CN102087123B - Device and method for correcting capacitance sensing assembly - Google Patents
Device and method for correcting capacitance sensing assembly Download PDFInfo
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- CN102087123B CN102087123B CN 200910252935 CN200910252935A CN102087123B CN 102087123 B CN102087123 B CN 102087123B CN 200910252935 CN200910252935 CN 200910252935 CN 200910252935 A CN200910252935 A CN 200910252935A CN 102087123 B CN102087123 B CN 102087123B
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Abstract
The invention relates to a device and a method for correcting a capacitance sensing assembly. One end point of the device for correcting the capacitance sensing assembly is connected to the capacitance sensing assembly; an integrating circuit is connected to the capacitance sensing assembly and generates voltage output and latched output; a switching circuit converts a sensitivity correction parameter into two corresponding signal outputs, and converts a zero drift correction parameter into a corresponding simulation signal output; at least two first switch assemblies switch between two simulation signal outputs corresponding to two corresponding signal outputs and a fixed potential along with the magnitude of the frequency of a system; and at least one third switch assembly switches between the corresponding simulation signal output and the other fixed potential along with the magnitude of the frequency of the system. The device determines the switching between the corresponding signal outputs according to the magnitude of the latched output of the integrating circuit.
Description
Technical field
The present invention relates to electronic correction device and method, particularly correction (calibration) apparatus and method of a kind of capacitance type sensing assembly (capacitive sensing device).
Background technology
The electric capacity of capacitance type sensing assembly and capacitance variations sensitivity (sensitivity) all can be because of making and the imperfection of assembling, and itself and design load are had discrepancy, not only the electric capacity of each assembly has some discrepancy each other simultaneously, and the capacitance variations sensitivity (sensitivity) of each assembly also has some discrepancy each other.After this type of capacitance error and capacitance sensitivity error are amplified by reading circuit, on zero point drift (offset) and the capacitance sensitivity of reacting respectively at black box, therefore must revise zero point drift and capacitance sensitivity to specification by bearing calibration and circuit.
Alignment technique about the skew of assembly for example has U.S. Patent number US5, and 659,262, US7,155,979, US7,7461,553 documents such as grade.U.S. Patent number US5,659, the zero point drift correction of 262 disclosed micromechanical sensing components (Offset trimming for a micro-machined sensingdevice) but technology is the size that changes input signal by the power transformation group, come the up and down voltage of control capacitance plate, and then the process deviation of compensation assembly.
US7,155,979 and US7,7461,553 disclosed self-correction oversampling regulator generators and bearing calibration (self-calibrating oversampling electromechanical modulator andself-calibration method) are the numerical value of detecting equilibrium state, the skew of proofreading and correct assembly by the numerical value that changes corrective capacity again.
The skew of assembly and the alignment technique of sensitivity for example have U.S. Patent number US5,528,520.Bearing calibration with reference to correcting circuit and Figure 1B of Figure 1A, its alignment technique is V1, the V2 numerical code of utilizing two interdependent (dependent) of input, be label 101 and 102, and cooperate a mirror image circuit (CodeMirror) 120, produce four kinds of analog correction codes, zero point drift and the sensitivity of proofreading and correct assembly by following mark impulse density (FractionalPulse Density, FPD) equation again:
FPD＝B+G[(CA-CB)/(CA+CB)]，
Wherein, zero point drift B=(1/2)+[VCM-(V1+V2)/2]/(V1-V2), and
Sensitivity G=(VDD-VCM) (V1-V2).
Summary of the invention
The present invention discloses a kind of means for correcting and method of capacitance type sensing assembly.
In one embodiment, disclosed is a kind of means for correcting of capacitance type sensing assembly.This device comprises that a corrective capacity assembly, has the integrating circuit of latch function, at least two first switch modules and at least one the 3rd switch module.One end points of this corrective capacity assembly is connected to a capacitance sensing assembly.This integrating circuit connects so far the capacitance sensing assembly and produces a Voltage-output and and latchs output.This change-over circuit is converted to the signal output of two correspondences with a sensitivity correction parameter, and a drift correction parameter is converted to the analog signal output of a correspondence.The first switch module switches between the analog signal output of two correspondences and a set potential with the height of system frequency.The 3rd switch module switches between the analog signal output of correspondence and another set potential with the height of system frequency.This means for correcting decides the switching of the signal outlet chamber of this two correspondence also according to the height that latchs output of this integrating circuit.
