Full-band current sensor

Abstract

The application provides a full-band current sensor which detects a measured current according to a magnetic induction intensity generated by the measured current, and the full-band current sensor comprises a conductor, a Hall sensor and a planar coil sensor. The conductor is used for providing a flow channel for the measured current, so that the measured current can flow through the conductor; the Hall sensor is located around the conductor and is used for detecting low-frequency current in the measured current; and the planar coil sensor is located around the conductor and is used for detecting high-frequency current in the measured current. Compared with the prior art, the full-band current sensor of the application can eliminate the influence of an external magnetic field on one hand, thereby improving the detection precision of the current; and on the other hand, the full-band current detection can be realized.

Description

Technical field

[0001] The present invention relates to the technical field of current sensors, and in particular to a full-band current sensor. [Background Technology]

[0002] Current sensors for measuring current are widely used in various electronic devices. One prior art current sensor integrates a U-shaped conductor with two magnetoresistive sensors placed around it. The current being measured flows through the U-shaped conductor, and the two magnetoresistive sensors differentially measure the magnetic field generated by the current in the conductor, thereby detecting (or monitoring) the current being measured.

[0003] However, for current sensors based on the Hall effect, dynamic zero-point cancellation technology is usually used to eliminate the drift of the zero-point signal. However, its disadvantage is that it can only detect low-frequency currents.

[0004] Therefore, it is necessary to propose an improved technical solution to overcome the above problems. [Summary of the invention]

[0005] One of the purposes of the present invention is to provide a full-band current sensor, which, on the one hand, can effectively eliminate the influence of external magnetic fields, thereby improving the current detection accuracy; on the other hand, can realize full-band current detection.

[0006] According to one aspect of the present invention, a full-band current sensor is provided. It detects the current being measured based on the magnetic induction intensity generated by the current being measured. The full-band current sensor includes a conductor, a Hall effect sensor, and a planar coil sensor. The conductor provides a passage for the current being measured, allowing the current to flow through the conductor; the Hall effect sensor, located around the conductor, detects low-frequency currents in the current being measured; and the planar coil sensor, located around the conductor, detects high-frequency currents in the current being measured.

[0007] Furthermore, the Hall sensor includes a first Hall sensor unit and a second Hall sensor unit, and the first Hall sensor unit and the second Hall sensor unit are located around the conductor to form a differential output.

[0008] Furthermore, the planar coil sensor includes a first planar coil sensor unit and a second planar coil sensor unit, and the first planar coil sensor unit and the second planar coil sensor unit are located around the conductor to form a differential output.

[0009] Furthermore, the first planar coil sensor unit and the second planar coil sensor unit are collectively referred to as a planar coil sensor unit, and the planar coil sensor unit includes a planar coil, a differential amplifier and an integration circuit, and the two ports of the planar coil are respectively connected to the two input ends of the differential amplifier; the differential amplifier is used to amplify the difference between the voltages of its two input ends and output the amplified difference voltage through its output end; the input end of the integration circuit is connected to the output end of the differential amplifier, and its output end is connected to the output end of the planar coil sensor unit, and the integration circuit makes the output signal of its output end proportional to the time integral value of the input signal of its input end.

[0010] Furthermore, the planar coil sensor unit includes an operational amplifier, an integrating resistor and an integrating capacitor. The first input terminal of the operational discharger is connected to the output terminal of the differential amplifier via the integrating resistor, and its first input terminal is connected to its output terminal via the integrating capacitor, and its second input terminal is grounded.

[0011] Furthermore, the first input terminal and the second input terminal of the operational discharger are respectively the inverting input terminal and the non-inverting input terminal thereof.

[0012] Furthermore, the U-shaped conductor includes a first leg, a second leg, and a connecting portion connecting the first leg and the second leg, the first leg and the second leg are located on the same side of the connecting portion; the directions of the measured current flowing through the first leg and the second leg are opposite.

[0013] Furthermore, the first Hall sensor unit and the second Hall sensor unit are respectively located at the front and rear sides of the connection portion of the U-shaped conductor; the first planar coil sensor unit and the second planar coil sensor unit are respectively located at the front and rear sides of the connection portion of the U-shaped conductor.

