CN115236391A - Magnetic sensing chip and closed-loop feedback current sensor - Google Patents
Magnetic sensing chip and closed-loop feedback current sensor Download PDFInfo
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- CN115236391A CN115236391A CN202210761512.4A CN202210761512A CN115236391A CN 115236391 A CN115236391 A CN 115236391A CN 202210761512 A CN202210761512 A CN 202210761512A CN 115236391 A CN115236391 A CN 115236391A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/32—Compensating for temperature change
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
- G01R15/20—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using galvano-magnetic devices, e.g. Hall-effect devices, i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices
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Abstract
A magnetic sensing chip and a closed-loop feedback current sensor are provided, the magnetic sensing chip comprises a magnetic sensing unit, a thermistor and a feedback coil, the magnetic sensing unit comprises a magneto-resistance element, and the thermistor is arranged on an electrode layer of the magneto-resistance element. The closed-loop feedback current sensor comprises a magnetic sensing chip and a signal processing circuit; the signal processing circuit comprises a magnetic balance circuit, a current sampling circuit and a temperature compensation circuit; the magnetic balance circuit provides current for the feedback coil according to the signal output by the magnetic sensing unit, so that the feedback coil generates a feedback magnetic field; the current sampling circuit is connected with the feedback coil, and is used for collecting and outputting a current signal of the feedback coil; the temperature compensation circuit is connected with the thermistor and the current sampling circuit, and outputs the detection result after compensating the detection result according to the signals output by the thermistor and the current sampling circuit. The thermistor is integrated in the magnetic sensing chip and can more accurately reflect the temperature information of the detection area, so that more accurate temperature drift compensation is performed on the current sensor.
Description
The invention relates to a divisional application of an invention patent application with the application number of 202010495259.3, the application date of 2020, 6 months and 3 days, and the invention name of a magnetic sensing chip, a closed-loop feedback current sensor and a preparation method thereof.
Technical Field
The invention belongs to the technical field of sensing measurement, and particularly relates to a magnetic sensing chip and a closed-loop feedback current sensor.
Background
The current sensor is of two types, namely an open-loop sensor and a closed-loop sensor, and the open-loop current sensor adopts a magnetic sensitive element to generate an analog signal proportional to the measured current so as to achieve the purpose of measuring the current. The open-loop current sensor has a simple structure and strong overload capacity, but the open-loop mode causes poor linearity, and the measurement accuracy of the current sensor is influenced.
Compared with an open-loop current sensor, the current sensor with closed-loop feedback has higher sensitivity and wider measurement range. The closed-loop feedback current sensor includes a closed-loop feedback current sensor based on magnetic modulation and a closed-loop feedback current sensor based on a magnetic sensor.
A closed loop feedback current sensor based on magnetic modulation is characterized in that a magnetic field signal of a current to be measured is loaded on a fundamental wave generated by self-excitation through a modulation circuit, the loaded fundamental wave is removed by a demodulation circuit, and the magnetic field signal of the current to be measured is left; the signal processing circuit controls the size of a magnetic field generated by the feedback coil winding by judging a magnetic field signal of the detected current so as to achieve the magnetic balance state of the current sensor; when the current sensor is in a magnetic balance state, the magnitude of the measured current can be calculated by measuring the current in the feedback coil winding. However, the closed-loop feedback current sensor based on magnetic modulation can only be used for measuring a small direct current signal generally, and the application scenario is limited.
The closed-loop feedback current sensor based on the magnetic sensor detects a magnetic field by adopting the magnetic sensor, and a signal processing circuit adjusts the current of a feedback coil winding according to the magnetic field detected by the magnetic sensor, so that the feedback magnetic field and the measured current magnetic field are equal in size and opposite in direction, and the magnetic field near the magnetic sensor reaches an equilibrium state; when the current sensor is in a magnetic balance state, the magnitude of the measured current can be calculated by measuring the current in the feedback coil winding. The closed-loop feedback current sensor based on the magnetic sensor can measure alternating current and direct current signals, the application scene is wider, and the circuit structure is simpler compared with the circuit structure in the closed-loop feedback current sensor based on magnetic modulation. However, due to the influence of the temperature characteristics of the magnetic field detection part and the feedback coil winding, the sensitivity of the closed-loop feedback current sensor is influenced by the change of the environmental temperature, and the measurement accuracy is further influenced. For this reason, temperature drift compensation needs to be performed on the current sensor to ensure the measurement accuracy of the current sensor at different temperatures.