In another embodiment, disclosed is a kind of bearing calibration of capacitance type sensing assembly.This bearing calibration comprises: the sensitivity correction parameter of an input is converted to the signal of two correspondences and exports the two ends of a pair of sense capacitance to, and the drift correction parameter of an input is converted to the analog signal output of a correspondence and exports a corrective capacity assembly to; Latch Output rusults by a plurality of switch modules and according to one of system frequency and an integrating circuit, carry out signal output, this corresponding analog signal output of this two correspondence, and the switching between two set potentials; The independent value of this sensitivity correction parameter and the value of this drift correction parameter adjusted makes the characteristic of a sensing component that is comprised of a pair of sense capacitance meet respectively a sensitivity specification and a zero point drift specification; And read this to the output of sense capacitance and the Voltage-output after producing a correction.
The means for correcting of capacitance type sensing assembly disclosed by the invention and method are except providing the independent of zero point drift and sensitivity to proofread and correct, and the design of corrective capacity assembly also can reduce the tolerance of zero point drift effectively.The means for correcting of capacitance type sensing assembly of the present disclosure also can have the function of selftest concurrently.
Description of drawings
Figure 1A and Figure 1B are embodiment synoptic diagram, and a kind of correcting circuit and method of skew and sensitivity of assembly is described;
Fig. 2 is an embodiment synoptic diagram of the means for correcting of capacitance type sensing assembly;
Fig. 3 is an embodiment synoptic diagram, and the syndeton of corrective capacity assembly and sense capacitance is described when operating under normal mode;
Fig. 4 is an embodiment synoptic diagram, and the syndeton of corrective capacity assembly and sense capacitance is described when operating under the selftest pattern;
Fig. 5 A is an embodiment synoptic diagram of change-over circuit;
Fig. 5 B is another embodiment synoptic diagram of change-over circuit;
Fig. 6 is an embodiment synoptic diagram of the current potential conversion of correction voltage;
Two independent correcting codes are used in Fig. 7 A to Fig. 7 D explanation, come the up and down voltage swing of two battery lead plates of control capacitance assembly by frequency and integrating circuit Output rusults;
Fig. 8 illustrates that the corrective capacity value of adjusting programmable capacitor can correct the slope of calibration curve;
Fig. 9 is an embodiment process flow diagram, and the bearing calibration of capacitance type sensing assembly is described;
Figure 10 is an embodiment process flow diagram, and the arbitrary correction parameter that changes separately zero point drift or sensitivity is described, with independent suppressed zero drift or sensitivity;
Figure 11 is an embodiment synoptic diagram, illustrates how to export one set potential/selftest voltage by switch, carry out normal mode/selftest pattern.
Wherein accompanying drawing identifies:
101,102 liang of interdependent numerical code 200 means for correctings 210 change-over circuits
222 sensitivity correction parameters, 230 first switch modules 250 the 3rd switch module
CJ corrective capacity 305a the first corrective capacity 308 fixed voltages
810,820,830 calibration curves
The 910 sensitivity correction parameters with an input are converted to the signal of two correspondences and export the two ends of a pair of sense capacitance to, and the drift correction parameter of an input is converted to the analog signal output of a correspondence and exports a corrective capacity to
920 latch Output rusults by a plurality of switch modules and according to one of system frequency and an integrating circuit, carry out signal output, this corresponding analog signal output of this two correspondence, and the switching between two set potentials
The 930 independent value of this sensitivity correction parameter and the values of this drift correction parameter adjusted make the characteristic of a sensing component that is comprised of a pair of sense capacitance meet respectively a sensitivity specification and a zero point drift specification
940 read this to the output of sense capacitance and the Voltage-output after producing a correction
1010 adjust the value of sensitivity correction parameter
Whether 1020 met this zero point drift specification
1025 adjust the value of drift correction parameter
Whether 1030 meet this zero point drift specification
1122,1124 switch modules
Embodiment
The detailed description and the claim that cooperate accompanying drawing, embodiment are after purpose of the present invention and advantage be specified in.
