CN106354187A - Sensing circuit and control method thereof - Google Patents
Sensing circuit and control method thereof Download PDFInfo
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- CN106354187A CN106354187A CN201610800650.3A CN201610800650A CN106354187A CN 106354187 A CN106354187 A CN 106354187A CN 201610800650 A CN201610800650 A CN 201610800650A CN 106354187 A CN106354187 A CN 106354187A
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- 238000000034 method Methods 0.000 title claims description 19
- 230000008878 coupling Effects 0.000 claims description 12
- 238000010168 coupling process Methods 0.000 claims description 12
- 238000005859 coupling reaction Methods 0.000 claims description 12
- 230000001932 seasonal effect Effects 0.000 claims 2
- 230000005611 electricity Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 9
- 230000000694 effects Effects 0.000 description 7
- 241000208340 Araliaceae Species 0.000 description 5
- 235000005035 Panax pseudoginseng ssp. pseudoginseng Nutrition 0.000 description 5
- 235000003140 Panax quinquefolius Nutrition 0.000 description 5
- 239000013078 crystal Substances 0.000 description 5
- 235000008434 ginseng Nutrition 0.000 description 5
- 230000005669 field effect Effects 0.000 description 4
- 239000004065 semiconductor Substances 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- KZNMRPQBBZBTSW-UHFFFAOYSA-N [Au]=O Chemical compound [Au]=O KZNMRPQBBZBTSW-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 2
- 239000002033 PVDF binder Substances 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
- 230000006872 improvement Effects 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 238000013507 mapping Methods 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000035479 physiological effects, processes and functions Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
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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
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 with regard to a kind of sensing circuit, and especially with regard to a kind of circuit structure of employing sensing circuit and control
Method processed.
Background technology
Recently, the piezoelectric membrane sensor made by piezoelectric is widely used in pulses measure or other physiology letter
Number measurement etc. is in the middle of tonometric related application.
However, the voltage that current piezoelectric can be generated by is very faint with curent change, therefore its output signal is easy
Disturbed so that the easy distortion of measurement result by the noise in environment or back-end circuit.
Content of the invention
One aspect of present invention is sensing circuit.Sensing circuit comprises sensing module and read module.Sensing mould
Block is in order to receive sensing voltage and correspondingly to export output current.Sensing module comprises sensing transistor and current lens unit.
The first end of sensing transistor is in order to receive reference voltage.Sensing transistor is in order to according to reference voltage and sensing voltage output ginseng
Examine electric current.Current lens unit electric property coupling sensing transistor, in order to map output output current according to reference current.Read module
It is electrically coupled to a node with 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 comprise sensing element, sensing transistor,
One transistor, transistor seconds and read module.Sensing element is in order to according to sensing result output sensing voltage.Sensing crystal
Pipe comprises first end, the second end receiving the first reference voltage, and is electrically coupled to sensing element, in order to self-inductance measurement unit
Part receives the control end of sensing voltage.The first transistor comprise to be electrically coupled to sensing transistor second end first end, in order to
Receive the second end of the second reference voltage, and the control end being electrically coupled to the first transistor first end.Transistor seconds bag
Containing first end, the second end in order to receive the second reference voltage, and the control end being electrically coupled to the first transistor control end.
Read module comprises input and outfan.The voltage level of the input of read module and the first reference voltage substantially phase
With.The outfan of read module is in order to according to sensing voltage output one output voltage signal.
The another aspect of present invention is the control method of sensing circuit.Control method comprises by offer sensing module ginseng
Examine voltage；Output current is correspondingly exported in the outfan of sensing module according to sensing voltage；Sensing is controlled by read module
The voltage level of the outfan of module, makes the voltage level of the outfan of sensing module roughly the same with reference voltage；And root
According to output current, one output voltage signal is exported by this read module.
