US20130314075A1 - Offset error compensation systems and methods in sensors - Google Patents
Offset error compensation systems and methods in sensors Download PDFInfo
- Publication number
- US20130314075A1 US20130314075A1 US13/477,847 US201213477847A US2013314075A1 US 20130314075 A1 US20130314075 A1 US 20130314075A1 US 201213477847 A US201213477847 A US 201213477847A US 2013314075 A1 US2013314075 A1 US 2013314075A1
- Authority
- US
- United States
- Prior art keywords
- sensor
- offset error
- offset
- phase
- output
- 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.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims description 13
- 238000012937 correction Methods 0.000 claims description 18
- 238000009987 spinning Methods 0.000 claims description 3
- 230000005355 Hall effect Effects 0.000 claims description 2
- 230000035945 sensitivity Effects 0.000 abstract description 8
- 238000010586 diagram Methods 0.000 description 4
- 238000010348 incorporation Methods 0.000 description 3
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- DANMCYXBYDFTNH-ZRDIBKRKSA-N C=C(/C=C1\C=CCC1)C1=CC=CC1 Chemical compound C=C(/C=C1\C=CCC1)C1=CC=CC1 DANMCYXBYDFTNH-ZRDIBKRKSA-N 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
- G01R33/06—Measuring direction or magnitude of magnetic fields or magnetic flux using galvano-magnetic devices
- G01R33/07—Hall effect devices
- G01R33/072—Constructional adaptation of the sensor to specific applications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D3/00—Indicating or recording apparatus with provision for the special purposes referred to in the subgroups
- G01D3/028—Indicating or recording apparatus with provision for the special purposes referred to in the subgroups mitigating undesired influences, e.g. temperature, pressure
- G01D3/036—Indicating or recording apparatus with provision for the special purposes referred to in the subgroups mitigating undesired influences, e.g. temperature, pressure on measuring arrangements themselves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/12—Measuring force or stress, in general by measuring variations in the magnetic properties of materials resulting from the application of stress
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
- G01R33/06—Measuring direction or magnitude of magnetic fields or magnetic flux using galvano-magnetic devices
- G01R33/07—Hall effect devices
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
- G01R33/06—Measuring direction or magnitude of magnetic fields or magnetic flux using galvano-magnetic devices
- G01R33/09—Magnetoresistive devices
- G01R33/091—Constructional adaptation of the sensor to specific applications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
- G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
- G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
- G01D5/145—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices influenced by the relative movement between the Hall device and magnetic fields
Definitions
- the invention relates generally to sensors and more particularly to compensating for offset errors in sensors.
- Sensors often are used as sensor bridges, for example with four identical sensor elements coupled in a Wheatstone bridge configuration.
- Bridge circuits are supplied by a voltage or current and provide a differential output voltage. Examples include stress sensors, magnetoresistive sensors, and Hall plates and vertical Hall devices, among others.
- Offest is the output signal in the absence of the physical quantity which the sensor should detect. For example, for Hall plates the offset is the output signal at zero applied magnetic field, and for stress sensors it is the output signal at zero mechanical stress.
- the origin of offset error typically is a slight mismatch between the sensor elements of the bridge. In other words, the “identical” sensor elements are not exactly identical. A typical mismatch is on the order of about 0.1% to about 1%, which means that although the four sensor elements have identical resistances they actually differ by about 0.1-1%.
- the residual offset typically is on the order of about 30 micro-Tesla for Hall plates and about 0.5-1 mT for vertical Hall devices.
- a method comprises operating a sensor in a first operating phase having a first sensor input quantity to obtain a first sensor output signal and a first sensor offset error; operating the sensor in a second operating phase having a second sensor input quantity to obtain a second sensor output signal and a second sensor offset error; and providing a total sensor output signal comprising the sum of the first and second sensor output signals adjusted by a offset correction factor related to the first and second sensor offset errors.
- a sensor comprises at least one sensor element configured to sense a characteristic and having an input and an output; and offset compensation circuitry coupled to the output and configured to cancel an offset error of the sensor by correcting an output signal of the at least one sensor by a correction factor related to an offset error of the sensor when operated in a first phase and an offset error of the sensor when operated in a second phase.
- FIG. 1 is a diagram of a stress sensor circuit according to an embodiment.
- FIG. 2 is a diagram of a Hall plate circuit according to an embodiment.
- FIG. 3 is a diagram of a vertical Hall circuit according to an embodiment.
- FIG. 4 is a diagram of an offset correction circuit according to an embodiment.
- Embodiments relate to reducing offset error in sensor systems.
- the sensitivity and offset of a sensor depend differently on some parameter, e.g. voltage, such that operating the sensor at two different values of the parameter can cancel the offset error.
