CN107192850A - A kind of accelerometer capacitive detection circuit - Google Patents
A kind of accelerometer capacitive detection circuit Download PDFInfo
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- CN107192850A CN107192850A CN201710581214.6A CN201710581214A CN107192850A CN 107192850 A CN107192850 A CN 107192850A CN 201710581214 A CN201710581214 A CN 201710581214A CN 107192850 A CN107192850 A CN 107192850A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
- G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
- G01P15/125—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by capacitive pick-up
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Abstract
The invention discloses a kind of accelerometer capacitive detection circuit, the circuit includes：Modulator structure module；Capacitance compensation array module；D/A converting circuit module；Input Common-mode compensation circuitry module, wherein, capacitance compensation array is connected to the front end of modulator block first order switched-capacitor integrator, D/A converting circuit is connected to first order switched-capacitor integrator under the control that one-bit digital is exported, input the output of Common-mode compensation circuitry sampling first order switched-capacitor integrator, try to achieve and the input of first order switched-capacitor integrator is fed back to after common-mode voltage eliminate its common mode input deviation, solve existing accelerometer capacitive detection circuit presence is easily influenceed by environment and oneself factor, and power consumption is higher, it is not easy to the technical problem of processing, realize circuit design reasonable, it is not easily susceptible to environment and the influence of itself, testing result is accurate, and the relatively low technique effect of power consumption.
Description
Technical field
The present invention relates to accelerometer research field, in particular it relates to a kind of accelerometer capacitive detection circuit.
Background technology
Current acceleration meter is widely used in automobile, industrial automation, Aero-Space and other various fields.Compared to pressure
Resistance accelerometer, capacitive accelerometer is popular with its low temperature sensitivity.In addition, with analog acceleration meter phase
Than digital accelerometer has to be selected without the extra ADC advantages that just can directly carry out error correction and compensation as main flow
Select.
Fig. 2 is traditional open loop accelerometer capacitive detection circuit, is had in traditional accelerometer capacitive detection circuit
The voltage digitizer (V/D) of two important modules, capacitance-voltage converter (C/V) and following stage.But this group
Conjunction have the shortcomings that three it is main：First, be converted to this mode of voltage and be easy to by environmental factor (such as temperature), Yi Ji electricity
The influence of road self-noise；Second, in most capacitive detection circuit, C/V modules all consume considerable power consumption, because
It is that it needs larger bandwidth and very high gain to realize the output of low noise, this is that low power dissipation design is highly undesirable.The
Three, due to that can have big process deviation in MEMS manufacturing processes, the basic electric capacity of transducer sensitive structure might have very
Big change, this will bring very big problem to front end C/V designs.
In summary, present inventor has found above-mentioned technology extremely during the present application technical scheme is realized
There is following technical problem less：
In the prior art, existing accelerometer capacitive detection circuit is present easily by environment and oneself factor shadow
Ring, the higher technical problem of power consumption.
The content of the invention
The invention provides a kind of accelerometer capacitive detection circuit, existing accelerometer capacitive detection circuit is solved
In the presence of easily being influenceed by environment and oneself factor, power consumption is higher, realizes circuit design rationally, is not easily susceptible to environment and itself
Influence, testing result is accurate, and the relatively low technique effect of power consumption.
In order to solve the above technical problems, this application provides a kind of accelerometer capacitive detection circuit, the circuit includes：
Modulator structure module；Capacitance compensation array module；D/A converting circuit module；Input Common-mode compensation circuitry mould
Block, wherein, modulator structure module is used to the change of accelerometer electric capacity being converted to numeral output, capacitance compensation array module
For offsetting the imbalance of the basic electric capacity in accelerometer sensitive structure and error, D/A converting circuit module is used to realize one digit number
Word is output to the feedback of first order switched-capacitor integrator, and input Common-mode compensation circuitry is used to eliminate first order switching capacity integration
The common mode input deviation of device；Capacitance compensation array is connected to the front end of modulator block first order switched-capacitor integrator,
D/A converting circuit is connected to first order switched-capacitor integrator under the control that one-bit digital is exported, and inputs Common-mode compensation circuitry
The output of sampling first order switched-capacitor integrator, tries to achieve the input that first order switched-capacitor integrator is fed back to after common-mode voltage
Eliminate its common mode input deviation.
Further, modulator structure module includes：Equivalent capacity Cs1, Cs2 of accelerometer sensitive structure, computing is put
Big device AMP1, AMP2, AMP3, comparator CMP, switch S1 ..., S30, electric capacity C1 ..., C14, correlated-double-sampling electric capacity Ch1,
Ch2, the first order integrator electric capacity Cf1, Cf2；
Further, capacitance compensation array module includes：Switch S31, S32 and electric capacity Cc1, Cc2.
Further, D/A converting circuit module includes：Switch S33 ..., S40 and electric capacity Cb1, Cb2.
Further, input Common-mode compensation circuitry module includes：Single end operational amplifier AMP4, switch S41 ..., S50,
Electric capacity C15, C16, Cfb1, Cfb2.