In an embodiment of the present invention, utilize two kinds independently the figure adjustment code be responsible for respectively the zero point drift of sensing component and the analog-driven control of Electric potentials of sensitivity, utilize the arbitrary correcting code that changes separately assembly zero point drift and sensitivity, finish zero point drift or the independent of sensitivity of sensing component and proofread and correct.The electric capacity of wherein proofreading and correct usefulness can be a programmable corrective capacity, to promote the correction accuracy of its zero point drift.
Fig. 2 be the capacitance type sensing assembly means for correcting an embodiment synoptic diagram as shown, consistent with disclosed some embodiment.Among the embodiment of Fig. 2, means for correcting 200 can comprise that a corrective capacity assembly 205, a change-over circuit (transformer) 210, have integrating circuit (integration circuit) 220, at least two first switch modules 230 and at least one the 3rd switch module 250 that latchs (Latch) function.One end points of corrective capacity assembly 205 is connected to a capacitance sensing assembly 260.Corrective capacity assembly 205 has at least one corrective capacity.
The drift correction parameter 211 that change-over circuit 210 will be inputted is converted to the analog signal output of a correspondence, such as analog correction voltage V3; And the sensitivity correction parameter 222 that will input is converted to the signal output of two correspondences, for example a pair of analog correction voltage (V1 and V2).Analog correction voltage V3 can export corrective capacity assembly 205 to by the 3rd switch module 250, and analog correction voltage V1 and V2 for example can export a pair of sense capacitance CA and CB end to by at least one second switch assembly 240 and at least two first switch modules 230, make it meet respectively a zero point drift specification and a sensitivity specification thereby adjust its characteristic.
That is to say, change-over circuit 210 is with the sensitivity correction parameter 211 and drift correction parameter 222 of input, be converted to correction voltage, for example analog correction voltage V1, V2 and V3, and export capacitive transducer end and corrective capacity end to by switch, make its zero point drift and sensitivity to specification thereby adjust its characteristic.
At least two first switch modules 230 and the height (High) and low (Low) of at least one the 3rd switch module 250 according to clock frequency (Clock) carry out analog correction voltage, for example V1, V2 and V3, switching.And means for correcting 200 can be according to the height that latchs output of integrating circuit 220, decide the switching of the signal outlet chamber of this two correspondence, for example, according to the Output rusults that latchs of integrating circuit 220, and by at least one second switch assembly 240, carry out the switching of the signal outlet chamber of two correspondences.That is to say, can utilize at least two the first switch modules 230 in conjunction with at least one second switch assembly 240 and at least one the 3rd switch module 250, and respectively by the height 220a that latchs output of frequency and integrating circuit 220, come the voltage swing of the power-on and power-off pole plate of control capacitance assembly.
Take Fig. 2 as example, two the first switch modules 230 switch between two corresponding simulating signals (V1 and V2) that change-over circuit 210 provides and a set potential VR with the height of system frequency.The 3rd switch module 250 switches between the simulating signal V3 of the correspondence that change-over circuit 210 provides and another set potential VCM with the height of system frequency.Two outputs of second switch assembly 240 are switched in two corresponding simulating signals (V1 and the V2) outlet chamber that change-over circuit 210 provides with the height 220a that latchs output of integrating circuit 220.The value of set potential VR is more than or equal to zero potential and less than or equal to power supply supply current potential, can be power supply supply current potential, zero potential or other set potential, the value of another set potential VCM is more than or equal to zero potential and less than or equal to power supply supply current potential, can be half or other set potential of power supply supply current potential.
Means for correcting 200 can comprise sense capacitance (sensing capacitance) 260, the three end points capacitance sensing assemblies that sense capacitance 260 can be comprised of sense capacitance CA and CB, wherein an end points is the common point of two sense capacitance CA and CB, and all the other two-end-points are to be respectively the other two-end-point of sense capacitance CA and CB.Sense capacitance CA and CB can be differential types, also can be by at least one variable capacitance, at least one fixed capacity, or aforementioned electric capacity combines.Wherein, node VCJ, VCA and VCB are respectively two voltages of corrective capacity assembly 205, sense capacitance CA and CB end.Corrective capacity assembly 205 can be programmable capacitor (programmablecapacitance) or fixed capacity or the combination of aforementioned two kinds of electric capacity.