- Embodiments can have applicability to stress sensors ( FIG. 1 ), Hall plates ( FIG. 2 ), vertical Hall devices ( FIG. 3 ), magnetoresistive sensors and others.
- the sensitivity S and offset Off of a sensor depend differently on certain parameters, such as the supply voltage.
- operating the sensor at a first supply voltage Usup1 and a second supply voltage Usup2 provides two different output signals Ua1 and Ua2 that each depend on two unknowns: the physical quantity Q to be measured by the sensor and the Offset Off.
- Embodiments typically will not be applicable to perfectly linear sensors, those for which both sensitivity and offset depend in the same way on the parameter, such voltage. In practice, however, sensors are rarely perfectly linear, and all semiconductor sensors are nonlinear due to junction field effects. Therefore, embodiments are generally and widely applicable.
- a first example embodiment relates to the stress sensor 100 of FIG. 1 , of which the individual resistors R n are diffused resistors in silicon and the resistors R n are aligned in two different directions, ⁇ and ⁇ + ⁇ .
- a 1V supply voltage is applied to bridge circuit 100 , and the output voltage Ua1 is measured.
- a 2V supply voltage is applied to bridge circuit 100 , and the output voltage again is measured.
- the 1V and 2V supply voltage values are merely exemplary for purposes of this example and can vary in embodiments.
- the sensitivity of bridge 100 with respect to mechanical stress is directly proportional to the supply voltage, yet the resistance and thus the offset voltage is not purely directly proportional to the supply voltage but contains some quadratic terms.
- the offset error of bridge 100 at 2V is more than twice the offset voltage at 1V.
- this factor is 2.1, which will vary in embodiments.
- the output voltage at the second voltage Ua2 is divided by the factor 2.1 and then the output voltage at the first supply Ua1 is subtracted from the result. This removes the offset error.
- Hall effect devices such as ordinary Hall plates 200 or vertical Hall devices 300 .
- the aforementioned spinning current technique is used, in which the Hall device has several contacts, some of which are used as supply terminals and others as sense terminals in a first clock phase, and in other clock phases the roles of supply and sense terminals are exchanged and the signs of voltage or current supplies inverted.
- the sensed signals are then added with proper signs.
- the sensor After adding all of the signals with proper signs, the sensor has a first output signal Ua1 with a first residual zero point offset Off1.
- the sensor system operates Hall device 200 or 300 at a different supply voltage or supply current, which provides a different magnetic sensitivity, a different second output signal Ua2 and a different second residual zero point error Off2. Finally the total output can be calculated:
- Another example embodiment relates to magnetoresistive sensor bridges, such as giant magnetoresistive (GMR) sensors.
- GMR giant magnetoresistive
- this embodiment instead of applying two different voltages, two different magnetic fields are applied. These fields are referred to as secondary fields to distinguish them from the primary field from an external source to be detected by the sensor.
- the sensor system has control over the secondary magnetic field but not the primary. In embodiments, therefore, an electromagnet, coil, wire or other source is arranged proximate the
- the GMR sensor bridge in order to generate the secondary magnetic field when the system injects some current through it.
- the secondary magnetic field can be orthogonal to the primary magnetic field, and the GMR can be constructed in such a way so as to respond mainly on the primary magnetic fields and only with much lower sensitivity to the secondary magnetic fields.
- the sensor system can apply a first secondary magnetic field (e.g. zero) to the GMRs and sample the output signal Ua1:
- a first secondary magnetic field e.g. zero
- bridges need not be used.
- the GMR embodiment for example, does not rely on any bridge property.
- Circuit 400 comprises at least one sensor 402 , such as any of the sensors discussed herein above.
- Sensor 402 is supplied by two supplies, U1 and U2, sequentially, via switches S1 and S2 and clocked by a master clock oscillator 404 in an embodiment.
- An output signal of sensor 402 can be amplified in embodiments by an analog-to-digital converter (not shown in FIG. 4 ) and fed to a shift register 406 synchronously with master clock 404 .
- n-th value in shift register 406 is delayed by n clock cycles and is multiplied by a suitable chosen constant k and added to the (n+1)-th value in shift register 406 .
- the result is sampled in a track and hold circuit 408 and is the offset compensated output.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Measuring Magnetic Variables (AREA)
- Hall/Mr Elements (AREA)
Abstract
Embodiments relate to reducing offset error in sensor systems. In embodiments, the sensitivity and offset of a sensor depend differently on some parameter, e.g. voltage, such that operating the sensor at two different values of the parameter can cancel the offset error. Embodiments can have applicability to stress sensors, Hall plates, vertical Hall devices, magnetoresistive sensors and others.