Further, operational amplifier A MP1 and switch S1 ..., S8 and electric capacity Cs1, Cs2, Ch1, Ch2, Cf1, Cf2 structure
Into first order switched-capacitor integrator；Operational amplifier A MP2 and switch S9 ..., S16 and electric capacity C1, C2, C11, C12 constitute the
Secondary switch capacitance integrator；Operational amplifier A MP3 and switch S17 ... S24 and electric capacity C3, C4, C13, C14 constitute the third level
Switched-capacitor integrator；Switch S25 ..., S30 and electric capacity C5 ..., C10 constitute summing circuit；Comparator CMP is used as an amount
Change device；Switch S31, S32 and electric capacity Cc1, Cc2 formation base capacitor compensating circuit；Switch S33 ..., S40 and electric capacity Cb1, Cb2
Constitute the negative-feedback that modulator is output to first switch electric capacity；Operational amplifier A MP4 and switch S41 ..., S50 and electric capacity C15,
C16, C17, Cfb1, Cfb2 constitute input Commom-mode feedback circuit.
Further, in modulator structure module, switch S1 one end connection reference voltage Vref, the other end is linked to node
C；Switch S2 one end is linked to node C, and the other end is with being connected to the common mode of circuit or ground；Switch S4 is connected to node A together
Between mould ground, switch S3 is connected between node B and common mode ground；Electric capacity Cs1 is connected between node C and node A, electric capacity Cs2
It is connected between node C and node B, electric capacity Ch1 is connected between node A and operational amplifier A MP1 negative input end, electric capacity
Ch2 is connected between node B and operational amplifier A MP1 positive input terminal；Switch S5 is connected between node B and node N1, is opened
S6 is closed to be connected between node A and node N2；Switch S7 is connected between node N1 and operational amplifier A MP1 positive input terminal,
Switch S8 is connected between operational amplifier A MP1 negative input end and node N2；Integrating capacitor Cf1 is connected to operational amplifier
Between AMP1 positive input terminal and negative output terminal, Cf2 is connected between operational amplifier A MP1 negative input end and positive output end；
Switch S11 is connected between node F and node addp1, and switch S12 is connected between node E and addn1；Switch S9 is connected to
Between node addn1 and common mode ground, switch S10 is connected between node addp1 and common mode ground；Switch S13 is connected to section
Between point N3 and common mode ground, switch S14 is connected between node N4 and common mode ground；Switch S15 is connected to node N3 and put with computing
Between big device AMP2 positive input terminal, switch S16 is connected between node N4 and operational amplifier A MP2 negative input end；
Electric capacity C11 is connected across between operational amplifier A MP2 negative input end and positive output end, and C12 is connected across operational amplifier A MP2's
Between positive input output end and negative output terminal；Switch S17 be connected to operational amplifier A MP2 negative output terminals and node addn2 it
Between, switch S18 is connected between operational amplifier A MP2 positive output end and node addn2；Electric capacity C3 is connected to node addp2
Between node N6, C4 is connected between node addn2 tie points and node N5；Switch S19 is connected to node addn2 and common mode
Between ground, switch S20 is connected between addp2 tie points and common mode ground；Switch S21 is connected between node N5 and common mode ground,
Switch S22 is connected between node N6 and common mode ground；Switch S23 is connected to node N5 and operational amplifier A MP3 positive input terminal
Between, switch S24 is connected between node N6 and operational amplifier A MP3 negative input end；Electric capacity C13 is connected across operation amplifier
Device AMP3 negative input end and positive output end, C14 is connected across operational amplifier A MP3 positive input output end and negative output terminal；Open
The negative output terminal that S25 is connected to node N7 and operational amplifier A MP3 is closed, switch S26 is connected to operational amplifier A MP3 positive outputs
Between end and node N8；Switch S27 is connected between node N7 and common mode ground, switch S28 with being connected to node N8 and common mode it
Between；Electric capacity C6 is connected between node N7 and node N9, and electric capacity C5 is connected to out between node N8 and node N10；S29 is switched to connect
It is connected between node N9 and common mode ground, switch S30 is connected between node N10 and common mode ground；Electric capacity C7 is connected to node addp1
Between node N10, C8 is connected between addn1 and node N9；Electric capacity C9 is connected between node addp2 and node N10,
C10 is connected between addn2 and node N9.
Further, in capacitance compensation array module, switch S31 is connected between reference voltage Vref end and node N11；
S32 is switched with being connected to node N11 and common mode or between ground；Capacitance compensation array Cc1 be connected to node N11 and node A it
Between, Cc2 is connected between node N11 and node B.
Further, in D/A converting circuit module, switch S33 be connected to the end of reference voltage Vref 1 and node N12 it
Between, by output Y2 controls, switch S34 is connected between the end of reference voltage Vref 2 and node N12, by output Y1 controls；Switch
Between S37 connecting nodes N12 and node N14, switch S39 is connected between node N14 and common mode ground；Electric capacity Cb2 is connected to section
Between point N14 and node B；Switch S35 is connected between the end of reference voltage Vref 2 and node N13, by output Y2 controls；Switch
S36 is connected between the end of reference voltage Vref 1 and node N13, is controlled by output signal Y1；Switch S38 be connected to node N13 with
Between node N15, switch S40 is connected between node N15 and common mode ground；Electric capacity Cb1 is connected between node N15 and node A.
