阅读说明：本技术 一种闭环式芯上反馈的宽量程垂直灵敏磁传感器 (Wide-range vertical sensitive magnetic sensor with feedback on closed-loop core ) 是由 白茹 王志强 钱正洪 于 2019-10-29 设计创作，主要内容包括：本发明公开了一种闭环式芯上反馈的宽量程垂直灵敏磁传感器,包括硅基衬底、通量引导器、磁敏电阻、信号反馈线圈、运算放大器和功率放大器,本发明通过在推拉式垂直灵敏的磁传感器芯片上设置在位信号反馈线圈,当通有反馈电流时信号反馈线圈上方的磁敏电阻敏感轴方向上产生大小相等方向相反的磁场信号,分别抵消原信号磁场,而形成闭环式反馈结构,有效改善传感器输出线性度,提高测量精度,降低功耗；利用磁敏电阻距通量引导器间距不同,进而使得磁敏电阻接收的水平方向磁场分量不同,实现分别对大磁场和小磁场不同量程检测的目的。(The invention discloses a wide-range vertical sensitive magnetic sensor fed back on a closed-loop core, which comprises a silicon-based substrate, a flux guider, a magneto-resistor, a signal feedback coil, an operational amplifier and a power amplifier, wherein the on-position signal feedback coil is arranged on a push-pull vertical sensitive magnetic sensor chip, when feedback current is introduced, magnetic field signals with equal magnitude and opposite directions are generated in the sensitive axis direction of the magneto-resistor above the signal feedback coil, and the magnetic field signals counteract the original signal magnetic field respectively to form a closed-loop feedback structure, thereby effectively improving the output linearity of the sensor, improving the measurement precision and reducing the power consumption; the purpose of detecting different measuring ranges of a large magnetic field and a small magnetic field is achieved by utilizing different distances between the magnetoresistors and the flux guider and further enabling the magnetoresistors to receive different horizontal magnetic field components.)

1. A wide-range vertical sensitive magnetic sensor fed back on a closed-loop core comprises a silicon-based substrate, a flux guider, four same magneto-resistors, a signal feedback coil, an operational amplifier and a power amplifier;

the method is characterized in that: the flux guider is of a long strip structure, four magnetoresistors are arranged on the same silicon-based substrate, two shielded magnetoresistors used for reference are arranged right below the flux guider, the left side and the right side of the flux guider are respectively provided with one magnetoresistor, the two magnetoresistors are bilaterally symmetrical about the flux guider, the sensitive axes of the two magnetoresistors are positioned on the same horizontal line and have the same direction, and the two magnetoresistors are perpendicular to the left side surface and the right side surface of the flux guider; the flux guider induces a vertical magnetic field signal to the in-plane direction, an in-plane magnetic field component is generated at the magneto-resistors on two sides of the flux guider, and the signal magnetic field components generated in the sensitive axis directions of the two magneto-resistors are equal in magnitude and opposite in direction;

the magneto-resistors which are symmetrical on the left side and the right side of the flux guider form a group of half bridges, two shielded magneto-resistors which are used for reference and arranged right below the flux guider form another group of half bridges, and the four magneto-resistors jointly form a push-pull output Wheatstone bridge structure; the signal feedback coil is in a U-shaped structure with two parallel sides, the signal feedback coil is arranged on a silicon-based substrate below the magnetoresistor, the two parallel sides of the signal feedback coil are respectively arranged right below the magnetoresistor on the left side and the right side of the flux guide, and the signal feedback coil generates magnetic field signals with equal size and opposite directions on the sensitive axis direction of the magnetoresistor on the two sides of the flux guide when the feedback current is supplied;

a detection resistor is arranged between the output end of the signal feedback coil and the grounding end; the output end of the Wheatstone bridge is connected with the input end of the operational amplifier, the output end of the operational amplifier is connected with the input end of the power amplifier, and the output end of the power amplifier is connected with the signal feedback coil to form a closed loop feedback structure.

2. The wide range, vertically sensitive, magnetic sensor with feedback on a closed-loop core of claim 1, wherein: the flux guider is made of nickel series, cobalt series or iron series soft magnetic materials.

3. The wide range, vertically sensitive, magnetic sensor with feedback on a closed-loop core of claim 1, wherein: the magneto-resistor is giant magneto-resistance resistor or tunnel junction magneto-resistance resistor.

4. The wide range, vertically sensitive, magnetic sensor with feedback on a closed-loop core of claim 1, wherein: the signal feedback coil is made of non-magnetic, low-resistance and good-conductivity metal silver, copper, aluminum, gold and titanium or alloy thereof.