Disclosure of Invention
The invention aims to provide a magnetic sensing chip and a closed-loop feedback current sensor which can perform temperature compensation and have higher measurement accuracy.
In order to achieve the purpose, the invention adopts the following technical solutions:
the magnetic sensing chip comprises a magnetic sensing unit, a thermistor and a feedback coil, wherein the magnetic sensing unit comprises a magneto-resistance element, and the thermistor is arranged on an electrode layer of the magneto-resistance element.
Further, the preparation method of the magnetic sensing chip comprises the following steps:
providing a substrate;
depositing a lower electrode layer, a pinning layer, a nonmagnetic layer, and a free layer on a substrate;
etching a magneto-resistor element area and a thermistor area according to the layout;
depositing an upper electrode layer, preparing an electrical connection structure, and electrically connecting the magnetoresistance element and the thermistor;
depositing a feedback coil layer, etching a feedback coil, and connecting the feedback coil with a wiring terminal;
and packaging the chip to obtain the magnetic sensing chip.
Furthermore, the thermistor is connected with a temperature compensation link outside the magnetic sensing chip to form a temperature drift compensation circuit.
Furthermore, the feedback coil is arranged above the magnetic sensing unit, the feedback coil is of a planar spiral line structure, and the spiral line plane of the feedback coil is perpendicular to the sensing direction of the magnetic sensing unit.
Further, the feedback coil is formed by etching a conductive material.
The invention also provides a closed-loop feedback current sensor which comprises the magnetic sensing chip and a signal processing circuit; the signal processing circuit comprises a magnetic balance circuit, a current sampling circuit and a temperature compensation circuit; the magnetic balance circuit is respectively connected with the magnetic sensing unit and the feedback coil and used for providing current for the feedback coil according to the signal output by the magnetic sensing unit so as to enable the feedback coil to generate a feedback magnetic field; the current sampling circuit is connected with the feedback coil and used for acquiring and outputting a current signal of the feedback coil; the temperature compensation circuit is respectively connected with the thermistor and the current sampling circuit and is used for compensating and outputting a detection result according to signals output by the thermistor and the current sampling circuit.
Further, the magnetic balance circuit comprises a differential voltage sampling circuit and a push-pull emitter follower which are sequentially connected, the differential voltage sampling circuit is electrically connected with the magnetic sensing unit, and the push-pull emitter follower is electrically connected with the feedback coil.
Furthermore, the temperature compensation circuit comprises a temperature sampling circuit and an addition proportional circuit which are sequentially connected, the temperature sampling circuit is electrically connected with the thermistor, and the addition proportional circuit is connected with the output end of the temperature sampling circuit and the output end of the current sampling circuit and outputs a measurement result.
Further, the signal processing circuit comprises a first analog-to-digital converter, a push-pull emitter follower, a digital-to-analog converter, a current sampling circuit, a second analog-to-digital converter, a temperature sampling circuit, a third analog-to-digital converter and a micro-control processor; the push-pull emitter follower forms a magnetic balance circuit, and the temperature sampling circuit forms a temperature compensation circuit.
Further, the micro control processor is electrically connected to the magnetic sensing unit through the first analog-to-digital converter, electrically connected to the push-pull emitter follower through the digital-to-analog converter, electrically connected to the current sampling circuit through the second analog-to-digital converter, and electrically connected to the temperature sampling circuit through the third analog-to-digital converter; the temperature sampling circuit is electrically connected with the thermistor, the push-pull emitter follower is electrically connected with the feedback coil winding, and the current sampling circuit is electrically connected with the feedback coil; the current sampling circuit is used for converting a current signal acquired from the feedback coil into a voltage signal, converting the voltage signal into a digital signal through the second analog-to-digital converter and transmitting the digital signal to the micro-control processor; the temperature sampling circuit is used for converting the acquired voltage signal into a digital signal through the third analog-to-digital converter and then sending the digital signal to the micro-control processor; and the micro-control processor is used for processing the voltage signal sampled by the temperature and the voltage signal sampled by the current to obtain the output signal of the current sensor after temperature compensation.