Further, in input Common-mode compensation circuitry module, S47 is switched with being connected to node N16 and common mode, electric capacity C15
It is connected between node N16 and node N19, electric capacity C16 is connected between node N16 and node N18, switch S48 is connected to section
Point N16 and operational amplifier A MP4 negative input end；Switch S49 concatenation operation amplifiers AMP4 negative input end and node N17
Between, switch S50 is connected between node N17 and operational amplifier A MP4 positive input terminal；Electric capacity C17 is connected to node N17
With operational amplifier A MP4 output end；Switch between S41 connecting nodes N20 and node N18, switch S42 is connected to node N19
Between node N20；Switch between S45 connecting nodes N18 and node F, switch S46 is connected between node N19 and node E；
Switch S43 is connected between node N20 and node N21, and switch S44 is connected between node N21 and common mode ground；Electric capacity Cfb1 connects
It is connected between node N21 and A, electric capacity Cfb2 is connected between node N21 and node B.
One or more technical schemes that the application is provided, have at least the following technical effects or advantages：
New integrated detection circuit in the application, is solved by the way that sensitive structure is combined with Sigma-Delta modulator
Certainly above-mentioned the problem of, the differential capacitance of sensitive structure is used as the sampling capacitance of Sigma-Delta modulator；The change of differential capacitance
Change and be directly changed into error signal in Sigma-Delta loops, thus be no longer needed for here using voltage as in conversion
It is situated between；The structure also has another benefit, and front end amplifier is only a simple integrated transporting discharging, without being to need to consume greatly
The C/V of power consumption is measured, therefore, the power consumption of system is effectively reduced；Simultaneously problem, the application are obtained in order to solve front end input common mode
It it is also proposed an appropriate input common mode compensation feedback circuit；So, solve existing accelerometer capacitive detection circuit
In the presence of easily being influenceed by environment and oneself factor, and power consumption is higher, is not easy to the technical problem of processing, and then realizes circuit
It is reasonable in design, environment and the influence of itself are not easily susceptible to, testing result is accurate, and the relatively low technique effect of power consumption.
Brief description of the drawings
Accompanying drawing described herein is used for providing further understanding the embodiment of the present invention, constitutes one of the application
Point, do not constitute the restriction to the embodiment of the present invention；
Fig. 1 is integrated three ranks electric charge Sigma Delta capacitive detection circuit connection diagrams；
Fig. 2 traditional Si gma Delta accelerometer capacitive detection circuit schematic diagrames；
Fig. 3 is digital accelerometer capacitive detection circuit application example schematic diagram；
Fig. 4 is the time diagram of Non-Overlapping Clock (non-overlapping clock) requirements.
Embodiment
The invention provides a kind of accelerometer capacitive detection circuit, existing accelerometer capacitive detection circuit is solved
In the presence of easily being influenceed by environment and oneself factor, power consumption is higher, realizes circuit design rationally, is not easily susceptible to environment and itself
Influence, testing result is accurate, and the relatively low technique effect of power consumption.
It is below in conjunction with the accompanying drawings and specific real in order to be more clearly understood that the above objects, features and advantages of the present invention
Mode is applied the present invention is further described in detail.It should be noted that in the case where not conflicting mutually, the application's
Feature in embodiment and embodiment can be mutually combined.
Many details are elaborated in the following description to facilitate a thorough understanding of the present invention, still, the present invention may be used also
Implemented with the other modes in the range of being different from being described herein using other, therefore, protection scope of the present invention is not by under
The limitation of specific embodiment disclosed in face.
Fig. 1 is refer to, this application provides the integrated accelerometer capacitive detection circuit of the present invention, by by accelerometer
Sensitive structure is combined with Sigma-Delta modulator, and the differential capacitance of sensitive structure is used as Sigma-Delta modulator
Sampling capacitance, its specific circuit connection is as shown in Figure 1.Fig. 1 can be divided into four modules, the Sigma- for the summation that feedovered using three ranks
The module of Delta modulator structures is 1.；Capacitance compensation array module is 2.；The digital-to-analogue that numeral output feeds back to first order integrator turns
Change circuit module 3.；Input Common-mode compensation circuitry module 4..Module 1. in include the equivalent capacity of accelerometer sensitive structure
【Cs1】【Cs2】, amplifier【AMP1】【AMP2】【AMP3】And comparator【CMP】And switch【S1】…【S30】, electric capacity【C1】…
【C14】, correlated-double-sampling electric capacity【Ch1】【Ch2】, first order integrator electric capacity【Cf1】【Cf2】, module 2. in comprising switch
【S31】【S32】And electric capacity【Cc1】【Cc2】, module 3. in comprising switch【S33】…【S40】And electric capacity【Cb1】【Cb2】, mould
Block 4. in include single-ended amplifier【AMP4】, switch【S41】…【S50】, electric capacity【C15】【C16】【Cfb1】【Cfb2】.Two-phase is non-heavy
Folded clock signal【φ1】【φ2】。
Amplifier【AMP1】With switch【S1】…【S8】, electric capacity【Cs1】【Cs2】【Ch1】【Ch2】【Cf1】【Cf2】Constitute first
Level switched-capacitor integrator；Amplifier【AMP2】With switch【S9】…【S16】, electric capacity【C1】【C2】【C11】【C12】Constitute the second level
Switched-capacitor integrator；Amplifier【AMP3】With switch【S17】…【S24】, electric capacity【C3】【C4】【C13】【C14】Constitute ground three-level
Switched-capacitor integrator；Switch【S25】…【S30】, electric capacity【C5】…【C10】Constitute summing circuit；Comparator【CMP】As one
Position quantizer；Switch【S31】【S32】With electric capacity【Cc1】【Cc2】Formation base capacitor compensating circuit；Switch【S33】…【S40】
With electric capacity【Cb1】【Cb2】Constitute the negative-feedback that modulator is output to first switch electric capacity；Amplifier【AMP4】With switch【S41】…
【S50】, electric capacity【C15】【C16】【C17】【Cfb1】【Cfb2】Constitute input Commom-mode feedback circuit.