Brief description
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 unit
140 read modules
300th, 400,500,600,700 sensing circuit
322nd, 522,622,722 current lens unit
800 control methods
S810～s840 step
Q1 sensing transistor
Q2, q3, q4 transistor
Op1 operational amplifier
S1 switchs
C1 electric capacity
R1, r2, r3 resistance
N1, n2 node
Vdd, vss reference voltage
Vp senses voltage
Vo output voltage signal
I1 reference current
I2 output current
Clk clock signal
Specific embodiment
Hereafter elaborate for embodiment cooperation institute accompanying drawings, to more fully understand the aspect of present invention, but institute
The embodiment of offer is simultaneously not used to limit the scope that the present invention is covered, and the description of structure operation is not used to limit its execution
Sequentially, any structure being reconfigured by element, is produced the device of the effects such as have equal, is all the model that the present invention is covered
Enclose.Additionally, according to the standard of industry and practice, schema is only for the purpose of aiding in illustrating, and not according to life size mapping, real
On border, the size of various features can arbitrarily increase or decrease in order to illustrate.In the description below, similar elements will be accorded with identical
Number sign is illustrating in order to understand.
The word (terms) being used in full piece description and claim, in addition to having and especially indicating, generally has
Each word using in this area, here invention content in special content in usual meaning.Some in order to describe this
The word of invention discusses by lower or in the other places of this description, to provide those skilled in the art in description for the present invention
Upper extra guiding.
Additionally, the word "comprising" herein being used, " inclusion ", " having ", " containing " etc., be opening
Term, that is, mean " including but not limited to ".Additionally, used herein " and/or ", comprise one or many in associated listed items
Any one and its all combination of individual project.
In this article, when an element is referred to as " connection " or " coupling ", " electric connection " or " electric property coupling " can be referred to.
" connection " or " coupling " also may be used to represent and be collocated with each other operation or interactive between two or multiple element.In addition although making herein
With " first ", " second " ... wait term to describe different elements, this term be only distinguish with constructed term description unit
Part or operation.Unless context understands indicated, otherwise this term is not especially censured or hint order or cis-position, is also not used to limit
Determine the present invention.
Refer to Fig. 1.Fig. 1 is the schematic diagram of the sensing circuit 100 according to depicted in present invention section Example.As
Shown in Fig. 1, in some embodiments, sensing circuit 100 comprises sensing element 110, sensing module 120 and read module 140.
In structure, the outfan of the input electric property coupling sensing element 110 of sensing module 120.The input electricity of read module 140
Property couples the outfan of sensing module 120.By the cooperating of sensing module 120 and read module 140, sensing circuit 100
Output voltage signal vo can correspondingly be provided according to the sensing voltage vp of sensing element 110 output.Specifically, implement in part
In example, sensing module 120 is in order to receive sensing voltage vp from input, and correspondingly produces output current i2 from outfan.Read
Delivery block 140 is in order to receive output current i2 from input, and exports above-mentioned output voltage signal vo from outfan.
For example, in some embodiments, sensing element 110 can be the such as piezoelectric polyvinylidene fluoride by piezoelectric
(pvdf) high molecular polymer etc., made piezoelectric membrane sensor.Sensing element 110 corresponds to pressure output sensing electricity
After pressure 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 comprise sensing transistor q1 and current lens unit
122.In structure, the first end of sensing transistor q1 is electrical in order to receive reference voltage vdd, second end of sensing transistor q1
It is coupled to the reference arm of current lens unit 122, the control end of sensing transistor q1 is in order to receive sensing voltage vp.Consequently, it is possible to
Sensing transistor q1 just can export reference current i1 to the ginseng of current lens unit 122 according to reference voltage vdd with sensing voltage vp
Examine arm.