According to the technical scheme, the thermistor is integrated in the magnetic sensing chip, the thermistor element is connected with a temperature compensation link outside the chip to form the temperature drift compensation circuit, and the temperature information fed back by the thermistor is more accurate and can more accurately reflect the temperature information of the detection area because the temperature acquisition area of the thermistor is closer to the magnetic field detection area, so that more accurate temperature drift compensation is performed on the current sensor.
Drawings
In order to illustrate the embodiments of the invention more clearly, reference will now be made briefly to the embodiments or figures that are required in the description of the prior art, it being clear that the figures in the description that follows are only some embodiments of the invention and that, without inventive step, other figures can also be derived from them by a person skilled in the art.
FIG. 1 is a schematic structural view of example 1 of the present invention;
FIG. 2 is a circuit block diagram of embodiment 1 of the present invention;
fig. 3 is a schematic structural diagram of a magnetic sensor chip according to embodiment 1 of the present invention;
fig. 4 is a circuit block diagram of embodiment 2 of the present invention.
Detailed Description
In order to make the aforementioned and other objects, features and advantages of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
Example 1
Referring to fig. 1 and 2, the closed-loop feedback current sensor of the present embodiment includes a housing 10, and a magnetic sensing chip 1 and a signal processing circuit 20 disposed in the housing 10, wherein the signal processing circuit includes a magnetic balance circuit 2, a temperature compensation circuit 3, and a current sampling circuit 4. This embodiment has a circular opening in the center of the housing 10 through which the conductor 21 to be tested can pass. The magnetic sensing chip 1 and the signal processing circuit 20 are respectively disposed on the circuit board, the magnetic sensitivity direction of the magnetic sensing chip 1 (magnetic sensing unit) is perpendicular to the tested conductor 21, and the signal processing circuit 20 is electrically connected to the magnetic sensing chip 1 through a pin or a wire. In other embodiments, the housing may not have an opening, and this embodiment has an opening in the center of the housing for easy installation and fixation.
In the present embodiment, a feedback coil and a thermistor are integrated in the magnetic sensor chip 1. The magnetic sensing chip 1 includes a magnetic sensing unit 1-1 composed of magnetoresistive elements, a feedback coil 1-2, and a thermistor 1-3. The magnetic sensing unit 1-1 is used for measuring a magnetic field; the feedback coil 1-2 is used for generating a feedback magnetic field and is matched with the magnetic sensing unit 1-1 to realize that the current sensor reaches a magnetic balance state; the thermistor 1-3 is used for measuring temperature and collecting temperature information for the temperature compensation circuit. The magnetoresistive element of this embodiment is a TMR cell, and may be a GMR or an AMR, in addition to the TMR cell.
As shown in fig. 3, this embodiment has 4 sets of magnetoresistive elements (5, 6, 7, 8) deposited on the substrate of the magnetic sensor chip 1 using magnetron sputtering technology and is provided with 4 connection terminals (12, 13, 15, 16). Each group of magneto-resistor elements has the same structure and at least comprises an upper electrode layer, a lower electrode layer, a pinning layer, a free layer and a non-magnetic layer, wherein the non-magnetic layer is positioned between the pinning layer and the free layer, and the upper electrode layer and the lower electrode layer are respectively two outermost layers of the magneto-resistor elements. The magnetization direction of the pinning layer in the magnetic resistance element does not change along with the change of an external magnetic field, the magnetization direction of the free layer changes along with the change of the external magnetic field, and the resistance value of the magnetic resistance element changes along with the change of an included angle between the magnetization direction of the free layer and the magnetization direction of the pinning layer, so that the detection of the magnetic field is realized. The magneto-resistance elements are connected in a bridge mode to form a magnetic sensing unit 1-1 of a full-bridge structure, differential voltage signals are output outwards, and the magneto-resistance elements are located on a bridge arm of the full-bridge structure. Each connecting terminal is respectively connected with two adjacent bridge arms. Of the 4 connection terminals, one pair of connection terminals (13, 15) is an input terminal, an external power supply provides a voltage drop for the magnetic sensing chip 1 through the input terminal to enable the full-bridge circuit to be in an operating state, the other pair of connection terminals (12, 16) is an output terminal, and the magnetic sensing chip 1 outputs a differential voltage signal related to a magnetic field through the output terminal.