Circuit module 1. in, switch【S1】One end connects reference voltage【Vref】, the other end is linked to node【C】.Switch
【S2】One end is linked to node【C】, one end is with being connected to the common mode of circuit or ground.Switch【S4】It is connected to node【A】Together
Between mould ground, switch【S3】It is connected to node【B】Between common mode ground.Electric capacity【Cs1】It is connected to node【C】With node【A】It
Between, electric capacity【Cs2】It is connected to node【C】With node【B】Between, electric capacity【Ch1】It is connected to node【A】And amplifier【AMP1】It is negative
Between input, electric capacity【Ch2】It is connected to node【B】With amplifier【AMP1】Positive input terminal between.Switch【S5】It is connected to section
Point【B】With node【N1】Between, switch【S6】It is connected to node【A】With node【N2】Between.Switch【S7】It is connected to node
【N1】With amplifier【AMP1】Positive input terminal between, switch【S8】It is connected to amplifier【AMP1】Negative input end and node【N2】It
Between.Integrating capacitor【Cf1】It is connected to amplifier【AMP1】Positive input terminal and negative output terminal between,【Cf2】It is connected to amplifier
【AMP1】Negative input end and positive output end between.Switch【S11】It is connected to node【F】With node【addp1】Between, switch
【S12】It is connected to node【E】With【addn1】Between.Switch【S9】It is connected to node【addn1】Between common mode ground, switch
【S10】It is connected to node【addp1】Between common mode ground.Switch【S13】It is connected to node【N3】Between common mode ground, open
Close【S14】It is connected to node【N4】Between common mode ground.Switch【S15】It is connected to node【N3】With amplifier【AMP2】Positive input
Between end, switch【S16】It is connected to node【N4】With amplifier【AMP2】Negative input end between.Electric capacity【C11】It is connected across
Amplifier【AMP2】Negative input end and positive output end between,【C12】It is connected across amplifier【AMP2】Positive input output end with it is negative defeated
Go out between end.Switch【S17】It is connected to amplifier【AMP2】Negative output terminal and node【addn2】Between, switch【S18】It is connected to fortune
Put【AMP2】Positive output end and node【addn2】Between.Electric capacity【C3】It is connected to node【addp2】With node【N6】Between,
【C4】It is connected to node【addn2】Tie point and node【N5】Between.Switch【S19】It is connected to node【addn2】With common mode
Between, switch【S20】It is connected to【addp2】Between tie point and common mode ground.Switch【S21】It is connected to node【N5】With common mode
Between, switch【S22】It is connected to node【N6】Between common mode ground.Switch【S23】It is connected to node【N5】With amplifier【AMP3】
Positive input terminal between, switch【S24】It is connected to node【N6】With amplifier【AMP3】Negative input end between.Electric capacity【C13】Across
It is connected on amplifier【AMP3】Negative input end and positive output end,【C14】Transboundary in amplifier【AMP3】Positive input output end with it is negative defeated
Go out end.Switch【S25】It is connected to node【N7】With amplifier【AMP3】Negative output terminal, switch【S26】It is connected to amplifier【AMP3】
Positive output end and node【N8】Between.Switch【S27】It is connected to node【N7】Between common mode ground, switch【S28】It is connected to section
Point【N8】Between common mode ground.Electric capacity【C6】It is connected to node【N7】With node【N9】Between, electric capacity【C5】It is connected to out node
【N8】With node【N10】Between.Switch【S29】It is connected to node【N9】Between common mode ground, switch【S30】It is connected to node
【N10】Between common mode ground.Electric capacity【C7】It is connected to node【addp1】With node【N10】Between,【C8】It is connected to【addn1】
With node【N9】Between.Electric capacity【C9】It is connected to node【addp2】With node【N10】Between,【C10】It is connected to【addn2】With
Node【N9】Between.
Circuit module 2. in, switch【S31】It is connected to reference voltage【Vref】With node【N11】Between.Switch【S32】Even
It is connected on node【N11】And common mode or ground between.Capacitance compensation array【Cc1】It is connected to node【N11】With node【A】It
Between,【Cc2】It is connected to node【N11】With node【B】Between.
