Patent Application
20180372810
The present disclosure claims the priority benefit of China Patent Application No. 201710492932.6, filed on 26 Jun. 2017, the content of which is incorporated by reference in its entirety.
The present disclosure generally relates to techniques of magnetic sensor and, more particularly, to a magnetic sensing apparatus and self-calibration methods, current sensor and sensing apparatus using the same.
The performance of magnetic sensors changes with the environment and time. In current technology, the magnetic sensors often have self-calibration functions. Taking magnetorestance (MR) sensor as an example, the Set/Reset function of an MR sensor can be used to calibrate a zero signal of the sensor and self-detect current coils to calibrate the sensitivity thereof. However, during calibration, the output signals will be affected. In addition, during the Set/Rest process, the output magnetic field signal will change the accuracy of calibration of the zero signal.
Therefore, there is a need for a new solution to solve the aforementioned problem.
This section is for the purpose of summarizing some aspects of the present disclosure and to briefly introduce some preferred embodiments. Simplifications or omissions in this section as well as in the abstract or the title of this description may be made to avoid obscuring the purpose of this section, the abstract and the title. Such simplifications or omissions are not intended to limit the scope of the present disclosure.
An aspect of the present disclosure is to provide a magnetic sensing apparatus and self-calibration methods using two magnetic sensors to ensure that during calibration the magnetic sensor may provide effective output signal and also enhance calibration accuracy.
To perform the above purpose, an aspect of the present disclosure to solve the above issue is to provide a self-calibration method of magnetic sensing apparatus, wherein the magnetic sensing apparatus comprises a first magnetic sensor, a second magnetic sensor, and a signal processing circuit. The first magnetic sensor and the second magnetic sensor can form on a same substrate. A method involves a signal processing circuit of the apparatus performing measurement using at least one magnetic sensor of the apparatus in response to an external magnetic field, and performing calibration using other magnetic sensor of the apparatus in calibration.
In some embodiments, when the first magnetic sensor is used in calibration, the second magnetic sensor measures an external magnetic field; when the second magnetic sensor is used in calibration, the first magnetic sensor measures the external magnetic field. When the second magnetic sensor is used in calibration, the first magnetic sensor measures the external magnetic field, and then the second magnetic sensor conducts SET operation. Adding a self-detection current upon a self-detection coils of the second magnetic sensor to calibrate a sensitivity of the second magnetic sensor to S2, and then the output signal of the first magnetic sensor is VA=VA0+S2*H, wherein VA0 denotes a zero signal of the first magnetic sensor and H is the external magnetic field. The signal processing circuit is used to adjust the output signal of the second magnetic sensor to VA, and then the output signal of the second magnetic sensor is VB1=VA0+S2*H. The second magnetic sensor is used to conduct the SET operation, and then the output signal of the second magnetic sensor is VB2=VA0−S2*H, wherein VA0=(VB1+VB2)/2 and H=(VB1−VB2)/(2*S2), to obtain VA0 after calibration and also the value of the external magnetic field. The second magnetic sensor is used to conduct SET operation, wherein the first magnetic sensor is used in calibration and the second magnetic sensor is used to conduct the measurement of the external magnetic field, and then the first magnetic sensor conducts the SET operation. By adding a self-detection current upon self-detection coils to calibrate the sensitivity of the first magnetic sensor to S1, the output signal of the second magnetic sensor is VB=VB0+S1*H, wherein VB0 denotes a zero signal of the second magnetic sensor, and H denotes the external magnetic field. The signal processing circuit is used to adjust the output signal of the first magnetic sensor to VB, and then the output signal of the first magnetic sensor is VA1=VB0+S1*H. The first magnetic sensor is used to conduct SET operation, and then the output signal of the first magnetic sensor is VA2=VB0−S1*H, wherein VB0=(VA1+VA2)/2 and H=(VA1−VA2)/(2*S1), to obtain VB0 after calibration and also the value of the external magnetic field. The first magnetic sensor is then used to conduct SET operation.
In some embodiments, the first magnetic sensor is used to continue the measurement, and the second magnetic sensor is used in calibration. The first magnetic sensor is used to conduct the measurement of the external magnetic field, and the second magnetic sensor is used in calibration, and then the second magnetic sensor conducts the SET operation. Adding a self-detection current upon a self-detection coils of the second magnetic sensor to calibrate a sensitivity of the second magnetic sensor to S2, and then the output signal of the first magnetic sensor is VA=VA0+S2*H, wherein VA0 denotes a zero signal of the first magnetic sensor and H denotes the external magnetic field. A signal processing circuit is used to adjust the output signal of the second magnetic sensor to VA, and then the output signal of the second magnetic sensor is VB2=VA0−S2*H, wherein VA0=(VB1+VB2)/2 and H=(VB1−VB2)/(2*S2) to obtain VA0 after calibration and also the value of the external magnetic field. A second magnetic sensor is then used to conduct SET operation.
