple Inc. | Multi-touch auto scanning |
| US8487639B1 (en) * | 2008-11-21 | 2013-07-16 | Cypress Semiconductor Corporation | Receive demodulator for capacitive sensing |
| US9444414B2 (en) * | 2014-07-11 | 2016-09-13 | Qualcomm Incorporated | Current sense circuit using a single opamp having DC offset auto-zeroing |
| US9746974B2 (en) * | 2014-08-21 | 2017-08-29 | Cypress Semiconductor Corporation | Providing a baseline capacitance for a capacitance sensing channel |
| KR20160050534A (en) * | 2014-10-30 | 2016-05-11 | 에스케이하이닉스 주식회사 | Semiconductor Integrated Circuit Device Having Unit for Sensing Leakage Current And Method of Operating The Same |
-
2016
- 2016-06-27 TW TW105120215A patent/TWI638145B/en not_active IP Right Cessation
- 2016-09-02 CN CN201610800650.3A patent/CN106354187B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| TWI638145B (en) | 2018-10-11 |
| TW201800722A (en) | 2018-01-01 |
| CN106354187A (en) | 2017-01-25 |
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