Circuit module 3. in, switch【S33】It is connected to reference voltage【Vref1】With node【N12】Between, exported【Y2】
Control, switch【S34】It is connected to reference voltage【Vref2】With node【N12】Between, exported【Y1】Control.Switch【S37】Even
Connect node【N12】With node【N14】Between, switch【S39】It is connected to node【N14】Between common mode ground.Electric capacity【Cb2】Connection
In node【N14】With node【B】Between.Switch【S35】It is connected to reference voltage【Vref2】With node【N13】Between, exported
【Y2】Control.Switch【S36】It is connected to reference voltage【Vref1】With node【N13】Between, by output signal【Y1】Control.Open
Close【S38】It is connected to node【N13】With node【N15】Between, switch【S40】It is connected to node【N15】Between common mode ground.
Electric capacity【Cb1】It is connected to node【N15】With node【A】Between.
Circuit module 4. in, switch【S47】It is connected to node【N16】With common mode, electric capacity【C15】It is connected to node
【N16】With node【N19】Between, electric capacity【C16】It is connected to node【N16】With node【N18】Between, switch【S48】It is connected to
Node【N16】And amplifier【AMP4】Negative input end.Switch【S49】Connect amplifier【AMP4】Negative input end and node【N17】
Between, switch【S50】It is connected to node【N17】With amplifier【AMP4】Positive input terminal between.Electric capacity【C17】It is connected to node
【N17】With amplifier【AMP4】Output end.Switch【S41】Connecting node【N20】With node【N18】Between, switch【S42】Connection
In node【N19】With node【N20】Between.Switch【S45】Connecting node【N18】With node【F】Between, switch【S46】Connection
In node【N19】With node【E】Between.Switch【S43】It is connected to node【N20】With node【N21】Between, switch【S44】Even
It is connected on node【N21】Between common mode ground.Electric capacity【Cfb1】It is connected to node【N21】With【A】Between, electric capacity【Cfb2】It is connected to
Node【N21】With node【B】Between.
The digital accelerometer capacitive detection circuit of the present invention by outside, it is necessary to produce stable direct current supply voltage and clock
Signal, after detection processing of circuit, acceleration signal is converted directly into data serial signal output, in the numeral of rear class
Down-sampled and digital filtering is completed in circuit, and digital compensation can be done to result, in the processing Jing Guo digital circuit and benefit
After repaying, back can be directly to single-chip microcomputer or host computer, be read data signal by them.It is used as the number of their acceleration signals
According to source.Circuit block diagram as shown in Figure 3, the sequential relationship of its two-phase non-overlapp-ing clock used is as shown in Figure 4.
Technical scheme in above-mentioned the embodiment of the present application, at least has the following technical effect that or advantage：
New integrated detection circuit in the application, is solved by the way that sensitive structure is combined with Sigma-Delta modulator
Certainly above-mentioned the problem of, the differential capacitance of sensitive structure is used as the sampling capacitance of Sigma-Delta modulator；The change of differential capacitance
Change and be directly changed into error signal in Sigma-Delta loops, thus be no longer needed for here using voltage as in conversion
It is situated between；The structure also has another benefit, and front end amplifier is only a simple integrated transporting discharging, without being to need to consume greatly
The C/V of power consumption is measured, therefore, the power consumption of system is effectively reduced；Simultaneously problem, the application are obtained in order to solve front end input common mode
It it is also proposed an appropriate input common mode compensation feedback circuit；So, solve existing accelerometer capacitive detection circuit
In the presence of easily being influenceed by environment and oneself factor, and power consumption is higher, is not easy to the technical problem of processing, and then realizes circuit
It is reasonable in design, environment and the influence of itself are not easily susceptible to, testing result is accurate, and the relatively low technique effect of power consumption.
, but those skilled in the art once know basic creation although preferred embodiments of the present invention have been described
Property concept, then can make other change and modification to these embodiments.So, appended claims are intended to be construed to include excellent
Select embodiment and fall into having altered and changing for the scope of the invention.
Obviously, those skilled in the art can carry out the essence of various changes and modification without departing from the present invention to the present invention
God and scope.So, if these modifications and variations of the present invention belong to the scope of the claims in the present invention and its equivalent technologies
Within, then the present invention is also intended to comprising including these changes and modification.
Claims (10)
1. a kind of accelerometer capacitive detection circuit, it is characterised in that the circuit includes：
Modulator structure module, capacitance compensation array module, D/A converting circuit module, input Common-mode compensation circuitry module；Its
In, modulator structure module is used to the change of accelerometer electric capacity being converted to numeral output, and capacitance compensation array module is used for
The imbalance of basic electric capacity and the error in accelerometer sensitive structure are offset, D/A converting circuit module is used to realize that one-bit digital is defeated
Go out the feedback to first order switched-capacitor integrator, input Common-mode compensation circuitry is used to eliminate first order switched-capacitor integrator
Common mode input deviation；Capacitance compensation array is connected to the front end of modulator block first order switched-capacitor integrator, digital-to-analogue
Change-over circuit is connected to first order switched-capacitor integrator, input Common-mode compensation circuitry sampling under the control that one-bit digital is exported
The output of first order switched-capacitor integrator, tries to achieve the input elimination that first order switched-capacitor integrator is fed back to after common-mode voltage
Its common mode input deviation.