The thermistor of the embodiment is a ruthenium resistor 4 integrated on the substrate of the magnetic sensing chip 1, the ruthenium resistor 4 is used for collecting the temperature information of the magnetic field detection area, and the ruthenium resistor 4 is connected with the temperature compensation circuit 3 through connecting terminals (10, 14). The ruthenium resistor 4 and the magnetoresistive element are deposited on the same substrate but in two mutually independent areas on the substrate (magnetic sensor chip). Ruthenium is one of materials for preparing an electrode layer and a pinning layer of a tunnel junction magneto-resistance element (TMR), and the pinning layer is thin and is not suitable for preparing a thermistor, so that the ruthenium resistor is preferably arranged on the electrode layer, and compared with a conventional thermistor made of materials such as platinum, copper and nickel, the thermistor is formed by utilizing the electrode layer and is integrated in a magnetic sensing chip; on the other hand, because the ruthenium element is used for preparing the tunnel junction magneto-resistance element, only an independent temperature detection area needs to be divided in the magnetic sensing chip and is connected with the temperature compensation circuit, the original preparation process of the magnetic sensing chip is basically unchanged, other equipment does not need to be added, and the control of the production cost and the realization of the miniaturization design are facilitated. When the magneto-resistance element is GMR, ruthenium material can be added into the preparation material, so that the thermistor can be integrated in a chip.
The feedback coil 1-2 is of a uniform plane spiral line structure prepared by adopting an MEMS (micro electro mechanical System) Process, and the feedback coil 1-2 is formed by etching a conductive material. The feedback coil 1-2 of the invention is a plane structure, and compared with the existing feedback coil winding wound on a magnetic ring, the volume of the feedback coil is reduced. The feedback coil 1-2 is provided (directly) above a full-bridge structure (magnetic sensing unit 1-1) formed by magnetoresistive elements. The spiral line plane of the feedback coil 1-2 is perpendicular to the sensitive direction of the magnetic sensing unit 1-1 (the sensitive direction of the magnetic sensing unit can be changed by changing the material or structure of the TMR). Two ends of the feedback coil 1-2 are connected with the magnetic balance circuit 2 and the temperature compensation circuit 3 through wiring terminals (11, 17), and feedback current output by the magnetic balance circuit 1-2 flows to the feedback coil 1-2 through the wiring terminals, so that the feedback coil 1-2 is in a working state, and a uniform magnetic field is generated in the coil. The feedback coil 1-2 outputs a current signal to the temperature compensation circuit 3.
As shown in FIG. 2, a magnetic sensing unit 1-1 in a magnetic sensing chip 1 is connected to a magnetic balance circuit 2 through an output terminal, the magnetic balance circuit 2 of the present embodiment includes a differential voltage sampling circuit 2-1 and a push-pull emitter follower 2-2 connected in sequence, the differential voltage sampling circuit 2-1 is used for collecting a differential voltage signal V output by the magnetic sensing unit 1-1 M . The push-pull emitter follower 2-2 is connected with the feedback coil 1-2 and provides current for the feedback coil 1-2, so that the feedback coil 1-2 generates a feedback magnetic field H, and the current sensor reaches a magnetic balance state. The push-pull emitter follower 2-2 generates a current I output to the feedback coil 1-2 according to the differential voltage signal s . Feedback lineThe ring 1-2 is connected with the temperature compensation circuit 3 through the current sampling circuit 4, and outputs a current signal to the temperature compensation circuit 3.
The temperature compensation circuit 3 of the present embodiment includes a temperature sampling circuit 3-1 and an addition ratio circuit 3-2 connected in sequence. Wherein the temperature sampling circuit 3-1 is connected with the thermistor 1-3 (ruthenium resistor) and outputs a voltage signal V proportional to the temperature information T . The current sampling circuit 4 is connected with the feedback coil 1-2 and collects the current signal I of the feedback coil 1-2 S And feeding back the current signal I in the coil 1-2 S Converted into a voltage signal V S And outputs to the temperature compensation circuit 3. The addition proportion circuit 3-2 is connected with the output end of the temperature sampling circuit 3-1 and the output end of the current sampling circuit 4 to sample the temperature of the voltage signal V T Voltage signal V sampled with current S Adding and amplifying to obtain the output signal V of the temperature compensated current sensor o 。
The working principle of this embodiment is explained below with reference to fig. 1:
referring to fig. 1, when the current sensor performs measurement, a conductor 21 to be measured passes through an opening of the housing 10, and when a current flows through the conductor 21 to be measured, a magnetic field H is generated around the conductor 21 to be measured P (ii) a The magnetic sensing chip 1 detects the magnitude of the magnetic field at the position where the magnetic sensing chip is positioned and outputs a differential voltage signal V M (ii) a The magnetic balance circuit 2 collects the differential voltage signal V output by the magnetic sensing chip 1 M And adjusting the input current I of the feedback coil 1-2 S (ii) a Feedback coil 1-2 at current I S Under the action of the magnetic field, a feedback magnetic field is generated inside the coil; when the differential voltage signal V M When the magnetic flux is zero, the magnetic field generated by the measured conductor 21 is equal to the magnetic field generated by the feedback coil winding and opposite in direction, that is, the magnetic flux inside the feedback coil winding is zero.