Means for correcting 200 can in the lower running of a normal mode (normal mode), also can operate under a selftest pattern (self test mode).When operating under normal mode, the syndeton of corrective capacity assembly and sense capacitance is shown in the embodiment of Fig. 3, and node VCA is connected to sense capacitance CA, node VCB is connected to sense capacitance CB; And corrective capacity assembly 205 one be connected to node VCJ, and the other end is connected to a fixed voltage 308.Corrective capacity assembly 205 can have multiple implementation structure, for example, corrective capacity assembly 205 can comprise one first corrective capacity 305a and one second corrective capacity 305b, wherein, one of the first corrective capacity 305a is connected to node VCJ, and the other end is the common point of the first corrective capacity 305a and the second corrective capacity 305b and is connected to capacitance sensing assembly 260; The other end of the second corrective capacity 305b then is connected to this fixed voltage.Means for correcting 200 reads the numerical value of two sense capacitance CA and CB under this normal mode running.The first corrective capacity 305a and one second corrective capacity 305b can be programmable capacitor or be fixed capacity or the combination of aforementioned two kinds of electric capacity.
When under the selftest pattern, operating, the syndeton of corrective capacity assembly and sense capacitance is shown in the embodiment of Fig. 4, and node VCA is connected to the end that an end, node VCJ that sense capacitance CA, node VCB be connected to the second corrective capacity 305b are connected to the first corrective capacity 305a; One selftest voltage VST then is connected to sense capacitance CB.External voltage VST can change by electrostatic force the capacitance of differential capacitor CA and CB, to carry out selftest.
Shown in the embodiment of Fig. 5 A, change-over circuit (transformer) 2 10 can comprise a translation subassembly (decoder) 511 and a digital/analog converter (Digital-to-Analog Convertor, DAC) 512.Translation subassembly 511 is converted to two analog output voltages by digital/analog converter 512, i.e. V1 and V2 after sensitivity correction parameter 222 is decoded as first two symmetric parameter 511a and 511b.Digital/analog converter 512 comprises two symmetric parameter 511a and 511b and drift correction parameter 211 respectively with input parameter, is converted to analog output voltage, comprises V1, V2 and V3.
Shown in the embodiment of Fig. 5 B, at least one second switch assembly 240 also can place between the interior translation subassembly 511 of change-over circuit and the digital/analog converter 512, and according to integrating circuit 220 latch output 220a height, after switching between two symmetric parameter 511a and 511b, export again digital/analog converter 512 to.
Integrating circuit (integration circuit) 240 for example can be a kind of trigonometric integral converter (Sigma-Delta Modulator) that is made of an integrator (Integrator), a comparer (Comparator) and a latch (Latch).
Fig. 6 is an embodiment synoptic diagram of the current potential conversion of correction voltage, and is consistent with disclosed some embodiment.Wherein, VDG represents the voltage difference of V1, V2 and VCM, and VCM represents common mode voltage (common modevoltage), and GND represents ground plane.Figure can learn that the current potential transformational relation of VDG, VCM, V1, V2 is thus:
VDG＝(V1-V2)/2，VCM＝(V1+V2)/2；
That is V1=VCM+VDG, V2=VCM-VDG.
And the whole output voltage VO UT of means for correcting 200 can be write as following equation:
VOUT＝VDD×{1/2+(VJ/2VDG)×[CJ/(CA+CB)]
+(VCM/2VDG)×[(CA-CB)/(CA+CB)]?}。
Wherein, CJ is the corrective capacity of corrective capacity assembly 205, VJ=V3-VCM.
Can be learnt by upper formulation, can adjust zero point drift by the numerical value that changes VJ and CJ, i.e. { 1/2+ (VJ/2VDG) * [CJ/ (CA+CB)] }, the result, under the correction of two parameters can so that the precision of zero point drift significantly promote; And the numerical value that changes VDG can be adjusted sensitivity, i.e. { (VCM/2VDG) * [(CA-CB)/(CA+CB)] }, Output rusults.Because VDG and VJ are correction parameters independently, the arbitrary correction parameter that changes separately assembly zero point drift and sensitivity can be finished the independence correction of zero point drift or sensitivity.With respect to the mode of interdependent correction, this mode of independently proofreading and correct can improve the easiness in the correction.