2. accelerometer capacitive detection circuit according to claim 1, it is characterised in that modulator structure module includes：
Equivalent capacity Cs1, Cs2 of accelerometer sensitive structure, operational amplifier A MP1, AMP2, AMP3, comparator CMP, switch
S1 ..., S30, electric capacity C1 ..., C14, correlated-double-sampling electric capacity Ch1, Ch2, the first order integrator electric capacity Cf1, Cf2.
3. accelerometer capacitive detection circuit according to claim 1, it is characterised in that capacitance compensation array module bag
Include：Switch S31, S32 and electric capacity Cc1, Cc2.
4. accelerometer capacitive detection circuit according to claim 1, it is characterised in that D/A converting circuit module bag
Include：Switch S33 ..., S40 and electric capacity Cb1, Cb2.
5. accelerometer capacitive detection circuit according to claim 1, it is characterised in that input Common-mode compensation circuitry module
Including：Single end operational amplifier AMP4, switch S41 ..., S50, electric capacity C15, C16, Cfb1, Cfb2.
6. accelerometer capacitive detection circuit according to claim 1, it is characterised in that operational amplifier A MP1 and switch
S1 ..., S8 and electric capacity Cs1, Cs2, Ch1, Ch2, Cf1, Cf2 constitute first order switched-capacitor integrator；Operational amplifier A MP2
With switch S9 ..., S16 and electric capacity C1, C2, C11, C12 constitute second level switched-capacitor integrator；Operational amplifier A MP3 is with opening
Pass S17 ... S24 and electric capacity C3, C4, C13, C14 constitute third level switched-capacitor integrator；Switch S25 ..., S30 and electric capacity
C5 ..., C10 constitute summing circuit；Comparator CMP is used as a quantizer；Switch S31, S32 and electric capacity Cc1, Cc2 constitute base
Plinth capacitor compensating circuit；Switch S33 ..., S40 and electric capacity Cb1, Cb2 constitute modulator and be output to the negative anti-of first switch electric capacity
Feedback；Operational amplifier A MP4 and switch S41 ..., that S50 and electric capacity C15, C16, C17, Cfb1, Cfb2 constitute input common mode is negative anti-
Current feed circuit.
7. accelerometer capacitive detection circuit according to claim 2, it is characterised in that in modulator structure module, open
S1 one end connection reference voltage Vref is closed, the other end is linked to node C；Switch S2 one end is linked to node C, and the other end is connected to
The common mode of circuit or ground；Switch S4 is connected between node A and common mode ground, switch S3 with being connected to node B and common mode it
Between；Electric capacity Cs1 is connected between node C and node A, and electric capacity Cs2 is connected between node C and node B, and electric capacity Ch1 is connected to
Between node A and operational amplifier A MP1 negative input end, electric capacity Ch2 is connected to the just defeated of node B and operational amplifier A MP1
Enter between end；Switch S5 is connected between node B and node N1, and switch S6 is connected between node A and node N2；S7 is switched to connect
Between the positive input terminal for being connected on node N1 and operational amplifier A MP1, switch S8 is connected to operational amplifier A MP1 negative input end
Between node N2；Integrating capacitor Cf1 is connected between operational amplifier A MP1 positive input terminal and negative output terminal, Cf2 connections
Between operational amplifier A MP1 negative input end and positive output end；Switch S11 is connected between node F and node addp1, is opened
S12 is closed to be connected between node E and addn1；Switch S9 is connected between node addn1 and common mode ground, and switch S10 is connected respectively
Between node addp1 and common mode ground；Switch S13 be connected between node N3 and common mode ground, switch S14 be connected to node N4 with
Between common mode ground；Switch S15 is connected between node N3 and operational amplifier A MP2 positive input terminal, and switch S16 is connected respectively
Between node N4 and operational amplifier A MP2 negative input end；Electric capacity C11 is connected across operational amplifier A MP2 negative input end
Between positive output end, C12 is connected across between operational amplifier A MP2 positive input output end and negative output terminal；S17 is switched to connect
It is connected between operational amplifier A MP2 negative output terminals and node addn2, switch S18 is connected to operational amplifier A MP2 positive output
Between end and node addn2；Electric capacity C3 is connected between node addp2 and node N6, C4 be connected to node addn2 tie points with
Between node N5；Switch S19 is connected between node addn2 and common mode ground, and switch S20 is connected to addp2 tie points and common mode
Between ground；Switch S21 is connected between node N5 and common mode ground, and switch S22 is connected between node N6 and common mode ground；Switch
S23 is connected between node N5 and operational amplifier A MP3 positive input terminal, and switch S24 is connected to node N6 and operational amplifier
Between AMP3 negative input end；Electric capacity C13 is connected across operational amplifier A MP3 negative input end and positive output end, and C14 is connected across
Operational amplifier A MP3 positive input output end and negative output terminal；Switch S25 is connected to node N7 and operational amplifier A MP3's
Negative output terminal, switch S26 is connected between operational amplifier A MP3 positive output ends and node N8；Switch S27 is connected to node N7
Between common mode ground, switch S28 is connected between node N8 and common mode ground；Electric capacity C6 is connected between node N7 and node N9,
Electric capacity C5 is connected to out between node N8 and node N10；Switch S29 is connected between node N9 and common mode ground, switchs S30 connections
Between node N10 and common mode ground；Electric capacity C7 is connected between node addp1 and node N10, and C8 is connected to addn1 and node
Between N9；Electric capacity C9 is connected between node addp2 and node N10, and C10 is connected between addn2 and node N9.