In some embodiments, current lens unit 122 comprises 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.The first end of transistor q2 is electrically coupled to the of sensing transistor q1
Two ends, second end of transistor q2 is electrically coupled to earth terminal, in order to receive reference voltage vss, the first end electricity of transistor q3
Property is coupled to the outfan (that is: node n1) of sensing module, and second end of transistor q3 is electrically coupled to earth terminal, in order to receive
Reference voltage vss.The control end of transistor q2, q3 electric property coupling each other, and it is electrically coupled to the first end of transistor q2, with shape
Become current mirroring circuit.As illustrated, in some embodiments, due to first end and the control end electrical coupling each other of transistor q2
Connect, the gate-source voltage of transistor q2 is the first end of transistor q2 and the pressure reduction of reference voltage vss.When sensing voltage vp carries
Gao Shi, the voltage level with second end of sensing transistor q1 improves, and the gate-source voltage of transistor q2 also improves therewith, makes
Obtain reference current i1 to improve therewith.Consequently, it is possible to flow through the transistor on the reference arm of current lens unit 122 as reference current i1
During q2, output current i2 corresponding to reference current i1 will be had on the output arm of current lens unit 122 to produce 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 repeats no more in this.
Thereby, by the operation of sensing transistor q1 and current lens unit 122, sensing module 120 just can be by sensing element
The sensing voltage vp of 110 outputs is converted to suitable current signal (that is: output current i2) to read module 140.For example,
In some embodiments, the current value of reference current i1 can be amplified by current lens unit 122 produces output current i2 to scale.
Even if consequently, it is possible to the reference of sensing voltage vp generation corresponding to current lens unit 122 reference side that sensing element 110 is exported
Electric current i1 only has minor variations, and current lens unit 122 outlet side maps output current i2 producing and according to output current i2
The output voltage signal vo producing still can represent detected pressure size, it is to avoid the environment noise on circuit and back-end circuit
Interference leads to process circuit to be judged by accident.Thereby, sensing circuit 100 can lift sensitivity and the accuracy of sensing.
As shown in figure 1, in some embodiments, read module 140 comprise operational amplifier op1, resistance r1, electric capacity c1 with
And switch s1.In structure, operational amplifier op1 comprises first input end (such as: negative pole end), the second input (such as: positive pole
End) and outfan, wherein first input end is electrically coupled to the input (that is: node n1) of read module 140, the second input
In order to receive reference voltage vdd, outfan is in order to export an output voltage signal vo at end.Resistance r1, electric capacity c1 and switch s1
It is electrically coupled between first outfan of operational amplifier op1 and outfan.In other words, resistance r1, electric capacity c1 and switch
S1 with parallel form electric property coupling, forms the feedback circuit of operational amplifier op1 each other.Assume the input of operational amplifier op1
Impedance is sufficiently large, then the first input end of operational amplifier op1 and the second input are imaginary short (virtual short), greatly
Cause has same voltage level.Consequently, it is possible to because second input of operational amplifier op1 receives reference voltage vdd, therefore
The voltage level of node n1 is just roughly the same with reference voltage vdd.
In some embodiments, switch s1 in order to receive clock signal clk, and optionally led according to clock signal clk
Logical.When switching s1 conducting, the feedback impedance of amplifier circuit is zero, and read module 140 can be considered voltage follower so that defeated
Go out voltage signal vo and there is the voltage level substantially the same with reference voltage vdd.
Relatively, when switching s1 cut-off, the feedback circuit of amplifier circuit is the resistance r1 and electric capacity c1 being connected in parallel to each other.
Because output current i2 of sensing module 120 output flows through resistance r1, the therefore voltage level of output voltage signal vo is (vdd+
i2·r1).Because the size of current of output current i2 corresponds to sensing voltage vp, therefore output voltage signal vo also corresponds to sense
Survey voltage vp, consequently, it is possible to according to output voltage signal vo, the process circuit of rear end just can judge that sensing element 110 is sensed
Pressure size.In some embodiments, electric capacity c1 can filter the exchange vibration in output voltage signal vo as filter element
Composition, to avoid back-end circuit erroneous judgement signal.
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 understanding explanation, depicted voltage waveform in Fig. 2 coordinates the sensing circuit 100 in embodiment illustrated in fig. 1 to illustrate,
But and it is not used to limit present invention.