Description
- The invention relates generally to sensors and more particularly to compensating for offset errors in sensors.
- Sensors often are used as sensor bridges, for example with four identical sensor elements coupled in a Wheatstone bridge configuration. Bridge circuits are supplied by a voltage or current and provide a differential output voltage. Examples include stress sensors, magnetoresistive sensors, and Hall plates and vertical Hall devices, among others.
- A common problem with sensor bridges, however is offset error. Offest is the output signal in the absence of the physical quantity which the sensor should detect. For example, for Hall plates the offset is the output signal at zero applied magnetic field, and for stress sensors it is the output signal at zero mechanical stress. The origin of offset error typically is a slight mismatch between the sensor elements of the bridge. In other words, the “identical” sensor elements are not exactly identical. A typical mismatch is on the order of about 0.1% to about 1%, which means that although the four sensor elements have identical resistances they actually differ by about 0.1-1%.
- Conventional approaches include, for Hall sensors, using the spinning current principle which uses different sensor elements in multiple clock phases to cancel any offset and enhance magnetic field proportional terms in the signals. This technique can be extended to more than two clock phases by reversing supply polarities and using more than four sensor elements. This technique, however, still results in a small offset error, referred to as the residual offset. The residual offset typically is on the order of about 30 micro-Tesla for Hall plates and about 0.5-1 mT for vertical Hall devices.
- Therefore, there is a need for improved offset error compensation for sensors.
- Embodiments relate to offset error compensation in sensors. In an embodiment, a sensor configured to sense a physical characteristic comprises at least one sensor element having an output, wherein an output signal comprises an offset error in an absence of the physical characteristic; an input quantity other than the physical characteristic that affects the offset error, wherein in a first phase of operation of the sensor a first input quantity produces a first output signal having a first offset error, and wherein in a second phase of operation of the sensor a second input quantity different from the first input quantity produces a second output signal having a second offset error; and offset correction circuitry coupled to the output and configured to provide a sensor output signal comprising a sum of the first output signal and a product of the second output signal and a correction factor chosen to offset a difference between the first offset error and the second offset error.
- In an embodiment, a method comprises operating a sensor in a first operating phase having a first sensor input quantity to obtain a first sensor output signal and a first sensor offset error; operating the sensor in a second operating phase having a second sensor input quantity to obtain a second sensor output signal and a second sensor offset error; and providing a total sensor output signal comprising the sum of the first and second sensor output signals adjusted by a offset correction factor related to the first and second sensor offset errors.
- In an embodiment, a sensor comprises at least one sensor element configured to sense a characteristic and having an input and an output; and offset compensation circuitry coupled to the output and configured to cancel an offset error of the sensor by correcting an output signal of the at least one sensor by a correction factor related to an offset error of the sensor when operated in a first phase and an offset error of the sensor when operated in a second phase.
- The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:
-
FIG. 1 is a diagram of a stress sensor circuit according to an embodiment. -
FIG. 2 is a diagram of a Hall plate circuit according to an embodiment. -
FIG. 3 is a diagram of a vertical Hall circuit according to an embodiment. -
FIG. 4 is a diagram of an offset correction circuit according to an embodiment. - While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
- Embodiments relate to reducing offset error in sensor systems. In embodiments, the sensitivity and offset of a sensor depend differently on some parameter, e.g. voltage, such that operating the sensor at two different values of the parameter can cancel the offset error. Embodiments can have applicability to stress sensors (
FIG. 1 ), Hall plates (FIG. 2 ), vertical Hall devices (FIG. 3 ), magnetoresistive sensors and others. - The sensitivity S and offset Off of a sensor depend differently on certain parameters, such as the supply voltage. In embodiments, operating the sensor at a first supply voltage Usup1 and a second supply voltage Usup2 provides two different output signals Ua1 and Ua2 that each depend on two unknowns: the physical quantity Q to be measured by the sensor and the Offset Off. In other words:
-
Ua1=S1Q+Off1 -
Ua2=S2Q+Off2 - Some linear combination of the signals can be found which will cancel the offsets:
-
Ua1+kUa2=(S1+kS2)Q+(Off1+kOff1) - where k=−Off1/Off2. Thus, the offset, or zero point error, is removed:
-
Ua,total=Ua1+kUa2=(S1+kS2)Q - Embodiments typically will not be applicable to perfectly linear sensors, those for which both sensitivity and offset depend in the same way on the parameter, such voltage. In practice, however, sensors are rarely perfectly linear, and all semiconductor sensors are nonlinear due to junction field effects. Therefore, embodiments are generally and widely applicable.