[0014] Furthermore, the output of the first planar coil sensor unit is V 21 =μ0A eff (H 21 I+H0) / (RC); the output of the second planar coil sensor unit is V 22 =μ0A eff (-H 22 I+H0) / (RC); the output of the planar coil sensor is V 21 -V 22 =μ0A eff (H 21 +H 22 )I / (RC), where μ0 is the vacuum permeability, A eff is the effective area enclosed by the planar coil, R is the resistance value of the integral resistor, and C is the capacitance value of the integral capacitor.

[0015] Furthermore, the Hall sensor and the planar coil sensor are integrated on the same chip.

[0016] Compared to existing technologies, the current sensor of the present invention includes a conductor, a Hall effect sensor and a planar coil sensor disposed around the conductor. The Hall effect sensor is used to detect low-frequency currents in the measured current, while the planar coil sensor is used to detect high-frequency currents in the measured current. This full-band current sensor effectively eliminates the influence of external magnetic fields, thereby improving current detection accuracy; it also enables current detection across the entire frequency range.

Brief Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0018] Figure 1 FIG1 is a top view of a full-band current sensor in one embodiment of the present invention;

[0019] Figure 2 For the Figure 1 A schematic cross-sectional view of the AA section line;

[0020] Figure 3 For the Figure 1 A schematic cross-sectional view of the BB section line;

[0021] Figure 4 for Figure 1 The diagram shows a circuit diagram of a Hall sensor unit and a planar coil sensor unit in one embodiment. [Specific implementation method]

[0022] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] The term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to separate or selective embodiments that are mutually exclusive of other embodiments. Unless otherwise specified, the terms "connected," "connected," and "connected" herein, indicating electrical connection, refer to direct or indirect electrical connection.

[0024] Please refer to Figure 1 , which is a top view of a full-band current sensor in one embodiment of the present invention, which detects the measured current I according to the magnetic induction intensity (or magnetic field) generated by the measured current I.

[0025] The full-band current sensor includes a conductor 101, a Hall sensor 102, and a planar coil sensor 103. The conductor 101 provides a path for the measured current I to flow through the conductor 101. The Hall sensor 102, located around the conductor 101, detects low-frequency currents in the measured current I. The planar coil sensor 103, located around the conductor 101, detects high-frequency currents in the measured current I. In a preferred embodiment, the Hall sensor 102 and the planar coil sensor 103 can be integrated on the same chip.

[0026] exist Figure 1 In the illustrated embodiment, the conductor 101 is a U-shaped conductor comprising a first leg 101a, a second leg 101b, and a connecting portion 101c located between the first leg 101a and the second leg 101b. One end of the connecting portion 101c is connected to one end of the first leg 101a, and the other end of the connecting portion 101c is connected to one end of the second leg 101b. The first leg 101a and the second leg 101b are located on the same side of the connecting portion 101c. The measured current I flows from the other end of the first leg 101a into the U-shaped conductor 101, flows sequentially through the first leg 101a, the connecting portion 101c, and the second leg 101b, and then flows out of the U-shaped conductor 101 from the other end of the second leg 101b. The measured current I flows in opposite directions through the first leg 101a and the second leg 101b.

[0027] The Hall sensor 102 includes a first Hall sensor unit 102a and a second Hall sensor unit 102b. The first Hall sensor unit 102a and the second Hall sensor unit 102b are located around the conductor 101 to form a differential output. Figure 1 In the specific embodiment shown, the first Hall sensor unit 102a and the second Hall sensor unit 102b are respectively located on the front side (which is the side where the first leg 101a and the second leg 101b are located) and the rear side (which is the side opposite to the side where the first leg 101a and the second leg 101b are located) of the connecting portion 101c of the U-shaped conductor 101, and the first Hall sensor unit 102a and the second Hall sensor unit 102b are close to one end of the connecting portion 101c of the U-shaped conductor 101 (which is connected to the first leg 101a).