As shown in Fig. 2 in some embodiments, after sensing element 110 senses pressure, the sensing voltage vp of its output
There is specific voltage swing and waveform corresponding to pressure size.When clock signal clk is in high level, switch s1 leads
Logical, output voltage signal vo is a low level definite value (such as: reference voltage vdd).Relatively, when clock signal clk be in low
During level, switch s1 cut-off, output voltage signal vo will have voltage swing and waveform corresponding to sensing voltage vp.(such as:
vdd+i2·r1).Consequently, it is possible to read module 140 just can carry out sample of signal according to clock signal clk, 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 input of delivery block 140 substantially maintains reference voltage with the voltage level of the node n1 of outfan of sensing module 120
vdd.Thereby, the reference current i1 of current lens unit 122 reference side just can map to output current i2 of outlet side exactly.
Specifically, when when between the drain-source of transistor q2, q3, voltage mismatches, the passage length modulation effect of transistor
(channel length modulation effect), can lead to reference current i1 and the proportionate relationship of output current i2 to have
Error.The relational expression of output current i2 and reference current i1 can be expressed from the next:
Wherein wq2、wq3Represent grid width, the l of transistor q2, q3 respectivelyq2、lq3Represent the grid of transistor q2, q3 respectively
Pole length, vdsq2、vdsq3Represent voltage between the drain-source of transistor q2, q3 respectively, λ represents passage length modulation effect coefficient.
, by the voltage level of control node n1, between the drain-source of controllable transistor q3, voltage is (i.e.: for sensing circuit 100
vdsq3), and reduce because voltage mismatches phenomenon between the drain-source of node n1 voltage floating led to transistor q2, q3.Such one
Come, output current i2 also decreases the entirety sensing precision so that sensing circuit 100 with the error of output voltage signal vo
Lifting.
Sensing module 120 depicted in FIG is only signal and is used, and is not used to limit this case.In present invention
In each embodiment, sensing module 120 can be by different circuit realiration, and corresponding schema of arranging in pairs or groups is illustrated by paragraphs below.
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 the embodiment of Fig. 1 represent with the same references in order to understand, and similar finite element
The concrete principle of part describes in detail in previous paragraph, if not having Collaboration relation and necessary Jie with the interelement of Fig. 3
The person of continuing, repeats no more in this.In embodiment depicted in Fig. 3, compared with the sensing circuit 100 depicted in Fig. 1, current mirror list
Transistor q2, q3 in unit 322 can be p-type metal oxide semiconductor field-effect transistor (p-type metal-oxide-
Semiconductor field-effect transistor, pmosfet, pmos).
Additionally, in the embodiment shown in fig. 3, the first end of sensing transistor q1 is electrically coupled to earth terminal, in order to receive
Reference voltage vss, second end of sensing transistor q1 is electrically coupled to the reference arm of current lens unit 322, sensing transistor q1
Control end in order to receive sensing voltage vp, with according to reference voltage vss with sensing voltage vp output reference current i1 to electric current
The reference arm of mirror unit 322.
In structure, the first end of transistor q2 is electrically coupled to second end of sensing transistor q1, and the of transistor q2
Two ends are electrically coupled to outfan (that is: the node of sensing module 120 in order to receive reference voltage vdd, the first end of transistor q3
N1), second end of transistor q3 is in order to receive reference voltage vdd.The control end of transistor q2, q3 electric property coupling each other, and electricity
Property is coupled to the first end of transistor q2, to form current mirroring circuit.
Consequently, it is possible to it is similar to depicted current lens unit 122 in Fig. 1, when reference current i1 flows through current lens unit
During transistor q2 on 322 reference arm, will have defeated corresponding to reference current i1 on the output arm of current lens unit 322
Go out electric current i2 to produce and flow through transistor q3.
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 the embodiment of Fig. 1 represent with the same references in order to understand, and similar finite element
The concrete principle of part describes in detail in previous paragraph, if not having Collaboration relation and necessary Jie with the interelement of Fig. 4
The person of continuing, repeats no more in this.In embodiment depicted in Fig. 4, compared with the sensing circuit 100 depicted in Fig. 1, read module
140 further include resistance r2, the r3 contacting each other.In structure, the first end of resistance r2 is in order to receiving voltage vin, resistance r2's
Second end is electrically coupled to second input (such as: electrode input end) of operational amplifier op1 and the first end of resistance r3.Electricity
Second end of resistance r3 is electrically coupled to earth terminal.