- A first example embodiment relates to the
stress sensor 100 ofFIG. 1 , of which the individual resistors Rn are diffused resistors in silicon and the resistors Rn are aligned in two different directions, φ and φ+α. In an embodiment, a 1V supply voltage is applied tobridge circuit 100, and the output voltage Ua1 is measured. Then, a 2V supply voltage is applied tobridge circuit 100, and the output voltage again is measured. The 1V and 2V supply voltage values are merely exemplary for purposes of this example and can vary in embodiments. Typically the sensitivity ofbridge 100 with respect to mechanical stress is directly proportional to the supply voltage, yet the resistance and thus the offset voltage is not purely directly proportional to the supply voltage but contains some quadratic terms. Therefore, the offset error ofbridge 100 at 2V is more than twice the offset voltage at 1V. For this example discussion, it is assumed that this factor is 2.1, which will vary in embodiments. Next, the output voltage at the second voltage Ua2 is divided by the factor 2.1 and then the output voltage at the first supply Ua1 is subtracted from the result. This removes the offset error. Mathematically: -
Ua1(Usup=1V)=S(Usup=1V)*STRESS+Off(Usup=1V) -
Ua2(Usup=2V)=S(Usup=2V)*STRESS+Off(Usup=2V) - with
-
S(Usup=2V)=2*S(Usup=1V) - and
-
Off(Usup=2V)=2.1*Off(Usup=1V). - Then the following is determined:
-
Ua2(Usup=2V)/2.1−Ua1(Usup=1V) - which is identical to
-
(S(Usup=2V)/2.1−S(Usup=1V))*STRESS - because the terms
-
Off(Usup=2V)/2.1−Off(Usup=1V)=0. - Referring to
FIGS. 2 and 3 , other examples relate to Hall effect devices, such asordinary Hall plates 200 orvertical Hall devices 300. In embodiments, the aforementioned spinning current technique is used, in which the Hall device has several contacts, some of which are used as supply terminals and others as sense terminals in a first clock phase, and in other clock phases the roles of supply and sense terminals are exchanged and the signs of voltage or current supplies inverted. The sensed signals are then added with proper signs. After adding all of the signals with proper signs, the sensor has a first output signal Ua1 with a first residual zero point offset Off1. Next, the sensor system operatesHall device -
Ua_total=Ua1+k*Ua2 - where k=−Off1/Off2.
- Another example embodiment relates to magnetoresistive sensor bridges, such as giant magnetoresistive (GMR) sensors. In this embodiment, instead of applying two different voltages, two different magnetic fields are applied. These fields are referred to as secondary fields to distinguish them from the primary field from an external source to be detected by the sensor. The sensor system has control over the secondary magnetic field but not the primary. In embodiments, therefore, an electromagnet, coil, wire or other source is arranged proximate the
- GMR sensor bridge in order to generate the secondary magnetic field when the system injects some current through it. In particular, the secondary magnetic field can be orthogonal to the primary magnetic field, and the GMR can be constructed in such a way so as to respond mainly on the primary magnetic fields and only with much lower sensitivity to the secondary magnetic fields.
- In operation, the sensor system can apply a first secondary magnetic field (e.g. zero) to the GMRs and sample the output signal Ua1:
-
Ua1=S1*Bx+Off(By1) - where S1 is the magnetic sensitivity of the sensor bridge during this first operating phase, Bx is the primary magnetic field to be detected by the system and Off is the offset error of the bridge, which is assumed to be a function of the secondary magnetic field By1, where Bx and By1 are perpendicular to one another. Next, a second secondary magnetic field is applied to the GMRs, and the output signal Ua2 is sampled:
-
Ua2=S2*Bx+Off(By2) - Finally, the total output is determined:
-
Ua_total=Ua1+k*Ua2 - where k=−Off(By1)/Off(By2). Thus:
-
Ua_total=(S1+k*S2)*Bx - which no longer has offset error.
- While examples comprising bridge configurations have been given, bridges need not be used. The GMR embodiment, for example, does not rely on any bridge property.
- In view of the above-discussed embodiments, and referring to
FIG. 4 , an example offsetcorrection circuit 400 according to embodiments is depicted.Circuit 400 comprises at least onesensor 402, such as any of the sensors discussed herein above.Sensor 402 is supplied by two supplies, U1 and U2, sequentially, via switches S1 and S2 and clocked by amaster clock oscillator 404 in an embodiment. An output signal ofsensor 402 can be amplified in embodiments by an analog-to-digital converter (not shown inFIG. 4 ) and fed to ashift register 406 synchronously withmaster clock 404. The n-th value inshift register 406 is delayed by n clock cycles and is multiplied by a suitable chosen constant k and added to the (n+1)-th value inshift register 406. The result is sampled in a track and holdcircuit 408 and is the offset compensated output. - Various embodiments of systems, devices and methods have been described herein. These embodiments are given only by way of example and are not intended to limit the scope of the invention. It should be appreciated, moreover, that the various features of the embodiments that have been described may be combined in various ways to produce numerous additional embodiments. Moreover, while various materials, dimensions, shapes, configurations and locations, etc. have been described for use with disclosed embodiments, others besides those disclosed may be utilized without exceeding the scope of the invention.