5. A wide-range vertical sensitive magnetic sensor fed back on a closed-loop core comprises a silicon-based substrate, a flux guider, six same magneto-resistors, two signal feedback coils, an operational amplifier and a power amplifier; the method is characterized in that: the flux guider is of a long strip structure and is arranged on the same silicon substrate together with six magnetoresistors, two shielded magnetoresistors used for reference are arranged under the flux guider, the left side and the right side of the flux guider are respectively provided with two magnetoresistors, the two magnetoresistors close to the left side and the right side of the flux guider form a pair, the two magnetoresistors far away from the left side and the right side of the flux guider form a pair, each pair of magnetoresistors are bilaterally symmetrical relative to the flux guider, the directions of the sensitive axes of the six magnetoresistors are the same, and the flux guider and the six magnetoresistors are arranged at positions for detecting a magnetic field signal of a vertical plane; the two signal feedback coils are of U-shaped structures, the feedback coil of one U-shaped structure is arranged on the silicon-based substrate below the pair of magnetoresistors close to the left side edge and the right side edge of the flux guider, the feedback coil of the other U-shaped structure is arranged on the silicon-based substrate below the pair of magnetoresistors far away from the left side edge and the right side edge of the flux guider, and the two edges of the U-shaped structure are parallel to each other and are respectively arranged right below the two pairs of magnetoresistors on the two sides of the flux guider; a pair of magneto-resistors close to the flux guider and two shielded magneto-resistors used for reference arranged right below the flux guider form a Wheatstone bridge structure for push-pull output, and the Wheatstone bridge structure is used for detecting a magnetic field signal of a small-range vertical plane; a pair of magnetoresistors far away from the flux guider and two shielded magnetoresistors used for reference arranged right below the flux guider form another Wheatstone bridge structure for push-pull output, and the magnetoresistors are used for detecting magnetic field signals of a large-range vertical plane; the two pairs of Wheatstone bridge structures are designed to meet the requirements of the sensor chip on the detection of different measuring ranges of the magnetic field signals of the vertical plane;

the flux guider induces a vertical magnetic field signal to the in-plane direction and respectively generates magnetic leakage components in the directions of two pairs of magneto-resistor sensitive axes at the left side and the right side of the flux guider, after the vertical magnetic field signal is induced by the flux guider, the vertical magnetic field signal respectively generates magnetic leakage components with equal size and opposite directions in the direction of the first pair of magneto-resistor sensitive axes and generates magnetic leakage components with equal size and opposite directions in the direction of the second pair of magneto-resistor sensitive axes; when feedback current is fed, signal feedback coils below a pair of magnetoresistors close to the left side and the right side of the flux guider generate a magnetic leakage component feedback magnetic field for offsetting the sensitive axis direction of the magnetoresistors in the sensitive axis direction of the two magnetoresistors above the signal feedback coils; the signal feedback coils below a pair of magnetoresistors far away from the left side and the right side of the flux guider generate a magnetic leakage component feedback magnetic field for offsetting the sensitive axis direction of the magnetoresistors in the sensitive axis direction of the two magnetoresistors above the signal feedback coils;

the output ends of the two Wheatstone bridges are connected with the input end of the operational amplifier through switches, and the switches are used for selecting one of the two Wheatstone bridges as a detection bridge and indirectly have the function of selecting a measuring range; the operational amplifier amplifies the signal amplitude and outputs the amplified signal, the output end of the operational amplifier is connected to the input end of the power amplifier, the output end of the power amplifier is connected to the signal feedback coil, the other end of the feedback coil is connected in series with the resistor to be tested, and the other end of the resistor to be tested is grounded.

6. The wide range vertical sensitive magnetic sensor with feedback on closed-loop core of claim 5, wherein: the flux guider is made of nickel series, cobalt series or iron series soft magnetic materials.

7. The wide range vertical sensitive magnetic sensor with feedback on closed-loop core of claim 5, wherein: the magneto-resistor is giant magneto-resistance resistor or tunnel junction magneto-resistance resistor.

8. The wide range vertical sensitive magnetic sensor with feedback on closed-loop core of claim 5, wherein: the signal feedback coil is made of non-magnetic, low-resistance and good-conductivity metal silver, copper, aluminum, gold and titanium or alloy thereof.

Technical Field

The invention belongs to the technical field of magnetic sensors, and relates to a wide-range vertical sensitive magnetic sensor with feedback on a closed-loop core.

Background

With the rapid development of the field of magnetic sensors, the application of the magnetic sensors is more and more extensive, the current vertical magnetic sensors are widely applied to the field of consumer electronics such as mobile phones and the like and electronic compass mobile devices, and the products require smaller packaging size and higher measurement stability.