Consequently, it is possible to by the partial pressure of resistance r2, r3, second input (such as: electrode input end) of operational amplifier op1
Just it is operable in suitable voltage level so that the voltage level of the second input (such as: electrode input end) and reference voltage vdd
Roughly the same.For example, in some embodiments, the voltage level of second input of operational amplifier op1 is vin.
[(r3)/(r2+r3)].In other words, by adjusting the resistance of resistance r2, r3, just can control second input of operational amplifier op1
The voltage level at end is roughly the same with reference voltage vdd, and then makes the voltage level of node n1 and the reference voltage of imaginary short
Vdd is roughly the same.
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 the embodiment of Fig. 1 represent with the same references in order to understand, and similar finite element
The concrete principle of part describes in detail in previous paragraph, if not having Collaboration relation and necessary Jie with the interelement of Fig. 5
The person of continuing, repeats no more in this.In embodiment depicted in Fig. 5, compared with the sensing circuit 100 depicted in Fig. 1, current mirror list
Unit 522 comprises transistor q2, q3, q4.In some embodiments, transistor q2, q3, q4 can be nmos.
In structure, the first end of transistor q2 is electrically coupled to second end of sensing transistor q1, and the of transistor q2
Two ends are in order to receive reference voltage vss.The first end of transistor q3 is electrically coupled to second end of transistor q4, transistor q3's
Second end is electrically coupled to second end of transistor q2, in order to receive reference voltage vdd.The control end of transistor q2, q3 is each other
Electric property coupling, and it is electrically coupled to the first end of transistor q2.The first end of transistor q4 is electrically coupled to sensing module 120
Outfan (that is: node n2), the control end of transistor q4 is electrically coupled to the control end of sensing transistor q1, in order to receive sensing
Voltage vp, to form current mirroring circuit.
Consequently, it is possible to it is similar to depicted current lens unit 122 in Fig. 1, when reference current i1 flows through current lens unit
During transistor q2 on 522 reference arm, will have defeated corresponding to 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.
Similar to previous embodiment, electrode input end and negative input due to operational amplifier op1 are imaginary short
(virtual short), therefore the voltage level of node n2 is just roughly the same with reference voltage vdd.Consequently, it is possible to sensing module
Sensing transistor q1 in 120 and transistor q4 is mutually symmetrical, and transistor q2 is mutually symmetrical with transistor q3, just can drop further
Because voltage mismatches on low current mirror unit 522 reference arm and output arm, the electric current being led to by passage length modulation effect misses
Difference.In other words, by arranging transistor q4 corresponding with sensing transistor q1, reference current i1 and output electricity can be reduced further
Error between stream i2.
Specifically, compare with embodiment illustrated in fig. 1, the voltage level of node n1 and reference voltage vdd be substantially in FIG
Identical.However, the pressure drop being led to by sensing transistor q1 itself so that actually between the drain-source of transistor q2 voltage with brilliant
Voltage non-fully mating between the drain-source of body pipe q3.Consequently, it is possible to due to the passage length modulation effect of transistor, can lead to join
The proportionate relationship examining electric current i1 with output current i2 still has error.Relatively, in Figure 5, the voltage level of node n2 and ginseng
Examine voltage vdd roughly the same.Due to being provided with transistor q4 corresponding with sensing transistor q1 in current mirroring circuit 522, therefore
The pressure drop that the pressure drop that on reference arm, sensing transistor q1 is led to is led to transistor q4 on output arm is identical.Consequently, it is possible to
Between the drain-source of transistor q2, between the drain-source of voltage and transistor q3, voltage is just roughly the same.Thereby, electricity on reference arm and output arm
Press unmatched phenomenon can obtain improvement, and then reduce the error of reference current i1 and output current i2.
Thereby, read module 140 just can be more accurate according to the output voltage signal vo that output current i2 is exported, to carry
Rise the accuracy that sensing circuit 100 senses pressure.