- Persons of ordinary skill in the relevant arts will recognize that the invention may comprise fewer features than illustrated in any individual embodiment described above. The embodiments described herein are not meant to be an exhaustive presentation of the ways in which the various features of the invention may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, the invention may comprise a combination of different individual features selected from different individual embodiments, as understood by persons of ordinary skill in the art.
- Any incorporation by reference of documents above is limited such that no subject matter is incorporated that is contrary to the explicit disclosure herein. Any incorporation by reference of documents above is further limited such that no claims included in the documents are incorporated by reference herein. Any incorporation by reference of documents above is yet further limited such that any definitions provided in the documents are not incorporated by reference herein unless expressly included herein.
- For purposes of interpreting the claims for the present invention, it is expressly intended that the provisions of Section 112, sixth paragraph of 35 U.S.C. are not to be invoked unless the specific terms “means for” or “step for” are recited in a claim.
Claims (20)
1. A sensor configured to sense a physical characteristic comprising:
at least one sensor element having an output, wherein an output signal comprises an offset error in an absence of the physical characteristic;
an input quantity other than the physical characteristic that affects the offset error, wherein in a first phase of operation of the sensor a first input quantity produces a first output signal having a first offset error, and wherein in a second phase of operation of the sensor a second input quantity different from the first input quantity produces a second output signal having a second offset error; and
offset correction circuitry coupled to the output and configured to provide a sensor output signal comprising a sum of the first output signal and a product of the second output signal and a correction factor chosen to offset a difference between the first offset error and the second offset error.
2. The sensor of claim 1 , wherein the input quantity is selected from the group consisting of a voltage, a current or a bias magnetic field.
3. The sensor of claim 1 , wherein the at least one sensor is selected from the group consisting of a Hall-effect sensor, a vertical Hall sensor, a spinning current vertical Hall sensor, a magnetoresistive sensor, and a stress sensor.
4. The sensor of claim 1 , wherein the at least one sensor element comprises a plurality of sensor elements coupled in a sensor bridge.
5. The sensor of claim 1 , wherein the offset correction circuitry comprises a shift register coupled to the output, and wherein the first and second output signals are stored by the shift register.
6. The sensor of claim 1 , wherein the correction factor comprises −1*(the first offset error)/(the second offset error).
7. A method comprising:
operating a sensor in a first operating phase having a first sensor input quantity to obtain a first sensor output signal and a first sensor offset error;
operating the sensor in a second operating phase having a second sensor input quantity to obtain a second sensor output signal and a second sensor offset error; and
providing a total sensor output signal comprising the sum of the first and second sensor output signals adjusted by a offset correction factor related to the first and second sensor offset errors.
8. The method of claim 7 , further comprising determining the offset correction factor by dividing the first sensor offset error by the second sensor offset error and multiplying the result by −1.
9. The method of claim 7 , wherein providing a total output signal further comprises summing the first sensor output signal with a product of the offset correction factor and the second sensor output signal.
10. The method of claim 7 , wherein the offset correction factor is chosen to cancel an offset error of the sensor.
11. The method of claim 7 , wherein the first and second sensor input quantities are selected from the group consisting of a voltage, a current and a magnetic field.
12. The method of claim 7 , wherein the sensor has an offset error in the absence of a physical quantity to be sensed by the sensor.
13. The method of claim 12 , wherein the physical quantity comprises a magnetic field, a voltage, a current, or a temperature.
14. A sensor comprising:
at least one sensor element configured to sense a characteristic and having an input and an output; and
offset compensation circuitry coupled to the output and configured to cancel an offset error of the sensor by correcting an output signal of the at least one sensor by a correction factor related to an offset error of the sensor when operated in a first phase and an offset error of the sensor when operated in a second phase.
15. The sensor of claim 14 , wherein a signal at the input of the at least one sensor element is different in the first phase and the second phase.
16. The sensor of claim 15 , wherein a signal at the output of the at least one sensor element is different in the first phase and the second phase.
17. The sensor of claim 14 , wherein the correction factor comprises a result of dividing the offset error in the first phase by the offset error in the second phase and multiplying by −1.