An aspect of the present disclosure is to provide a magnetic sensing apparatus comprising a first magnetic sensor, a second magnetic sensor, and a signal processing circuit, wherein the first magnetic sensor and the second magnetic sensor can be formed on a same substrate. A method involves a signal processing circuit of the apparatus performing measurement using at least one magnetic sensor of the apparatus in response to an external magnetic field, and performing calibration using other magnetic sensor of the apparatus in calibration.
In some embodiments, when a first magnetic sensor is used to conduct calibration, a second magnetic sensor is used to conduct the measurement of the external magnetic field; when the second magnetic sensor is used to conduct calibration, the first magnetic sensor is used to conduct the measurement of an external magnetic field. When the second magnetic sensor is used to conduct calibration, the first magnetic sensor is used to conduct the measurement of the external magnetic field, and then the second magnetic sensor conducts the SET operation. Adding a self-detection current upon a self-detection coils of the second magnetic sensor to calibrate a sensitivity of the second magnetic sensor to S2, and then the output signal of the first magnetic sensor is VA=VA0+S2*H, wherein VA0 denotes a zero signal of the first magnetic sensor and H denotes the external magnetic field. A signal processing circuit is used to adjust the output signal of the second magnetic sensor to VA, and then the output signal of the second magnetic sensor is VB2=VA0−S2*H, wherein VA0=(VB1+VB2)/2 and H=(VB1−VB2)/(2*S2) to obtain VA0 after calibration and also the value of the external magnetic field. The second magnetic sensor is used to conduct SET operation, wherein the first magnetic sensor is used in calibration and the second magnetic sensor is used to conduct the measurement of an external field, and then the first magnetic sensor conducts the SET operation. Adding a self-detection current upon self-detection coils of the first magnetic sensor to calibrate a sensitivity of the first magnetic sensor to S1, and then the output signal of a second magnetic sensor is VB=VB0+S1*H, wherein VB0 denotes a zero signal of the second magnetic sensor and H denotes the external magnetic field. A signal processing circuit is used to adjust the output signal of the first magnetic sensor to VA2=VB0−S1*H, wherein VB0=(VA1+VA2)/2 and H=(VA1−VA2)/(2*S1) to obtain VB0 after calibration and also the value of the external magnetic field. The first magnetic sensor is then used to conduct SET operation.
In some embodiments, a first magnetic sensor is used to continue the measurement, and a second magnetic sensor is used in calibration. When the first magnetic sensor is used to conduct the measurement of an external magnetic field, the second magnetic sensor is used in calibration, and then the second magnetic sensor conducts the SET operation. a self-detection current is added upon self-detection coils of the second magnetic sensor to calibrate a sensitivity of the second magnetic sensor to S2, and then the output signal of the first magnetic sensor is VA=VA0+S2*H, wherein VA0 denotes a zero signal of the first magnetic sensor and H denotes the external magnetic field. A signal processing circuit is used to adjust the output signal of the second magnetic sensor to VA, and then the output signal of the second magnetic sensor is VB1=VA0±S2*H. The second magnetic sensor is then used to conduct SET operation, and the output signal of the second magnetic sensor is VB2=VA0−S2*H, wherein VA0=(VB1+VB2)/2 and H=(VB1−VB2)/(2*S2) to obtain VA0 after calibration and also the value of the external magnetic field. The second magnetic sensor is then used to conduct SET operation.
An aspect of the present disclosure is to provide a current sensor comprising a first connection portion, a second connection portion, and a middle area connected with the first connection portion and the second connection portion. That is, the first magnetic sensor and the second magnetic sensor of the illustrated magnetic sensor apparatus are all located either above or below the first connection portion, or two magnetic sensing units of the first magnetic sensor are respectively located on both sides of the middle area, and the second magnetic sensor is located either above or below both the first connection portion and the second connection portion.