[0028] The planar coil sensor 103 includes a first planar coil sensor unit 103a and a second planar coil sensor unit 103b. The first planar coil sensor unit 103a and the second planar coil sensor unit 103b are located around the conductor 101 to form a differential output. Figure 1 In the specific embodiment shown, the first planar coil sensor unit 103a and the second planar coil sensor unit 103b are respectively located on the front side (which is the side where the first leg 101a and the second leg 101b are located) and the rear side (which is the side opposite to the side where the first leg 101a and the second leg 101b are located) of the connecting portion 101c of the U-shaped conductor 101, and the first planar coil sensor unit 103a and the second planar coil sensor unit 103b are close to the other end of the connecting portion 101c of the U-shaped conductor 101 (which is connected to the second leg 101b).

[0029] For the sake of convenience, the first Hall sensor unit 102a and the second Hall sensor unit 102b are collectively referred to as Hall sensor units 102a and 102b; the first planar coil sensor unit 103a and the second planar coil sensor unit 103b are collectively referred to as planar coil sensor units 103a and 103b. Figure 4 As shown, it is Figure 1 FIG. 1 is a schematic circuit diagram of the Hall sensor units 102 a and 102 b and the planar coil sensor units 103 a and 103 b in one embodiment.

[0030] Figure 4 The Hall sensor units 102a and 102b shown are conventional designs in the prior art and will not be described in detail here.

[0031] Figure 4 The planar coil sensor units 103a and 103b shown include a planar coil 104, a differential amplifier 105, and an integration circuit 107. The two ports of the planar coil 104 are respectively connected to the two input terminals of the differential amplifier 105. The differential amplifier 105 is configured to amplify the difference between the voltages at its two input terminals and output the amplified differential voltage through its output terminal. The input terminal of the integration circuit 107 is connected to the output terminal of the differential amplifier 105, and the output terminal of the integration circuit 107 is connected to the output terminals of the planar coil sensor units 103a and 103b. The output signal of the integration circuit 107 is proportional to the time-integrated value of the input signal at its input terminal.

[0032] exist Figure 4In the embodiment shown, the integration circuit 107 includes an operational amplifier 106, an integration resistor R, and an integration capacitor C. The first input terminal of the operational discharger 106 is connected to the output terminal of the differential amplifier 105 via the integration resistor R, and the first input terminal thereof is connected to the output terminal of the differential amplifier 105 via the integration capacitor C, and the second input terminal thereof is grounded. Figure 4 In the embodiment shown, the first input terminal and the second input terminal of the operational amplifier 106 are the inverting input terminal and the non-inverting input terminal thereof, respectively. It should be noted that the integration circuit 107 may also be other types of integration circuits in the prior art.

[0033] Please refer to Figure 2 As shown, it is along Figure 1 Schematic diagram of the cross section of the AA section line. Figure 2 It can be seen that the measured current I generates a magnetic field H in the first Hall sensor unit 102a. 11 , a magnetic field -H is generated in the second Hall sensor unit 102b 12 The output of the first Hall sensor unit 102a is V 11 =(H 11 I+H0)S, where H0 is the external magnetic field and S is the sensitivity of the Hall sensor to the magnetic field; the output of the second Hall sensor unit 102b is V 12 =(-H 12 I+H0)S; the output of the Hall sensor 102 is V 11 -V 12 =(H 11 +H 12 The Hall sensor 102 is used to detect low-frequency current.

[0034] Please refer to Figure 3 As shown, it is along Figure 1 Schematic diagram of the cross section of the BB section line. Figure 3 It can be seen that the measured current I generates a magnetic field H in the first planar coil sensor unit 103a. 21 , a magnetic field -H is generated in the second planar coil sensor unit 103b 22 The output of the first planar coil sensor unit 103a is V 21 =μ0A eff (H 21 I+H0) / (RC), where μ0 is the vacuum permeability, A eff is the effective area surrounded by the planar coil 104, R is the resistance value of the integrating resistor R of the integrating circuit 107, and C is the capacitance value of the integrating capacitor C of the integrating circuit 107; the output of the second planar coil sensor unit 103b is V 22 =μ0A eff (-H 22I+H0) / (RC); the output of the planar coil sensor 103 is V 21 -V 22 =μ0A eff (H 21 +H 22 )I / (RC). The planar coil sensor 103 is used to detect high-frequency current.