18. The sensor of claim 14 , wherein the sensor comprises a magnetic field sensor, a stress sensor, or a current sensor.
19. The sensor of claim 14 , wherein a total output of the sensor comprises the sum of outputs of the sensor in the first and second phases adjusted by the correction factor.
20. The sensor of claim 19 , wherein the total output of the sensor comprises the sum of the output of the sensor in the first phase and a product of the output of the sensor in the second phase and the correction factor.
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/477,847 US20130314075A1 (en) | 2012-05-22 | 2012-05-22 | Offset error compensation systems and methods in sensors |
CN201310190623.5A CN103424128B (en) | 2012-05-22 | 2013-05-21 | Offset error compensation system and method in sensor |
DE102013105231.2A DE102013105231B4 (en) | 2012-05-22 | 2013-05-22 | SYSTEMS AND PROCEDURES FOR OFFSET ERROR COMPENSATION IN SENSORS |
US14/598,398 US9404990B2 (en) | 2012-05-22 | 2015-01-16 | Sensor offset error compensation systems and methods using a correction factor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/477,847 US20130314075A1 (en) | 2012-05-22 | 2012-05-22 | Offset error compensation systems and methods in sensors |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/598,398 Continuation US9404990B2 (en) | 2012-05-22 | 2015-01-16 | Sensor offset error compensation systems and methods using a correction factor |
Publications (1)
Publication Number | Publication Date |
---|---|
US20130314075A1 true US20130314075A1 (en) | 2013-11-28 |
Family
ID=49621105
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/477,847 Abandoned US20130314075A1 (en) | 2012-05-22 | 2012-05-22 | Offset error compensation systems and methods in sensors |
US14/598,398 Active US9404990B2 (en) | 2012-05-22 | 2015-01-16 | Sensor offset error compensation systems and methods using a correction factor |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/598,398 Active US9404990B2 (en) | 2012-05-22 | 2015-01-16 | Sensor offset error compensation systems and methods using a correction factor |
Country Status (3)
Country | Link |
---|---|
US (2) | US20130314075A1 (en) |
CN (1) | CN103424128B (en) |
DE (1) | DE102013105231B4 (en) |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9346441B2 (en) | 2010-09-24 | 2016-05-24 | Infineon Technologies Ag | Sensor self-diagnostics using multiple signal paths |
US9410820B2 (en) | 2012-07-02 | 2016-08-09 | Infineon Technologies Ag | Stress compensation systems and methods in differential sensors |
US9488700B2 (en) | 2013-09-12 | 2016-11-08 | Infineon Technologies Ag | Magnetic field sensors and systems with sensor circuit portions having different bias voltages and frequency ranges |
US9618589B2 (en) | 2013-10-18 | 2017-04-11 | Infineon Technologies Ag | First and second magneto-resistive sensors formed by first and second sections of a layer stack |
US20170261306A1 (en) * | 2016-03-09 | 2017-09-14 | Infineon Technologies Ag | Extension sensor and reduction of a drift of a bridge circuit caused by an extension |
US9874609B2 (en) | 2010-09-24 | 2018-01-23 | Infineon Technologies Ag | Sensor self-diagnostics using multiple signal paths |
US10145882B2 (en) | 2010-09-24 | 2018-12-04 | Infineon Technologies Ag | Sensor self-diagnostics using multiple signal paths |
US10481032B2 (en) | 2012-07-02 | 2019-11-19 | Infineon Technologies Ag | Stress compensation systems and methods in sensors |
US10884092B2 (en) * | 2016-06-13 | 2021-01-05 | Allegro Microsystems, Llc | Non-orthogonality compensation of a magnetic field sensor |
CN112986645A (en) * | 2021-01-27 | 2021-06-18 | 力高(山东)新能源技术有限公司 | Method for eliminating current error caused by Hall power supply voltage |
US11703314B2 (en) | 2020-05-29 | 2023-07-18 | Allegro Microsystems, Llc | Analog angle sensor with digital feedback loop |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106164624B (en) * | 2014-03-31 | 2017-11-21 | 日立汽车系统株式会社 | Measuring physical |
US9964418B2 (en) | 2015-09-11 | 2018-05-08 | Joral Llc | Inter-sensor communication system for absolute position sensing |
CN106556807B (en) * | 2016-11-18 | 2019-05-14 | 清华大学 | Magnetic resistance static characteristic optimization method based on internal bias field and sensing direction |