Fig. 7 A to Fig. 7 D further specifies and uses two independent correcting code VDG and VJ, comes the up and down voltage swing of two battery lead plates of control capacitance assembly by frequency and integrating circuit Output rusults, and is consistent with disclosed some embodiment.The electric voltage frequency transition diagram that Fig. 7 A explanation VCA is ordered, Fig. 7 B and Fig. 7 C illustrate respectively the voltage transitions figure of VCB and VCJ, last Fig. 7 D then is the synoptic diagram that frequency is switched.
In the embodiment of Fig. 7 A to Fig. 7 C, at least two the first switch modules 230 can use the design symmetry such as Delta Sigma with at least one second switch assembly 240, latch by frequency and integrating circuit that Output rusults comes on the control capacitance assembly, the voltage swing of lower electrode plate.When latch cicuit (Latch) was output as logical zero (Low), second switch assembly 240 was kept originally, directly output V1, the V2 of change-over circuit 210 was sent to the switching of first group of switch working frequency; And when latching (Latch) circuit when being output as logical one (High), after 240 output V1, V2 with change-over circuit 210 of second switch assembly exchange, be sent to the switching of the first switch module 230 working frequencies.Thus, can utilize the switching between the different voltages to finish the zero point drift of capacitance component and the correction of sensitivity.
The embodiment of Fig. 7 A and Fig. 7 C illustrates respectively the Output rusults that latchs by frequency and integrating circuit, how to control the voltage swing of the upper and lower battery lead plate of a differential capacitance assembly.Among the embodiment of Fig. 7 A, electric pole plate is in latching Output rusults LATCH when equaling logical zero (or Low), use correction voltage V1=VCM+VDG, and in latching Output rusults LATCH when equaling logical one (or High), use correction voltage V2=VCM-VDG, and export sense capacitance CA to and bring in and carry out the independent of sensitivity and proofread and correct.Among the embodiment of Fig. 7 C, lower electrode plate uses correction voltage V2=VCM-VDG in latching Output rusults LATCH when equaling logical zero, and latchs Output rusults LATCH when equaling logical one, use correction voltage V1=VCM+VDG, and export sense capacitance CB to and bring in and carry out the independent of sensitivity and proofread and correct.
The drift correction parameter is used in Fig. 7 B explanation, and the output V3 of change-over circuit 210 behind the corrective capacity CJ via adjustment able to programme, exports the common point of sense capacitance by after the frequency control to, carries out the independent of zero point drift and proofreaies and correct.So means for correcting 200 of the present disclosure can use two independent correcting code VDG and VJ, change separately zero point drift and the sensitivity of sensing component.
Correction parameter, such as drift correction parameter 211, sensitivity correction parameter 222 or electric capacity correction parameter etc. can be stored in first in the storage device.
The adjustment of the corrective capacity CJ of corrective capacity assembly 205 can be corrected the slope of calibration curve, be CJ/ (CA+CB), so that circuit can reduce the tolerance of zero point drift effectively in the correction of zero point drift, shown in the embodiment of Fig. 8, illustrate that the corrective capacity value of adjusting programmable capacitor can correct the slope of calibration curve.Among the embodiment of Fig. 8, transverse axis representative simulation correcting potential VJ, unit is volt; Counting (count of latches) is latched in longitudinal axis representative, and a frequency is 500KHz.Calibration curve 810,820,830 is respectively that the ratio of CJ/ (CA+CB) is 0.5,1.0,1.5 o'clock transformation result.
Hold above-mentionedly, Fig. 9 is an embodiment process flow diagram, and the bearing calibration of capacitance type sensing assembly is described, and is consistent with disclosed some embodiment.With reference to the 7th figure, in the step 910, the sensitivity correction parameter of one input is converted to the signal of two correspondences and exports the two ends of a pair of sense capacitance to, and the drift correction parameter of an input is converted to the analog signal output of a correspondence and exports a corrective capacity to.In the step 920, latch Output rusults by a plurality of switch modules and according to one of system frequency and an integrating circuit, carry out signal output, this corresponding analog signal output of this two correspondence, and the switching between two set potentials.