[0035] In summary, Figure 1 The technical advantages of the full-band current sensor shown are: on the one hand, it can effectively eliminate the influence of the external magnetic field, thereby improving the current detection accuracy; on the other hand, it can realize full-band current detection.

[0036] In the present invention, words such as “connect,” “connected,” “connect,” and “connected” that represent electrical connection, unless otherwise specified, represent direct or indirect electrical connection.

[0037] The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiment. Any equivalent modifications or changes made by ordinary technicians in this field based on the content disclosed in the present invention should be included in the protection scope recorded in the claims.

Claims

1. A full-band current sensor, which detects the measured current based on the magnetic induction intensity generated by the measured current, characterized in that: It includes a conductor, a Hall sensor and a planar coil sensor. The conductor is used to provide a passage for the measured current to flow through, so that the measured current can flow through the conductor; The Hall sensor is located around the conductor and is used to detect the low-frequency current in the measured current; The planar coil sensor is located around the conductor and is used to detect high-frequency current in the measured current. The Hall sensor includes a first Hall sensor unit and a second Hall sensor unit. The first Hall sensor unit and the second Hall sensor unit are located around the conductor to form a differential output, The planar coil sensor includes a first planar coil sensor unit and a second planar coil sensor unit. The first planar coil sensor unit and the second planar coil sensor unit are located around the conductor to form a differential output. The conductor is a U-shaped conductor, comprising a first leg, a second leg, and a connecting portion connecting the first leg and the second leg. The first leg and the second leg are located on the same side of the connecting portion; The directions of the measured currents flowing through the first leg and the second leg are opposite, The first Hall sensor unit and the second Hall sensor unit are respectively located at the front side and the rear side of the connecting portion of the conductor; The first planar coil sensor unit and the second planar coil sensor unit are respectively located at the front side and the rear side of the connection portion of the conductor.

2. The current sensor according to claim 1, wherein The first planar coil sensor unit and the second planar coil sensor unit are collectively referred to as a planar coil sensor unit. The planar coil sensor unit includes a planar coil, a differential amplifier, and an integration circuit. The two ports of the planar coil are respectively connected to the two input terminals of the differential amplifier; The differential amplifier is used to amplify the difference between the voltages of its two input terminals and output the amplified difference voltage through its output terminal; The input end of the integration circuit is connected to the output end of the differential amplifier, and the output end of the integration circuit is connected to the output end of the planar coil sensor unit. The output signal of the integration circuit is proportional to the time integral value of the input signal of the integration circuit.

3. The current sensor according to claim 2, characterized in that The planar coil sensor unit includes an operational amplifier, an integrating resistor and an integrating capacitor. The first input terminal of the operational amplifier is connected to the output terminal of the differential amplifier via an integrating resistor, and the first input terminal thereof is connected to the output terminal thereof via an integrating capacitor, and the second input terminal thereof is grounded.

4. The current sensor according to claim 3, characterized in that The first input terminal and the second input terminal of the operational amplifier are respectively the inverting input terminal and the non-inverting input terminal thereof.

5. The current sensor according to claim 1, wherein The output of the first planar coil sensor unit is V 21 =μ0A eff (H 21 I+H0) / (RC); The output of the second planar coil sensor unit is V 22 =μ0A eff (-H 22 I+H0) / (RC); The output of the planar coil sensor is V 21 -V 22 =μ0A eff (H 21 +H 22 )I / (RC), Where μ0 is the vacuum permeability, A eff is the effective area surrounded by the planar coil, R is the resistance value of the integral resistor, C is the capacitance value of the integral capacitor, H0 is the external magnetic field, and the measured current I generates a magnetic field H in the first planar coil sensor unit. 21 , the second planar coil sensor unit generates a magnetic field -H 22 .

6. The current sensor according to claim 1, wherein: The Hall sensor and the planar coil sensor are integrated on the same chip.

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