In addition although in embodiment depicted in Fig. 5, sensing transistor q1 and transistor q2～q4 is all isomrophous crystal
Pipe (such as: N-shaped MOS transistor), but present invention is not limited thereto.Refer to Fig. 6.Fig. 6 is according to present invention
The schematic diagram of the sensing circuit 600 depicted in other parts embodiment.In Fig. 6, similar components relevant with the embodiment of Fig. 5
Represent with the same references in order to understand, and the concrete principle of similar components describes in detail in previous paragraph, if
Non- have Collaboration relation with Fig. 5 interelement and necessity person of introduction, repeats no more in this.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-shaped gold oxygen semi-crystal
Pipe, the transistor q4 in current lens unit 622 and sensing transistor q1 is p-type MOS transistor.In other words, partly real
Apply in example, transistor q2, q3 can be the first transistor npn npn, transistor q4 and sensing transistor q1 can be for being different from the first type crystal
Second transistor npn npn of pipe.
Additionally, in some embodiments, sensing transistor q1 and transistor q2～q4 also can be all p-type gold oxygen semi-crystal
Pipe.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 the embodiment of Fig. 5 represent with the same references in order to understand, and similar components
Concrete principle describes in detail in previous paragraph, if not there is Collaboration relation and necessity person of introduction with the interelement of Fig. 5,
Repeat no more in this.
In embodiment depicted in Fig. 7, compared with the sensing circuit 500 depicted in Fig. 5, sensing transistor q1 and electricity
Transistor q2, q3, q4 in stream mirror unit 722 is p-type MOS transistor.
Similar with depicted embodiment in Fig. 3, electrode input end and negative input due to operational amplifier op1 are
The characteristic of imaginary short, the voltage level of node n2 is 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, just can reduce further with reference to electricity
Error between stream i1 and output current i2, its concrete principle is similar to previous embodiment, and in previous paragraph specifically
Bright, therefore repeat no more in this.
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 depicted senses in cooperation Fig. 1～Fig. 7 embodiment
Slowdown monitoring circuit 100,300～700 illustrates, but is not limited, and any is familiar with this those skilled in the art, without departing from present invention
In spirit and scope, when can to make various change with retouching.As shown in figure 8, control method 800 comprise step s810, s820,
S830 and s840.
First, in step s810, reference voltage (such as: reference voltage vdd) is received by sensing module 120.
Then, in step s820, electricity is correspondingly exported in the outfan of sensing module 120 according to sensing voltage vp
Stream i2.Specifically, in some embodiments, the step of output output current i2 can comprise by sensing transistor q1 according to reference
Voltage (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, controlled voltage level and the ginseng of the outfan of sensing module 120 by read module 140
Examine voltage (such as: reference voltage vdd or reference voltage vss) roughly the same.Specifically, in some embodiments, control sensing
The voltage level of the outfan of module 120 comprises by first input end (such as: the negative input) Perceived control of operational amplifier op1
Survey the voltage level of the outfan of module 120, and connect by second input (such as: electrode input end) of operational amplifier op1
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 exporting above-mentioned output voltage signal vo further includes by switch s1 according to clock signal
Clk selectively turns on the first input end of operational amplifier op1 and the outfan of operational amplifier op1.When switch s1 turns off
When, the output voltage signal vo of sensing voltage vp is corresponded to by the outfan output of operational amplifier op1.When switch s1 conducting
When, be there is the output voltage signal vo of low level (such as: reference voltage vdd) by the outfan output of operational amplifier op1.
Consequently, it is possible to read module 140 just can carry out sample of signal output voltage signal vo according to clock signal clk,
The process circuit of rear end just can judge, according to output voltage signal vo, the pressure size that sensing element 110 is sensed.
Although it should be noted that herein disclosed method is shown and described as a series of step or event,
It is it should be appreciated that the order of these shown steps or event should not be construed as limited significance.For example, part steps can be with
Different order occurs and/or same with other steps in addition to illustrated herein and/or described step or event or event
Shi Fasheng.In addition, when implementing one or more aspects described herein or embodiment, and step shown in this for the not all is all
For required.Additionally, one or more steps herein also may be held in one or more detached steps 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 execute the operation such as this and function, therefore no longer this repeats.