Most of the existing vertical sensitive magnetic sensors are designed in a Z-axis packaging mode, and the Z-axis packaging is a method for packaging a sensitive axis of a sensing chip in a vertical and horizontal plane, for example, patent CN 102426344 a, entitled invention patent of a three-axis magnetic field sensor, which adopts a three-sensor packaging integration method, wherein the Z-axis sensor is placed in a vertical plane to measure a magnetic field in a vertical direction. The sensor manufactured by the method has the advantages of large volume, high packaging cost, complex process, low stability, easy packaging fracture and the like. The name of patent CN103995240B is a magnetoresistive Z-axis gradient sensor chip, which uses a flux guide to direct the Z-axis magnetic field component in the XY plane. The invention primarily utilizes flux directors to direct the Z-axis magnetic field in the XY plane for the measurement of Z-axis gradients. In order to ensure the sensitivity of the sensor composed of the conventional magnetic sensing element, the interval of the magnetic field detection is mostly within plus or minus 10Gs, and the detection capability for a larger magnetic field is insufficient.

Although a single-core integrated vertical sensitive magnetic sensor exists, an open-loop design is adopted at present, for example, the name of application No. 201820341886.X is a push-pull vertical sensitive magnetic sensor, which converts a Z-axis magnetic field in a vertical direction into a leakage magnetic field component in a plane by using a flux guide to realize magnetic field detection in the vertical direction, but in the design, a magnetoresistor is easy to be magnetically saturated under the condition of measuring a large magnetic field, hysteresis is large during measurement, the measurement bandwidth, the measurement precision and the linearity of the sensor are influenced to a great extent, and the open-loop design has poor linearity and low measurement precision, and is difficult to meet the requirements of modern industries.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a wide-range vertical sensitive magnetic sensor with feedback on a closed-loop core.

The invention comprises a silicon-based substrate, a flux guider, four same magneto-resistors, a signal feedback coil, an operational amplifier and a power amplifier;

the flux guider is of a long strip structure, four magnetoresistors are arranged on the same silicon-based substrate, two shielded magnetoresistors used for reference are arranged right below the flux guider, the left side and the right side of the flux guider are respectively provided with one magnetoresistor, the two magnetoresistors are bilaterally symmetrical about the flux guider, the sensitive axes of the two magnetoresistors are positioned on the same horizontal line and have the same direction, and the two magnetoresistors are perpendicular to the left side surface and the right side surface of the flux guider; the flux guider induces a vertical magnetic field signal to the in-plane direction, an in-plane magnetic field component is generated at the magneto-resistors on two sides of the flux guider, and the signal magnetic field components generated in the sensitive axis directions of the two magneto-resistors are equal in magnitude and opposite in direction;

the magneto-resistors which are symmetrical on the left side and the right side of the flux guider form a group of half bridges, two shielded magneto-resistors which are used for reference and arranged right below the flux guider form another group of half bridges, and the four magneto-resistors jointly form a push-pull output Wheatstone bridge structure; the signal feedback coil is in a U-shaped structure with two parallel sides, the signal feedback coil is arranged on a silicon-based substrate below the magnetoresistor, the two parallel sides of the signal feedback coil are respectively arranged right below the magnetoresistor on the left side and the right side of the flux guide, and the signal feedback coil generates magnetic field signals with equal size and opposite directions on the sensitive axis direction of the magnetoresistor on the two sides of the flux guide when the feedback current is supplied;

a detection resistor is arranged between the output end of the signal feedback coil and the grounding end; the output end of the Wheatstone bridge is connected with the input end of the operational amplifier, the output end of the operational amplifier is connected with the input end of the power amplifier, and the output end of the power amplifier is connected with the signal feedback coil to form a closed loop feedback structure.

The invention also comprises a silicon substrate, a flux guider, six same magneto-resistors, two signal feedback coils, an operational amplifier and a power amplifier; the method is characterized in that: the flux guider is of a long strip structure and is arranged on the same silicon substrate together with six magnetoresistors, two shielded magnetoresistors used for reference are arranged under the flux guider, the left side and the right side of the flux guider are respectively provided with two magnetoresistors, the two magnetoresistors close to the left side and the right side of the flux guider form a pair, the two magnetoresistors far away from the left side and the right side of the flux guider form a pair, each pair of magnetoresistors are bilaterally symmetrical relative to the flux guider, the directions of the sensitive axes of the six magnetoresistors are the same, and the flux guider and the six magnetoresistors are arranged at positions for detecting a magnetic field signal of a vertical plane; the two signal feedback coils are of U-shaped structures, the feedback coil of one U-shaped structure is arranged on the silicon-based substrate below the pair of magnetoresistors close to the left side edge and the right side edge of the flux guider, the feedback coil of the other U-shaped structure is arranged on the silicon-based substrate below the pair of magnetoresistors far away from the left side edge and the right side edge of the flux guider, and the two edges of the U-shaped structure are parallel to each other and are respectively arranged right below the two pairs of magnetoresistors on the two sides of the flux guider; a pair of magneto-resistors close to the flux guider and two shielded magneto-resistors used for reference arranged right below the flux guider form a Wheatstone bridge structure for push-pull output, and the Wheatstone bridge structure is used for detecting a magnetic field signal of a small-range vertical plane; a pair of magnetoresistors far away from the flux guider and two shielded magnetoresistors used for reference arranged right below the flux guider form another Wheatstone bridge structure for push-pull output, and the magnetoresistors are used for detecting magnetic field signals of a large-range vertical plane; the two pairs of Wheatstone bridge structures are designed to meet the requirements of the sensor chip on the detection of different measuring ranges of the magnetic field signals of the vertical plane;