In the step 930, the independent value of this sensitivity correction parameter and the value of this drift correction parameter adjusted makes the characteristic of a sensing component that is comprised of a pair of sense capacitance meet respectively a sensitivity specification and a zero point drift specification.In the step 940, read this to the output of sense capacitance and the Voltage-output after producing a correction.
In the step 920, these a plurality of switch modules have a second switch assembly, two first switch modules and one the 3rd switch module at least, and as previously mentioned, the second switch assembly switches in the signal outlet chamber of two correspondences according to the height that latchs output of integrating circuit; Two first switch modules are with the height of system frequency, switch between the two corresponding analog signal outputs of the signal of two correspondences and set potential VR; The 3rd switch module switches between this corresponding analog signal output and another set potential VCM with the height of system frequency.By these switch modules, can utilize such as Delta Sigma design symmetry mode, carry out the switching of this three analog correction signals output.
The embodiment flow process of Figure 10 further specifies characteristic how independently to adjust sensing component in the step 920, makes it meet respectively a zero point drift specification and a sensitivity specification, and is consistent with disclosed some embodiment.Shown in the embodiment of Figure 10, can utilize the independent value of adjusting sensitivity and drift correction parameter, until up to specification.
At first, adjust the value (step 1010) of sensitivity correction parameter and check whether meet this sensitivity specification (step 1015), namely continuing to judge whether to meet zero point drift specification (step 1020) until meet this sensitivity specification, is to finish this aligning step.Words that no after input drift correction parameter, can be utilized the value (step 1025) of adjusting the drift correction parameter, judge whether to meet this zero point drift specification (step 1030), until meet this zero point drift specification.
Look back the embodiment of Fig. 4, means for correcting of the present disclosure also can operate under a selftest pattern.Embodiment can comprise also that at least two assembly switches carry out this selftest pattern.Figure 11 illustrates how to export and set potential VR/ selftest voltage VST by switch, carry out normal mode/selftest pattern with an embodiment, and is consistent with disclosed some embodiment.
With reference to the embodiment of Figure 11, illustrate how to export one set potential/selftest voltage by switch, carry out normal mode/selftest pattern, means for correcting 200 can also comprise a switch module 1122 and another switch module 1124.When operating under normal mode, switch module 1122 will switch to set potential VR, and therefore the end points of the second corrective capacity 305b will be connected to this set potential VR; Switch module 1124 switches to the output of the first switch module 230 in addition, so sense capacitance CB end will be connected to VCB.When operating under the selftest pattern, switch module 1122 will switch to the output of the first switch module 230, and therefore the end points of the second corrective capacity 305b will be connected to VCB; These external switch 1124 assemblies will switch to selftest voltage VST, that is to say that sense capacitance CB end will be connected to selftest voltage VST, therefore just can utilize this selftest voltage VST to carry out the test of sensing component.
In sum, the means for correcting of capacitance type sensing assembly of the present disclosure and the embodiment of method, utilize independently figure adjustment parameter, and come the voltage of control capacitance formula assembly by frequency and integrating circuit Output rusults, and can make its correction voltage of corrective capacity assembly coupled system frequency shift, the electric charge that just can adjust thus whole sensing component reaches the effect of suppressed zero drift and sensitivity.Except providing the independent of zero point drift and sensitivity to proofread and correct, to be outside one's consideration significantly to reduce correction of complex, the tolerance that the design of corrective capacity assembly also can reduce zero point drift effectively reaches the requirement of pinpoint accuracy.The means for correcting of capacitance type sensing assembly of the present disclosure also can have the function of selftest concurrently.
The above only is embodiments of the invention, can not limit according to this scope of the invention process.The equivalence that all the present patent application claims are done changes and revises, and should still belong to the scope that patent of the present invention contains.