In sum, in each embodiment of present invention, sensing circuit passes through the imaginary short characteristic of operational amplifier,
By the voltage level of node at sensing module and read module electric property coupling control with sensing transistor identical reference voltage,
The sensing transistor in sensing module and the transistor in current lens unit can be made to have symmetrical passage length modulation effect
Should, to reduce produced signal errors when reference current is mapped generation output current by current lens unit.Consequently, it is possible to read
Module just can have higher accuracy according to the output voltage signal that output current exports.
Additionally, in some embodiments, current lens unit can comprise the transistor corresponding to sensing transistor so that sensing
Transistor in module is mutually symmetrical, and reduces signal errors further.
It should be noted that in the case of not conflicting, in each schema of present invention, embodiment and embodiment
Feature can be mutually combined with circuit.In schema, depicted circuit is merely illustrative is used, and simplifies so that interest of clarity being 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
Practise this those skilled in the art, in the spirit and scope without departing from present invention, when can make various change with retouching, therefore in the present invention
The protection domain holding ought be defined depending on the defined person of appended claims.
Claims (13)
1. a kind of sensing circuit is it is characterised in that comprise:
One sensing module, in order to receive a sensing voltage and correspondingly to export an output current, this sensing module comprises:
One sensing transistor, in order to receive a reference voltage, this sensing transistor is in order to root for a first end of this sensing transistor
According to this reference voltage and this sensing voltage output one reference current；And
One current lens unit, this sensing transistor of electric property coupling, export this output current in order to map according to this reference current；With
And
One read module, this read module and this sensing module are electrically coupled to a node, and export one according to this output current
The voltage level of output voltage signal, wherein this node is roughly the same with this reference voltage.
2. sensing circuit according to claim 1 is it is characterised in that this read module comprises:
One operational amplifier, comprises:
One first input end, is electrically coupled to this node；
One second input, in order to receive this reference voltage；And
One outfan, in order to export this output voltage signal；And
One first resistor, is electrically coupled between this first input end of this operational amplifier and this outfan.
3. sensing circuit according to claim 2 is it is characterised in that this read module further includes:
One first switch, is electrically coupled between this first input end of this operational amplifier and this outfan, this first switch
In order to be turned on according to a seasonal pulse signal-selectivity.
4. sensing circuit according to claim 3 is it is characterised in that when this first switch turns on, this output voltage is believed
Number there is a low level, when this first switch turns off, this output voltage signal corresponds to this sensing voltage.
5. sensing circuit according to claim 1 is it is characterised in that a control end of this sensing transistor is in order to receive this
Sensing voltage, this current lens unit comprises:
One the first transistor, comprises:
One first end, is electrically coupled to one second end of this sensing transistor；
One second end；And
One control end, is electrically coupled to this first end of this first transistor；And
One transistor seconds, comprises:
One first end, is electrically coupled to this node；
One second end, is electrically coupled to this second end of this first transistor；And
One control end, is electrically coupled to this control end of this first transistor.
6. sensing circuit according to claim 1 is it is characterised in that a control end of this sensing transistor is in order to receive this
Sensing voltage, this current lens unit comprises:
One the first transistor, comprises:
One first end, is electrically coupled to one second end of this sensing transistor；
One second end；And
One control end, is electrically coupled to this first end of this first transistor；
One transistor seconds, comprises:
One first end；
One second end, is electrically coupled to this second end of this first transistor；And
One control end, is electrically coupled to this control end of this first transistor；And
One third transistor, comprises:
One first end, is electrically coupled to this node；
One second end, is electrically coupled to this first end of this transistor seconds；And
One control end, is electrically coupled to this control end of this sensing transistor.