Compared with existing technology, the magnetic sensing apparatus of the present disclosure applies two magnetic sensors and a signal processing circuit to alternatively calibrate two magnetic sensors or use one of these two magnetic sensors to calibrate the other one. This ensures that there will be at least one magnetic sensor used to measure. Simultaneously, the other magnetic sensor is used to calibrate the sensitivity and zero signal for enhancing high accuracy of the measurement.
These and other features, aspects, and advantages of the present disclosure will become better understood with regard to the following description, appended claims, and accompanying drawings.
The detailed description of the present disclosure is presented largely in terms of procedures, steps, logic blocks, processing, or other symbolic representations that directly or indirectly resemble the operations of devices or systems contemplated in the present disclosure. These descriptions and representations are typically used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art.
Reference herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be comprised in at least one embodiment of the present disclosure. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Further, the order of blocks in process flowcharts or diagrams or the use of sequence numbers representing one or more embodiments of the present disclosure do not inherently indicate any particular order nor imply any limitations in the present disclosure.
In Status 1, specific operations are performed as follow.
A second magnetic sensor is used to conduct SET operation.
A self-detection current is added upon self-detection coils of the second magnetic sensor to calibrate a sensitivity of the second magnetic sensor to S2, and then the output signal of the first magnetic sensor is VA=VA0+S2*H, wherein VA0 denotes a zero signal of the first magnetic sensor and H denotes the external magnetic field.
A signal processing circuit is used to adjust the output signal of a second magnetic sensor to VA, and then the output signal of the second magnetic sensor is VB1=VA0+S2*H.
A second magnetic sensor is used to conduct RESET operation, and then the output signal of the second magnetic sensor is VB2=VA0−S2*H, wherein VA0=(VB1+VB2)/2 and H=(VB1−VB2)/(2*S2), to obtain VA0 after calibration and also the value of the external magnetic field.
A second magnetic sensor is used to conduct SET operation.
in Status 3, specific operations are performed as follow:
A first magnetic sensor is used to conduct SET operation.
A self-detection current is added upon self-detection coils of a first magnetic sensor to calibrate the sensitivity of the first magnetic sensor to S1, and then the output signal of a second magnetic sensor is VB=VB0+S1*H, wherein VB0 denotes a zero signal of the second magnetic sensor and H denotes the external magnetic field.
A signal processing circuit is used to adjust the output signal of a first magnetic sensor to VB, and then the output signal of the first magnetic sensor is VA1=VB0+S1*H;
A first magnetic sensor is used to conduct RESET operation, and then the output signal of the first magnetic sensor is VA2=VB0−S1*H, wherein VB0=(VA1+VA2)/2 and H=(VA1−VA2)/(2*S1), to obtain VB0 after calibration and also the value of the external magnetic field.
A first magnetic sensor is used to conduct SET operation.
In Status 2, specific operations are performed as follow.
A second magnetic sensor is used to conduct a SET operation.
A self-detection current is added upon self-detection coils of a second magnetic sensor to calibrate the sensitivity of the second magnetic sensor to S2. Then the output signal of the first magnetic sensor is VA=VA0+S2*H, wherein VA0 denotes the zero signal of the first magnetic sensor, and H denotes an external magnetic field.
A signal processing circuit is used to adjust the output signal of a second magnetic sensor to VA, and then the output signal of the second magnetic sensor is VB1=VA0+S2*H.
A second magnetic sensor is used to conduct RESET operation, and then the output signal of the second magnetic sensor is VB2=VA0−S2*H, wherein VA0=(VB1+VB2)/2 and H=(VB1−VB2)/(2*S2), to obtain VA0 after calibration, and also the value of the external magnetic field.
A second magnetic sensor is used to conduct SET operation.
It should be noted that any modification made by a person skilled in the art to the embodiments disclosed in the present disclosure would still be considered within the scope of the claims of the present application. Accordingly, the scope of the claims of the present application is not limited to the foregoing embodiments.
The herein-described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected”, or “operably coupled”, to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “operably couplable”, to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or logically interactable components.
Further, with respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
Moreover, it will be understood by those skilled in the art that, in general, terms used herein, and especially in the appended claims, e.g., bodies of the appended claims, are generally intended as “open” terms, e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc. It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to implementations containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an,” e.g., “a” and/or “an” should be interpreted to mean “at least one” or “one or more;” the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number, e.g., the bare recitation of “two recitations,” without other modifiers, means at least two recitations, or two or more recitations. Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention, e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc. In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention, e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc. It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
From the foregoing, it will be appreciated that various implementations of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various implementations disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201710492932.6 | Jun 2017 | CN | national |