The preparation method of the sensor chip of the present embodiment is as follows:
providing a substrate;
depositing a lower electrode layer, a pinning layer, a non-magnetic layer and a free layer on a substrate, wherein the lower electrode layer is prepared from a ruthenium material;
etching a magneto-resistance element region and a thermistor region according to the layout;
depositing an upper electrode layer, preparing an electrical connection structure which comprises a connection terminal and a wiring terminal connected with the magneto-resistor element, the thermistor and the feedback coil, and electrically interconnecting the magneto-resistor element and the thermistor;
depositing a feedback coil layer, etching a feedback coil with a planar spiral line structure, and connecting the feedback coil with a wiring terminal;
and packaging the chip.
Example 2
This example differs from example 1 in that: in the embodiment, a circuit with an integration link in a signal processing circuit is replaced by digital signal processing so as to reduce the temperature drift caused by the integration circuit. The signal processing circuit 20 of the present embodiment includes a first analog-to-digital converter 2-1, a push-pull emitter follower 2-2, a digital-to-analog converter 2-3, a current sampling circuit 4, a second analog-to-digital converter 2-5, a temperature sampling circuit 2-6, a third analog-to-digital converter 2-7, and a micro control processor 2-8. The push-pull emitter follower 2-2 forms a magnetic balance circuit, and the temperature sampling circuit 2-6 forms a temperature compensation circuit. The first analog-to-digital converter 2-1 is connected with the magnetic sensing unit 1-1 and used for collecting a voltage signal V output by the magnetic sensing unit 1-1 M And converts the acquired voltage signal into a digital signal and sends the digital signal to the micro-control processor 2-8. Microcontroller processor 2-8 pairs of voltage signals V M After processing, outputting an instruction to the push-pull emitter follower 2-2 through a digital-to-analog converter 2-3 connected with the push-pull emitter follower 2-2, wherein the push-pull emitter follower 2-2 is connected with the feedback coil winding 1-2 and provides current for the feedback coil winding 1-2, so that the feedback coil winding 1-2 generates a feedback magnetic field, and the current sensor reaches a magnetic balance state. The feedback coil 1-2 is connected with a current sampling circuit 4, and the current sampling circuit 4 is used for collecting a current signal I from the feedback coil 1-2 S Converted into a voltage signal V S And the voltage signal V is converted by a second A/D converter 2-5 S Converted into digital signals and transmitted to the micro-control processor 2-8. The temperature sampling circuit 2-6 is connected with the thermistor 1-3, and the temperature sampling circuit 2-6 acquires a voltage signal V through the third analog-to-digital converter 2-7 T Is converted intoThe digital signal is then sent to the micro-controller processor 2-8. The micro-control processor 2-8 samples the voltage signal of the temperature and the voltage signal V of the current S And after processing, obtaining an output signal D of the current sensor after temperature compensation.
The magnetic balance circuit and the temperature compensation circuit of the present invention are the same as those of the current sensor using the common thermistor for temperature compensation, and are not the point of the present invention, and are not described herein again.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. The magnetic sensing chip is characterized by comprising a magnetic sensing unit, a thermistor and a feedback coil, wherein the magnetic sensing unit comprises a magneto-resistor element, and the thermistor is arranged on an electrode layer of the magneto-resistor element.
2. The magnetic sensing chip according to claim 1, wherein the method for manufacturing the magnetic sensing chip comprises the steps of:
providing a substrate;
depositing a lower electrode layer, a pinning layer, a nonmagnetic layer, and a free layer on a substrate;
etching a magneto-resistance element region and a thermistor region according to the layout;
depositing an upper electrode layer, preparing an electrical connection structure, and electrically connecting the magnetoresistance element and the thermistor;
depositing a feedback coil layer, etching a feedback coil, and connecting the feedback coil with a wiring terminal;
and packaging the chip to obtain the magnetic sensing chip.