Claims (25)
1. the means for correcting of a capacitance type sensing assembly, wherein, this device comprises:
The corrective capacity assembly has at least one corrective capacity, and an end of this corrective capacity assembly is connected to a capacitance sensing assembly;
Integrating circuit with latch function is connected to this capacitance sensing assembly and produces Voltage-output and latch output;
Change-over circuit is converted to the signal output of two correspondences with the sensitivity correction parameter, and the drift correction parameter is converted to the analog signal output of correspondence;
At least two first switch modules switch between the two corresponding analog signal outputs of the signal output of this two correspondence and a set potential with the height of system frequency; And
At least one the 3rd switch module switches between this corresponding analog signal output and another set potential with the height of system frequency;
Wherein, this device also latchs the height of output according to this of this integrating circuit, decides the switching of the signal outlet chamber of this two correspondence.
2. means for correcting as claimed in claim 1, wherein, the value of this set potential is more than or equal to zero potential and less than or equal to power supply supply current potential.
3. means for correcting as claimed in claim 1, wherein, the value of this another set potential is more than or equal to zero potential and less than or equal to power supply supply current potential.
4. means for correcting as claimed in claim 1, wherein, this change-over circuit comprises at least:
Translation subassembly is decoded as two symmetric parameters with this sensitivity correction parameter; And
Digital/analog converter is converted to the analog signal output of two correspondences with this two symmetric parameter, and this drift correction parameter is converted to this corresponding analog signal output.
5. means for correcting as claimed in claim 1, wherein, this integrating circuit is a kind of trigonometric integral converter that is made of integrator, comparer and latch.
6. means for correcting as claimed in claim 1, wherein, this corrective capacity assembly is one of them or its combination that is selected from fixed capacity, variable capacitance and programmable capacitor.
7. means for correcting as claimed in claim 1, wherein, this device also comprises storage device, and this storage device stores the first numerical code and the second numerical code at least, this the first numerical code is the adjusted value of this sensitivity correction parameter, and this second numerical code is the adjusted value of this drift correction parameter.
8. means for correcting as claimed in claim 1, wherein, this device also comprises this capacitance sensing assembly, and the three end points capacitance sensing assemblies that this capacitance sensing assembly is comprised of the first sense capacitance and the second sense capacitance, wherein an end points is the common point of this first and second sense capacitance, and all the other two-end-points are two other end points of this first and second sense capacitance.
9. means for correcting as claimed in claim 8, wherein, this is whole differential electric capacity to sense capacitance.
10. means for correcting as claimed in claim 8, wherein, by at least one variable capacitance, at least one fixed capacity, or aforementioned electric capacity combines to sense capacitance for this.
11. means for correcting as claimed in claim 1, wherein, this device also comprises at least one second switch assembly, switches between the two corresponding analog signal outputs that the signal of this two correspondence is exported.
12. means for correcting as claimed in claim 10, wherein, this corrective capacity assembly comprises the first corrective capacity and the second corrective capacity, and when this device operates under the selftest pattern, the voltage of this first sense capacitance end is connected to this first sense capacitance, the voltage of this second sense capacitance end is connected to this second corrective capacity, and the voltage of this first corrective capacity end is connected to this first corrective capacity, and selftest voltage is connected to this second sense capacitance.
13. means for correcting as claimed in claim 10, wherein, this corrective capacity assembly comprises the first corrective capacity and the second corrective capacity, and when this device operates under normal mode, this means for correcting reads this first and second sense capacitance, and the voltage of this first sense capacitance end is connected to this first sense capacitance, the voltage of this second sense capacitance end is connected to this second sense capacitance, the voltage of this first corrective capacity end is connected to this first corrective capacity, and this second corrective capacity is connected to a fixed voltage.
14. means for correcting as claimed in claim 10, wherein, this end of this corrective capacity assembly is connected to the common point of this two sense capacitance.
15. means for correcting as claimed in claim 11, wherein, this at least one second switch assembly has two outputs at least, and is connected to respectively this at least two first switch module.
16. means for correcting as claimed in claim 10, wherein, this at least two first switch module has two outputs at least, is connected to respectively this other two-end-point of this two sense capacitance.
17. means for correcting as claimed in claim 1, wherein, this at least one the 3rd switch module has at least an output and is connected to the other end of this corrective capacity assembly.
18. means for correcting as claimed in claim 4, wherein, this change-over circuit also comprises at least one second switch assembly, between this translation subassembly and this digital/analog converter, this at least one second switch assembly latchs the height of output according to this of this integrating circuit, after switching between this two symmetric parameter, export again this digital/analog converter to.