7. a kind of sensing circuit is it is characterised in that comprise:
One sensing element, in order to according to sensing result output one sensing voltage；
One sensing transistor, comprises:
One first end, in order to receive one first reference voltage；
One second end；And
One control end, is electrically coupled to this sensing element, in order to receive this sensing voltage from this sensing element；
One the first transistor, comprises:
One first end, is electrically coupled to this second end of this sensing transistor；
One second end, in order to receive one second reference voltage；And
One control end, is electrically coupled to this first end of this first transistor；
One transistor seconds, comprises:
One first end；
One second end, in order to receive this second reference voltage；And
One control end, is electrically coupled to this control end of this first transistor；And
One read module, comprises:
One input, the voltage level of this input is roughly the same with this first reference voltage；And
One outfan, in order to according to this sensing voltage output one output voltage signal.
8. sensing circuit according to claim 7 is it is characterised in that this first end of this transistor seconds is electrically coupled to
This input of this read module, this read module comprises:
One operational amplifier, comprises:
One first input end, is electrically coupled to this input of this read module；
One second input, in order to receive this first reference voltage；And
One outfan, in order to export this output voltage signal；
One first resistor, is electrically coupled between this first input end of this operational amplifier and this outfan；And
One first switch, is electrically coupled between this first input end of this operational amplifier and this outfan.
9. sensing circuit according to claim 7 is it is characterised in that further include:
One third transistor, comprises:
One first end, is electrically coupled to this input of this read module；
One second end, is electrically coupled to this first end of this transistor seconds；And
One control end, is electrically coupled to this control end of this sensing transistor.
10. a kind of control method of sensing circuit is it is characterised in that comprise:
One sensing module one reference voltage is provided；
One output current is correspondingly exported in an outfan of this sensing module according to a sensing voltage；
Control the voltage level of this outfan of this sensing module by a read module, make this outfan of this sensing module
Voltage level is roughly the same with this reference voltage；And
One output voltage signal is exported by this read module according to this output current.
11. control methods according to claim 10 comprise it is characterised in that exporting this output current:
By a sensing transistor according to this reference voltage and this sensing voltage output one reference current；And
Mapped according to this reference current by a current lens unit and export this output current.
12. control methods according to claim 10 are it is characterised in that control the voltage of this outfan of this sensing module
Level comprises:
Control the voltage level of this outfan of this sensing module by a first input end of an operational amplifier；And
One second input providing this operational amplifier receives this reference voltage.
13. control methods according to claim 12 further include it is characterised in that exporting this output voltage signal:
This first input end of this operational amplifier and this fortune are turned on according to a seasonal pulse signal-selectivity by a first switch
Calculate an outfan of amplifier；And
When this first switch turns off, this outfan output by this operational amplifier is electric corresponding to this output of this sensing voltage
Pressure 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 |
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| CN106354187A true CN106354187A (en) | 2017-01-25 |
| CN106354187B CN106354187B (en) | 2018-04-06 |
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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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| CN (1) | CN106354187B (en) |
| TW (1) | TWI638145B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108777150A (en) * | 2018-05-02 | 2018-11-09 | 友达光电股份有限公司 | Sensing circuit |
| CN109965854A (en) * | 2018-08-29 | 2019-07-05 | 友达光电股份有限公司 | Sensing part and pulse condition measurement method |
| CN112904923A (en) * | 2019-12-03 | 2021-06-04 | 瑞昱半导体股份有限公司 | Current generating circuit |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
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| CN1269632A (en) * | 1998-10-30 | 2000-10-11 | 英特赛尔公司 | Overcurrent sensing circuit and self-regulating blankoff |
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| CN108777150B (en) * | 2018-05-02 | 2021-02-23 | 友达光电股份有限公司 | Sensing circuit |
| CN109965854A (en) * | 2018-08-29 | 2019-07-05 | 友达光电股份有限公司 | Sensing part and pulse condition measurement method |
| CN112904923A (en) * | 2019-12-03 | 2021-06-04 | 瑞昱半导体股份有限公司 | Current generating circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106354187B (en) | 2018-04-06 |
| TW201800722A (en) | 2018-01-01 |
| TWI638145B (en) | 2018-10-11 |
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