CN107167664A - A kind of capacitive detection circuit - Google Patents
A kind of capacitive detection circuit Download PDFInfo
- Publication number
- CN107167664A CN107167664A CN201710314877.1A CN201710314877A CN107167664A CN 107167664 A CN107167664 A CN 107167664A CN 201710314877 A CN201710314877 A CN 201710314877A CN 107167664 A CN107167664 A CN 107167664A
- Authority
- CN
- China
- Prior art keywords
- counter
- switch
- electric capacity
- data processing
- detection circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/26—Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants ; Measuring impedance or related variables
- G01R27/2605—Measuring capacitance
Abstract
The invention provides a kind of capacitive detection circuit, belong to semiconductor integrated circuit technical field.The circuit includes detection electric capacity, reference capacitance, first switch and second switch, comparator, oscillator, counter and data processing unit；First switch one terminates input voltage, one end of another termination detection electric capacity and one end of second switch；Detect the other end ground connection of electric capacity；One end of another termination reference capacitance of second switch and the positive input terminal of comparator；The other end ground connection of reference capacitance；The negative input of comparator terminates half input voltage, the Enable Pin of the output termination counter of comparator；The input of counter connects the output of oscillator, and the output access data processing module of counter carries out data processing.Compared to traditional capacitive detection circuit, capacitive detection circuit of the invention has precision high, and the characteristics of strong antijamming capability.
Description
Technical field
The invention belongs to semiconductor integrated circuit technical field, and in particular to a kind of capacitive detection circuit.
Background technology
The life that the capacitive touch technology of current fast development gives people brings many facilities, and touch key-press is wide
The general every aspect for being applied to the lives such as desk lamp, refrigerator, so judging whether to touch by detecting the size of capacitance
Capacitive detection circuit just become more and more important.
Traditional capacitance measurement technique is all by the way that electric capacity is placed in RC oscillators, by detecting RC oscillator frequencies
Change to judge the change of capacitance.
This traditional detection method is low to the accuracy of detection of electric capacity, and antijamming capability is weak.
The content of the invention
To solve the existing technical problem that capacitive detection circuit accuracy of detection is low, antijamming capability is weak, the invention provides
A kind of accuracy of detection is high, the capacitive detection circuit of strong antijamming capability.
A kind of capacitive detection circuit, including：Detect electric capacity CX, reference capacitance CR, first switch S1 and second switch S2, ratio
Compared with device COMP, oscillator OSC, counter Counter and data processing unit Dataprocessing；First switch S1 one end
Meet input voltage VREF, another termination detection electric capacity CXOne end and second switch S2 one end；Detect electric capacity CXAnother termination
Ground；Second switch S2 another termination reference capacitance CROne end and comparator COMP positive input terminal；Reference capacitance CRIt is another
End ground connection；Comparator COMP negative input terminates half input voltage 1/2VREF, comparator COMP output termination counter
Counter Enable Pin EN；Counter Counter input connects oscillator OSC output, and counter Counter output connects
Enter data processing module Date processing and carry out data processing.
The capacitive detection circuit of the present invention, first will detection electric capacity CXVoltage be charged to input voltage VREF, then again will inspection
Survey electric capacity CXWith reference capacitance CRElectric charge is shared, so after some cycles, reference capacitance CROn voltage can be gradually increasing,
To reference capacitance CRVoltage rises to 1/2VREFAfterwards, comparator COMP is overturn, and at this time rolling counters forward terminates.So, count
The size of value is just with detecting electric capacity CXOne-to-one relation is formed, the change of count value also just embodies detection electric capacity CXChange
Change, so as to form with the capacitive detection circuit compared with high measurement accuracy, and with stronger antijamming capability.
Brief description of the drawings
Fig. 1 is the capacitive detection circuit structural representation that first embodiment of the invention is provided.
Embodiment
To make the object, technical solutions and advantages of the present invention of greater clarity, with reference to embodiment and join
According to accompanying drawing, the present invention is described in more detail.It should be understood that these descriptions are merely illustrative, and it is not intended to limit this hair
Bright scope.In addition, in the following description, the description to known features and technology is eliminated, to avoid unnecessarily obscuring this
The concept of invention.
Traditional capacitance measurement technique is by the way that electric capacity is placed in RC oscillators, by detecting RC oscillator frequencies
Change judges the change of capacitance, so as to cause that the accuracy of detection to electric capacity is low, antijamming capability is weak.
The accuracy of detection and antijamming capability of capacitance measurement technique are how improved, is those skilled in the art's technology urgently to be resolved hurrily
Problem.
By many-side research, the present invention overturn traditional capacitance measurement technique there is provided a kind of new accuracy of detection it is high,
The capacitive detection circuit of strong antijamming capability, as shown in figure 1, the capacitive detection circuit includes：Detect electric capacity CX, reference capacitance CR、
First switch S1 and second switch S2, comparator COMP, oscillator OSC, counter Counter and data processing unit Data
processing.The termination input voltages of first switch S1 mono- VREF, another termination detection electric capacity CXOne end and second switch S2
One end；Detect electric capacity CXThe other end ground connection；Second switch S2 another termination reference capacitance CROne end and comparator COMP
Positive input terminal；Reference capacitance CRThe other end ground connection；Comparator COMP negative input terminates half input voltage 1/2VREF, comparator
COMP output termination counter Counter Enable Pin EN；Counter Counter input connects oscillator OSC output, meter
Number device Counter output access data processing module Date processing carry out data processing.