8. accelerometer capacitive detection circuit according to claim 3, it is characterised in that in capacitance compensation array module,
Switch S31 is connected between reference voltage Vref end and node N11；Switch S32 with being connected to node N11 and common mode or ground it
Between；Capacitance compensation array Cc1 is connected between node N11 and node A, and Cc2 is connected between node N11 and node B.
9. accelerometer capacitive detection circuit according to claim 4, it is characterised in that in D/A converting circuit module,
Switch S33 is connected between the end of reference voltage Vref 1 and node N12, and by output Y2 controls, switch S34 is connected to reference voltage
Between Vref2 ends and node N12, by output Y1 controls；Switch between S37 connecting nodes N12 and node N14, switch S39 connections
Between node N14 and common mode ground；Electric capacity Cb2 is connected between node N14 and node B；Switch S35 is connected to reference voltage
Between Vref2 ends and node N13, by output Y2 controls；Switch S36 is connected between the end of reference voltage Vref 1 and node N13,
By output signal Y1 controls；Switch S38 is connected between node N13 and node N15, and switch S40 is connected to node N15 together
Between mould ground；Electric capacity Cb1 is connected between node N15 and node A.
10. accelerometer capacitive detection circuit according to claim 5, it is characterised in that input Common-mode compensation circuitry mould
In block, with being connected to node N16 and common mode, electric capacity C15 is connected between node N16 and node N19 switch S47, and electric capacity C16 connects
It is connected between node N16 and node N18, switch S48 is connected to node N16 and operational amplifier A MP4 negative input end；Switch
Between S49 concatenation operation amplifiers AMP4 negative input end and node N17, switch S50 is connected to node N17 and operational amplifier
Between AMP4 positive input terminal；Electric capacity C17 is connected to node N17 and operational amplifier A MP4 output end；Switch S41 connections section
Between point N20 and node N18, switch S42 is connected between node N19 and node N20；Switch S45 connecting nodes N18 and node
Between F, switch S46 is connected between node N19 and node E；Switch S43 is connected between node N20 and node N21, is switched
S44 is connected between node N21 and common mode ground；Electric capacity Cfb1 is connected between node N21 and A, and electric capacity Cfb2 is connected to node
Between N21 and node B.
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| CN201710581214.6A CN107192850B (en) | 2017-07-17 | 2017-07-17 | Accelerometer capacitance detection circuit |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108233933A (en) * | 2018-02-02 | 2018-06-29 | 中国科学院微电子研究所 | Fully differential CMOS switched-capacitor integrator |
| CN108362910A (en) * | 2018-02-10 | 2018-08-03 | 中国工程物理研究院电子工程研究所 | A kind of open loop micro-acceleration gauge |
| WO2019183922A1 (en) * | 2018-03-30 | 2019-10-03 | 深圳市为通博科技有限责任公司 | Capacitive detection circuit, touch detection apparatus, and terminal device |
| CN114487615A (en) * | 2022-04-06 | 2022-05-13 | 基合半导体（宁波）有限公司 | Capacitance measuring circuit and capacitance measuring method |
| RU2809588C1 (en) * | 2023-08-29 | 2023-12-13 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Тульский государственный университет" (ТулГУ) | Device for measuring accelerations |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6445331B1 (en) * | 2001-08-14 | 2002-09-03 | National Semiconductor Corporation | Apparatus and method for common-mode regulation in a switched capacitor circuit |
| US6473019B1 (en) * | 2001-06-21 | 2002-10-29 | Nokia Corporation | Low capacitance, low kickback noise input stage of a multi-level quantizer with dithering and multi-threshold generation for a multi-bit sigma-delta modulator |
| US20020175692A1 (en) * | 2001-02-21 | 2002-11-28 | Stmicroelectronics S.R.L. | Method and circuit for detecting movements through micro-electric-mechanical sensors, compensating parasitic capacitances and spurious movements |
| CN102072737A (en) * | 2009-11-25 | 2011-05-25 | 中国科学院电子学研究所 | High accuracy capacitive readout circuit with temperature compensation |
| CN102624397A (en) * | 2012-03-22 | 2012-08-01 | 哈尔滨工程大学 | High-linearity fully differential digital micro-accelerometer interface circuit system |
| US20130049809A1 (en) * | 2011-08-22 | 2013-02-28 | Chia-Tai Wu | Micro electro-mechanical system circuit capable of compensating capacitance variation and method thereof |
| CN103178828A (en) * | 2013-03-16 | 2013-06-26 | 哈尔滨工业大学 | High-order sigma-delta closed-loop accelerometer interface circuit capable of self-checking harmonic distortion |