CN106680743B (en) * | 2016-11-18 | 2019-07-19 | 清华大学 | Magnetic resistance static characteristic optimization method based on internal bias field easy axis direction |
CN106556810B (en) * | 2016-11-18 | 2019-08-02 | 清华大学 | Magnetic resistance static characteristic optimization method based on internal bias field hard axis direction |
CN106556808B (en) * | 2016-11-18 | 2019-08-02 | 清华大学 | Magnetic resistance static characteristic optimization method based on sensing direction |
FR3060127B1 (en) * | 2016-12-13 | 2019-03-15 | Seb S.A. | METHOD FOR DYNAMICALLY COMPENSATING THE OFFSET ERROR OF AN ACQUISITION CHAIN COMPRISING A CURRENT SENSOR |
CN109709496B (en) * | 2017-10-26 | 2021-05-11 | 北京自动化控制设备研究所 | Quantum sensor closed-loop control system and phase error compensation control method |
EP3644080B1 (en) * | 2018-10-23 | 2022-08-03 | Melexis Bulgaria Ltd. | Sensor circuit with offset compensation |
CN109342984A (en) * | 2018-11-16 | 2019-02-15 | 南方电网科学研究院有限责任公司 | Temperature and humidity influence correction compensation system and method for magnetic resistance chip |
CN113203520B (en) * | 2021-05-27 | 2023-12-22 | 北京京城清达电子设备有限公司 | Pressure sensor debugging system and method |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030057941A1 (en) * | 2001-07-27 | 2003-03-27 | Collier-Hallman Steven James | Tachometer apparatus and method for motor velocity measurement |
US20080238410A1 (en) * | 2006-10-16 | 2008-10-02 | Ami Semiconductor Belgium Bvba | Auto-calibration of magnetic sensor |
US8749227B2 (en) * | 2006-06-21 | 2014-06-10 | Allegro Microsystems, Llc | Methods for an analog rotational sensor having signal inversion |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4037150A (en) | 1973-05-30 | 1977-07-19 | Sergei Glebovich Taranov | Method of and apparatus for eliminating the effect of non-equipotentiality voltage on the hall voltage |
US4833406A (en) * | 1986-04-17 | 1989-05-23 | Household Commercial Financial Services Inc. | Temperature compensated Hall-effect sensor apparatus |
US5477471A (en) | 1993-10-29 | 1995-12-19 | Motorola, Inc. | Method of compensating for power supply variation in a sensor output |
DE4431703C2 (en) * | 1994-09-06 | 1997-01-30 | Itt Ind Gmbh Deutsche | Magnetic field sensor with Hall element |
FR2737777B1 (en) * | 1995-08-11 | 1997-10-31 | Motorola Semiconducteurs | SENSOR MODULE |
DE19640695A1 (en) * | 1996-10-02 | 1998-04-09 | Bosch Gmbh Robert | Magnetoresistive sensor with temperature-stable zero point |
DE19852502A1 (en) * | 1998-11-13 | 2000-05-18 | Philips Corp Intellectual Pty | Method for the offset calibration of a magnetoresistive angle sensor |
EP1540748B9 (en) | 2002-09-10 | 2018-03-07 | Melexis Technologies NV | Magnetic field sensor comprising a hall element |
US8058866B2 (en) * | 2008-09-08 | 2011-11-15 | Infineon Technologies Ag | Off-center angle measurement system |
EP2495578B1 (en) * | 2011-03-04 | 2013-09-18 | Nxp B.V. | Magnetic sensors |
CN102313562B (en) * | 2011-07-28 | 2014-04-23 | 中国科学院西安光学精密机械研究所 | Method and circuit for compensating additional phase drift of Y-shaped waveguide |
DE102012216388A1 (en) | 2011-09-16 | 2013-03-21 | Infineon Technologies Ag | HALL SENSORS WITH RECORDING NODES WITH SIGNAL INSIGNIA |
US9279865B2 (en) * | 2012-05-09 | 2016-03-08 | Everspin Technologies, Inc. | Method and structure for testing and calibrating three axis magnetic field sensing devices |
US9410820B2 (en) | 2012-07-02 | 2016-08-09 | Infineon Technologies Ag | Stress compensation systems and methods in differential sensors |
US9018948B2 (en) | 2012-07-26 | 2015-04-28 | Infineon Technologies Ag | Hall sensors and sensing methods |
US9170307B2 (en) | 2012-09-26 | 2015-10-27 | Infineon Technologies Ag | Hall sensors and sensing methods |
-
2012
- 2012-05-22 US US13/477,847 patent/US20130314075A1/en not_active Abandoned
-
2013
- 2013-05-21 CN CN201310190623.5A patent/CN103424128B/en not_active Expired - Fee Related
- 2013-05-22 DE DE102013105231.2A patent/DE102013105231B4/en not_active Expired - Fee Related
-
2015
- 2015-01-16 US US14/598,398 patent/US9404990B2/en active Active
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030057941A1 (en) * | 2001-07-27 | 2003-03-27 | Collier-Hallman Steven James | Tachometer apparatus and method for motor velocity measurement |