3. The magnetic sensor chip according to claim 1, wherein the thermistor is connected to a temperature compensation link external to the magnetic sensor chip to form a temperature drift compensation circuit.
4. The magnetic sensing chip according to claim 1, wherein the feedback coil is disposed above the magnetic sensing unit, the feedback coil has a planar spiral structure, and a spiral plane of the feedback coil is perpendicular to a sensitive direction of the magnetic sensing unit.
5. The magnetic sensing chip of claim 1, wherein the feedback coil is etched from a conductive material.
6. A closed-loop feedback current sensor comprising the magnetic sensing chip of any one of claims 1-5, and a signal processing circuit;
the signal processing circuit comprises a magnetic balance circuit, a current sampling circuit and a temperature compensation circuit;
the magnetic balance circuit is respectively connected with the magnetic sensing unit and the feedback coil and used for providing current for the feedback coil according to the signal output by the magnetic sensing unit so as to enable the feedback coil to generate a feedback magnetic field;
the current sampling circuit is connected with the feedback coil and used for acquiring and outputting a current signal of the feedback coil;
the temperature compensation circuit is respectively connected with the thermistor and the current sampling circuit and used for compensating and outputting a detection result according to signals output by the thermistor and the current sampling circuit.
7. The closed-loop feedback current sensor of claim 6, wherein said magnetic balancing circuit comprises a differential voltage sampling circuit and a push-pull emitter follower connected in series, said differential voltage sampling circuit being electrically connected to said magnetic sensing unit, said push-pull emitter follower being electrically connected to said feedback coil.
8. The closed-loop feedback current sensor of claim 6, wherein said temperature compensation circuit comprises a temperature sampling circuit and a summing proportional circuit connected in series, said temperature sampling circuit being electrically connected to said thermistor, said summing proportional circuit being connected to an output of said temperature sampling circuit and an output of said current sampling circuit and outputting a measurement result.
9. The closed loop feedback current sensor of claim 6, wherein said signal processing circuit comprises a first analog-to-digital converter, a push-pull emitter follower, a digital-to-analog converter, a current sampling circuit, a second analog-to-digital converter, a temperature sampling circuit, a third analog-to-digital converter, and a micro-control processor; the push-pull emitter follower forms a magnetic balance circuit, and the temperature sampling circuit forms a temperature compensation circuit.
10. A closed loop feedback current sensor as set forth in claim 9 wherein said microcontroller processor is electrically connected to said magnetic sensing unit through said first analog-to-digital converter, to said push-pull emitter follower through said digital-to-analog converter, to said current sampling circuit through said second analog-to-digital converter, and to said temperature sampling circuit through said third analog-to-digital converter;
the temperature sampling circuit is electrically connected with the thermistor, the push-pull emitter follower is electrically connected with the feedback coil winding, and the current sampling circuit is electrically connected with the feedback coil;
the current sampling circuit is used for converting a current signal acquired from the feedback coil into a voltage signal, converting the voltage signal into a digital signal through the second analog-to-digital converter and transmitting the digital signal to the micro-control processor;
the temperature sampling circuit is used for converting the acquired voltage signal into a digital signal through the third analog-to-digital converter and then sending the digital signal to the micro-control processor;
and the micro-control processor is used for processing the voltage signal sampled by the temperature and the voltage signal sampled by the current to obtain the output signal of the current sensor after temperature compensation.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115856396A (en) * | 2022-12-09 | 2023-03-28 | 珠海多创科技有限公司 | Sensing probe module, non-contact voltage measurement circuit, non-contact voltage measurement method and electronic equipment |
| CN115856396B (en) * | 2022-12-09 | 2023-08-29 | 珠海多创科技有限公司 | Sensing probe module, non-contact voltage measurement circuit, non-contact voltage measurement method and electronic equipment |
| CN116754820A (en) * | 2023-08-24 | 2023-09-15 | 冰零智能科技(常州)有限公司 | Current detection system and detection method thereof |
| CN116754820B (en) * | 2023-08-24 | 2023-10-24 | 冰零智能科技(常州)有限公司 | Current detection system and detection method thereof |
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