19. means for correcting as claimed in claim 8, wherein, this corrective capacity assembly is adjusted electric capacity by the programmable capacitor correction parameter, to promote the degree of accuracy of zero point drift.
20. means for correcting as claimed in claim 12, wherein, the voltage of this second sense capacitance end exports this second sense capacitance end and this second corrective capacity end to by the switching of at least two extra switch assemblies, and utilize external voltage to change the capacitance of this first and second sense capacitance, to carry out the selftest of this means for correcting.
21. the bearing calibration of a capacitance type sensing assembly is characterised in that, the method comprises:
The sensitivity correction parameter of input is converted to the signal of two correspondences and exports the two ends of a pair of sense capacitance to, and the drift correction parameter of an input is converted to the analog signal output of a correspondence and exports the corrective capacity assembly to;
By a plurality of switch modules and according to the Output rusults that latchs of system frequency and integrating circuit, carry out signal output, this corresponding analog signal output of this two correspondence, and the switching between two set potentials;
The independent value of this sensitivity correction parameter and the value of this drift correction parameter adjusted makes the characteristic of the sensing component that is comprised of a pair of sense capacitance meet respectively sensitivity specification and zero point drift specification; And
Read this to the output of sense capacitance and the Voltage-output after producing correction.
22. bearing calibration as claimed in claim 21, wherein, this independently adjusts the value of this sensitivity correction parameter and the value of this drift correction parameter also comprises:
Adjust the value of this sensitivity correction parameter, judge whether to meet this sensitivity specification, until meet this sensitivity specification; And
After meeting this sensitivity specification, continue to judge whether to have met this zero point drift specification, not yet meet this zero point drift specification, continue to adjust the value of this drift correction parameter, until meet this zero point drift specification.
23. bearing calibration as claimed in claim 21, wherein, the value of this two set potential is set to more than or equal to zero potential and less than or equal to power supply supply current potential.
24. bearing calibration as claimed in claim 21, wherein, these a plurality of switch modules have a second switch assembly, two first switch modules and one the 3rd switch module at least, the wherein signal of this two correspondence output, this corresponding analog signal output, and the switching between two set potentials also comprises:
Latch the height of output according to this of this integrating circuit, this second switch assembly switches in the signal outlet chamber of this two correspondence;
With the height of system frequency, this two first switch module is in the two corresponding analog signal outputs of signal and wherein the switching between a set potential of this two set potential of this two correspondence;
With the height of system frequency, the 3rd switch module switches between another set potential of this corresponding analog signal output and this two set potential.
25. bearing calibration as claimed in claim 21, wherein, the method also comprises:
Adjust the electric capacity of this corrective capacity assembly by the programmable capacitor correction parameter, to promote the degree of accuracy of this zero point drift.
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| CN104158544B (en) * | 2014-08-12 | 2017-08-25 | 昆明理工大学 | A kind of symmetrical expression high-speed, high precision voltage-freq converting circuit and conversion method |
| CN105911502B (en) * | 2016-06-12 | 2019-02-22 | 江西飞尚科技有限公司 | A kind of inconsistent ameliorative way of integrating capacitor in magnetic flux Acquisition Instrument |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0716308A2 (en) * | 1994-12-08 | 1996-06-12 | Ford Motor Company Limited | Calibration circuit for capacitive sensors |
| CN1348541A (en) * | 1999-02-25 | 2002-05-08 | 红木微系统公司 | Apparatus and method for correcting sensor drift |
| CN1975344A (en) * | 2005-11-30 | 2007-06-06 | 株式会社电装 | Capacitive physical quantity sensor and method of diagnosing the same |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0716308A2 (en) * | 1994-12-08 | 1996-06-12 | Ford Motor Company Limited | Calibration circuit for capacitive sensors |
| CN1348541A (en) * | 1999-02-25 | 2002-05-08 | 红木微系统公司 | Apparatus and method for correcting sensor drift |
| CN1975344A (en) * | 2005-11-30 | 2007-06-06 | 株式会社电装 | Capacitive physical quantity sensor and method of diagnosing the same |
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