The capacitive detection circuit of the present invention, first will detection electric capacity CXVoltage be charged to input voltage VREF, then again will inspection
Survey electric capacity CXWith reference capacitance CRElectric charge is shared, so after some cycles, reference capacitance CROn voltage can be gradually increasing,
To reference capacitance CRVoltage rises to 1/2VREFAfterwards, comparator COMP is overturn, and at this time rolling counters forward terminates.So, count
The size of value is just with detecting electric capacity CXOne-to-one relation is formed, the change of count value also just embodies detection electric capacity CXChange
Change, the capacitive detection circuit with compared with high measurement accuracy is formd, with stronger antijamming capability.
In the present invention, half input voltage 1/2VREFFor input voltage VREFThe half size of value.
It should be appreciated that the above-mentioned embodiment of the present invention is used only for exemplary illustration or explains the present invention's
Principle, without being construed as limiting the invention.Therefore, that is done without departing from the spirit and scope of the present invention is any
Modification, equivalent substitution, improvement etc., should be included in the scope of the protection.In addition, appended claims purport of the present invention
Covering the whole changes fallen into scope and border or this scope and the equivalents on border and repairing
Change example.
Claims (1)
1. a kind of capacitive detection circuit, it is characterised in that including：Detect electric capacity CX, reference capacitance CR, first switch S1 and second
Switch S2, comparator COMP, oscillator OSC, counter Counter and data processing unit Data process ing；The
The one switch termination input voltages of S1 mono- VREF, another termination detection electric capacity CXOne end and second switch S2 one end；Detect electric capacity
CXThe other end ground connection；Second switch S2 another termination reference capacitance CROne end and comparator COMP positive input terminal；Benchmark
Electric capacity CRThe other end ground connection；Comparator COMP negative input terminates half input voltage 1/2VREF, comparator COMP output end
Meet counter Counter Enable Pin EN；Counter Counter input connects oscillator OSC output, counter Counter
Output access data processing module Date process ing carry out data processing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710314877.1A CN107167664A (en) | 2017-05-07 | 2017-05-07 | A kind of capacitive detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710314877.1A CN107167664A (en) | 2017-05-07 | 2017-05-07 | A kind of capacitive detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107167664A true CN107167664A (en) | 2017-09-15 |
Family
ID=59812754
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710314877.1A Pending CN107167664A (en) | 2017-05-07 | 2017-05-07 | A kind of capacitive detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107167664A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107633230A (en) * | 2017-09-22 | 2018-01-26 | 重庆纳尔利科技有限公司 | A kind of efficiently finger capacitive detection circuit |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1766660A (en) * | 2004-09-08 | 2006-05-03 | 欧姆龙株式会社 | Capacitance measuring arrangement, method, and program |
| CN101315398A (en) * | 2007-05-28 | 2008-12-03 | 承永资讯科技股份有限公司 | Capacitance value measuring apparatus and method |
| CN101556297A (en) * | 2008-04-08 | 2009-10-14 | 瑞鼎科技股份有限公司 | Capacitance value measuring circuit and measuring method thereof |
| CN101738544A (en) * | 2008-11-17 | 2010-06-16 | 瑞鼎科技股份有限公司 | Capacitance measurement circuit and capacitance measurement method |
| CN203117298U (en) * | 2013-01-30 | 2013-08-07 | 比亚迪股份有限公司 | Capacitance detection circuit |
| CN104238840A (en) * | 2013-06-24 | 2014-12-24 | 原相科技股份有限公司 | Capacitor detecting circuit, power supply device and optical touch device |
-
2017
- 2017-05-07 CN CN201710314877.1A patent/CN107167664A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1766660A (en) * | 2004-09-08 | 2006-05-03 | 欧姆龙株式会社 | Capacitance measuring arrangement, method, and program |
| CN101315398A (en) * | 2007-05-28 | 2008-12-03 | 承永资讯科技股份有限公司 | Capacitance value measuring apparatus and method |
| CN101556297A (en) * | 2008-04-08 | 2009-10-14 | 瑞鼎科技股份有限公司 | Capacitance value measuring circuit and measuring method thereof |
| CN101738544A (en) * | 2008-11-17 | 2010-06-16 | 瑞鼎科技股份有限公司 | Capacitance measurement circuit and capacitance measurement method |
| CN203117298U (en) * | 2013-01-30 | 2013-08-07 | 比亚迪股份有限公司 | Capacitance detection circuit |
| CN104238840A (en) * | 2013-06-24 | 2014-12-24 | 原相科技股份有限公司 | Capacitor detecting circuit, power supply device and optical touch device |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107633230A (en) * | 2017-09-22 | 2018-01-26 | 重庆纳尔利科技有限公司 | A kind of efficiently finger capacitive detection circuit |
| CN107633230B (en) * | 2017-09-22 | 2021-07-09 | 重庆纳尔利科技有限公司 | High-efficient finger capacitance detection circuit |
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| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20170915 |
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| WD01 | Invention patent application deemed withdrawn after publication |