US8749227B2 (en) * | 2006-06-21 | 2014-06-10 | Allegro Microsystems, Llc | Methods for an analog rotational sensor having signal inversion |
US20080238410A1 (en) * | 2006-10-16 | 2008-10-02 | Ami Semiconductor Belgium Bvba | Auto-calibration of magnetic sensor |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9346441B2 (en) | 2010-09-24 | 2016-05-24 | Infineon Technologies Ag | Sensor self-diagnostics using multiple signal paths |
US9874609B2 (en) | 2010-09-24 | 2018-01-23 | Infineon Technologies Ag | Sensor self-diagnostics using multiple signal paths |
US10145882B2 (en) | 2010-09-24 | 2018-12-04 | Infineon Technologies Ag | Sensor self-diagnostics using multiple signal paths |
US10514410B2 (en) | 2010-09-24 | 2019-12-24 | Infineon Technologies Ag | Sensor self-diagnostics using multiple signal paths |
US9410820B2 (en) | 2012-07-02 | 2016-08-09 | Infineon Technologies Ag | Stress compensation systems and methods in differential sensors |
US10481032B2 (en) | 2012-07-02 | 2019-11-19 | Infineon Technologies Ag | Stress compensation systems and methods in sensors |
US9488700B2 (en) | 2013-09-12 | 2016-11-08 | Infineon Technologies Ag | Magnetic field sensors and systems with sensor circuit portions having different bias voltages and frequency ranges |
US9618589B2 (en) | 2013-10-18 | 2017-04-11 | Infineon Technologies Ag | First and second magneto-resistive sensors formed by first and second sections of a layer stack |
US20170261306A1 (en) * | 2016-03-09 | 2017-09-14 | Infineon Technologies Ag | Extension sensor and reduction of a drift of a bridge circuit caused by an extension |
US10884092B2 (en) * | 2016-06-13 | 2021-01-05 | Allegro Microsystems, Llc | Non-orthogonality compensation of a magnetic field sensor |
US11703314B2 (en) | 2020-05-29 | 2023-07-18 | Allegro Microsystems, Llc | Analog angle sensor with digital feedback loop |
CN112986645A (en) * | 2021-01-27 | 2021-06-18 | 力高(山东)新能源技术有限公司 | Method for eliminating current error caused by Hall power supply voltage |
Also Published As
Publication number | Publication date |
---|---|
DE102013105231B4 (en) | 2021-12-23 |
US9404990B2 (en) | 2016-08-02 |
CN103424128A (en) | 2013-12-04 |
US20150160325A1 (en) | 2015-06-11 |
CN103424128B (en) | 2015-12-23 |
DE102013105231A1 (en) | 2013-12-12 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9404990B2 (en) | Sensor offset error compensation systems and methods using a correction factor | |
US10580289B2 (en) | Sensor integrated circuits and methods for safety critical applications | |
US11846687B2 (en) | Devices and methods for measuring a magnetic field gradient | |
US8269491B2 (en) | DC offset removal for a magnetic field sensor | |
EP3123188B1 (en) | Circuits and methods for self-calibrating or self-testing a magnetic field sensor using phase discrimination | |
US9024629B2 (en) | Hall sensors having forced sensing nodes | |
US10605874B2 (en) | Magnetic field sensor with magnetoresistance elements having varying sensitivity | |
US9410820B2 (en) | Stress compensation systems and methods in differential sensors | |
CN109307793A (en) | The correcting device and current sensor of deviation estimating device and method, Magnetic Sensor | |
CN113432517A (en) | Magnetic field gradient-based position sensor apparatus, method and system | |
US10481032B2 (en) | Stress compensation systems and methods in sensors | |
US11835601B2 (en) | Magnetoresistive magnetic field sensor bridge with compensated cross-axis effect | |
JP2016142652A (en) | Power sensor | |
US20200370932A1 (en) | Magnetic field sensor and magnetic field sensing method | |
Wang | Eliminating bridge offset voltage for AMR sensors | |
WO2007097268A1 (en) | Magnetic switch |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: REGENTS OF THE UNIVERSITY OF MINNESOTA, MINNESOTA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:YAMAMOTO, MASATO;MIURA, YOSHIAKI;REEL/FRAME:028162/0978 Effective date: 20120430 |
|
AS | Assignment |
Owner name: INFINEON TECHNOLOGIES AG, GERMANY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:AUSSERLECHNER, UDO;MOTZ, MARIO;REEL/FRAME:028333/0194 Effective date: 20120515 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO PAY ISSUE FEE |