the flux guider induces a vertical magnetic field signal to the in-plane direction and respectively generates magnetic leakage components in the directions of two pairs of magneto-resistor sensitive axes at the left side and the right side of the flux guider, after the vertical magnetic field signal is induced by the flux guider, the vertical magnetic field signal respectively generates magnetic leakage components with equal size and opposite directions in the direction of the first pair of magneto-resistor sensitive axes and generates magnetic leakage components with equal size and opposite directions in the direction of the second pair of magneto-resistor sensitive axes; when feedback current is fed, signal feedback coils below a pair of magnetoresistors close to the left side and the right side of the flux guider generate a magnetic leakage component feedback magnetic field for offsetting the sensitive axis direction of the magnetoresistors in the sensitive axis direction of the two magnetoresistors above the signal feedback coils; the signal feedback coils below a pair of magnetoresistors far away from the left side and the right side of the flux guider generate a magnetic leakage component feedback magnetic field for offsetting the sensitive axis direction of the magnetoresistors in the sensitive axis direction of the two magnetoresistors above the signal feedback coils;

the output ends of the two Wheatstone bridges are connected with the input end of the operational amplifier through switches, and the switches are used for selecting one of the two Wheatstone bridges as a detection bridge and indirectly have the function of selecting a measuring range; the operational amplifier amplifies the signal amplitude and outputs the amplified signal, the output end of the operational amplifier is connected to the input end of the power amplifier, the output end of the power amplifier is connected to the signal feedback coil, the other end of the feedback coil is connected in series with the resistor to be tested, and the other end of the resistor to be tested is grounded.

Preferably, the flux guide is made of a nickel-based, cobalt-based or iron-based soft magnetic material.

Preferably, the magneto-resistor is giant magneto-resistance or tunnel junction magneto-resistance.

Preferably, the signal feedback coil is made of non-magnetic, low-resistance and good-conductivity metal silver, copper, aluminum, gold titanium or alloy thereof.

According to the invention, the in-place signal feedback coil is arranged on the push-pull type vertical sensitive magnetic sensor chip, when feedback current is conducted, magnetic field signals with equal magnitude and opposite directions are generated in the directions of two pairs of magneto-resistor sensitive axes above the signal feedback coil, and the original signal magnetic fields are respectively offset, so that a closed loop type feedback structure is formed, the output linearity of the sensor is effectively improved, the measurement precision is improved, and the power consumption is reduced; the distance between the two groups of magnetoresistors and the flux guider can be different, so that the horizontal magnetic field components received by the two groups of magnetoresistors are different, and two pairs of push-pull bridges formed by the six same magnetoresistors realize the purpose of respectively detecting different ranges of a large magnetic field and a small magnetic field.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 is a block diagram of an overall system according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of the vertical magnetic field induced by the flux guide under the action of the external magnetic field according to one embodiment of the present invention;

FIG. 4 is a schematic diagram of a push-pull Wheatstone bridge according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a feedback magnetic field counteracting an original magnetic field under the action of a signal feedback coil according to a first embodiment of the present invention;

FIG. 6 is a diagram illustrating a Wheatstone bridge state under the action of a signal feedback coil according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram according to a second embodiment of the present invention;

FIG. 8 is a diagram of a general system according to a second embodiment of the present invention;

FIG. 9 is a schematic diagram of the vertical magnetic field induced by the flux guide under the action of the external magnetic field in the second embodiment of the present invention;

FIG. 10 is a schematic diagram of a push-pull Wheatstone bridge according to a second embodiment of the invention;

FIG. 11 is a schematic diagram of the feedback magnetic field counteracting the original magnetic field under the action of the signal feedback coil according to the second embodiment of the present invention;

fig. 12 is a schematic diagram of a wheatstone bridge state under the action of the signal feedback coil in the second embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.