| CN104049109A (en) * | 2014-07-07 | 2014-09-17 | 湘潭大学 | Servo reading circuit of MEMS acceleration sensor |
| CN104363020A (en) * | 2014-09-18 | 2015-02-18 | 电子科技大学 | Pipeline ADC (analog to digital converter) and error calibration method thereof |
| CN104639168A (en) * | 2015-02-15 | 2015-05-20 | 芯原微电子(上海)有限公司 | Sigma-Delta type analog-to-digital converter analog front end circuit |
| US20150145589A1 (en) * | 2013-11-22 | 2015-05-28 | Murata Manufacturing Co., Ltd. | Capacitance processing circuit and a mems device |
| CN105116232A (en) * | 2015-08-13 | 2015-12-02 | 上海矽睿科技有限公司 | Capacitance detection circuit and capacitance sensing circuit |
| CN106169934A (en) * | 2016-03-15 | 2016-11-30 | 菅端端 | A kind of for the temperature-compensation circuit of pressure transducer and the quantization method of analog result thereof and temperature sensor method of work |
| US20170047938A1 (en) * | 2015-08-14 | 2017-02-16 | Cirrus Logic International Semiconductor Ltd. | Dual processing paths for differential mode and common mode signals for an adaptable analog-to-digital converter (adc) topology |
-
2017
- 2017-07-17 CN CN201710581214.6A patent/CN107192850B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020175692A1 (en) * | 2001-02-21 | 2002-11-28 | Stmicroelectronics S.R.L. | Method and circuit for detecting movements through micro-electric-mechanical sensors, compensating parasitic capacitances and spurious movements |
| US6473019B1 (en) * | 2001-06-21 | 2002-10-29 | Nokia Corporation | Low capacitance, low kickback noise input stage of a multi-level quantizer with dithering and multi-threshold generation for a multi-bit sigma-delta modulator |
| US6445331B1 (en) * | 2001-08-14 | 2002-09-03 | National Semiconductor Corporation | Apparatus and method for common-mode regulation in a switched capacitor circuit |
| CN102072737A (en) * | 2009-11-25 | 2011-05-25 | 中国科学院电子学研究所 | High accuracy capacitive readout circuit with temperature compensation |
| US20130049809A1 (en) * | 2011-08-22 | 2013-02-28 | Chia-Tai Wu | Micro electro-mechanical system circuit capable of compensating capacitance variation and method thereof |
| CN102624397A (en) * | 2012-03-22 | 2012-08-01 | 哈尔滨工程大学 | High-linearity fully differential digital micro-accelerometer interface circuit system |
| CN103178828A (en) * | 2013-03-16 | 2013-06-26 | 哈尔滨工业大学 | High-order sigma-delta closed-loop accelerometer interface circuit capable of self-checking harmonic distortion |
| US20150145589A1 (en) * | 2013-11-22 | 2015-05-28 | Murata Manufacturing Co., Ltd. | Capacitance processing circuit and a mems device |
| CN104049109A (en) * | 2014-07-07 | 2014-09-17 | 湘潭大学 | Servo reading circuit of MEMS acceleration sensor |
| CN104363020A (en) * | 2014-09-18 | 2015-02-18 | 电子科技大学 | Pipeline ADC (analog to digital converter) and error calibration method thereof |
| CN104639168A (en) * | 2015-02-15 | 2015-05-20 | 芯原微电子(上海)有限公司 | Sigma-Delta type analog-to-digital converter analog front end circuit |
| CN105116232A (en) * | 2015-08-13 | 2015-12-02 | 上海矽睿科技有限公司 | Capacitance detection circuit and capacitance sensing circuit |
| US20170047938A1 (en) * | 2015-08-14 | 2017-02-16 | Cirrus Logic International Semiconductor Ltd. | Dual processing paths for differential mode and common mode signals for an adaptable analog-to-digital converter (adc) topology |
| CN106169934A (en) * | 2016-03-15 | 2016-11-30 | 菅端端 | A kind of for the temperature-compensation circuit of pressure transducer and the quantization method of analog result thereof and temperature sensor method of work |
Non-Patent Citations (1)
| Title |
|---|
| 李宗伟 等: "新型电容式MEMS加速度计数字接口电路设计", 《电子学报》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108233933A (en) * | 2018-02-02 | 2018-06-29 | 中国科学院微电子研究所 | Fully differential CMOS switched-capacitor integrator |
| CN108362910A (en) * | 2018-02-10 | 2018-08-03 | 中国工程物理研究院电子工程研究所 | A kind of open loop micro-acceleration gauge |
| CN108362910B (en) * | 2018-02-10 | 2020-02-07 | 中国工程物理研究院电子工程研究所 | Open-loop micro-accelerometer |
| WO2019183922A1 (en) * | 2018-03-30 | 2019-10-03 | 深圳市为通博科技有限责任公司 | Capacitive detection circuit, touch detection apparatus, and terminal device |
| US10698550B2 (en) | 2018-03-30 | 2020-06-30 | Shenzhen Weitongbo Technology Co., Ltd. | Capacitance detection circuit, touch detection device and terminal device |
| CN114487615A (en) * | 2022-04-06 | 2022-05-13 | 基合半导体（宁波）有限公司 | Capacitance measuring circuit and capacitance measuring method |
| CN114487615B (en) * | 2022-04-06 | 2022-08-30 | 基合半导体（宁波）有限公司 | Capacitance measuring circuit and capacitance measuring method |
| RU2809588C1 (en) * | 2023-08-29 | 2023-12-13 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Тульский государственный университет" (ТулГУ) | Device for measuring accelerations |
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