A hall array applied to a three-axis magnetic sensing chip and a control method thereof

Abstract

The application discloses a Hall array applied to a three-axis magnetic sensing chip and a control method thereof, which comprises a magnet collector disc and eight horizontal Hall discs, the eight horizontal Hall discs are divided into four groups of Hall discs and are distributed at equal intervals on the edge of the magnet collector disc, and the four groups of Hall discs are symmetrically distributed on the magnet collector disc in the up-down and left-right directions. Through the cooperative design of the eight Hall array+IMC+specific time sequence control, high-precision measurement of a three-axis magnetic field is realized.

Description

Technical Field

[0001] This invention relates to a Hall array and its control method, particularly a Hall array and its control method applied to a triaxial magnetic sensing chip, belonging to the field of semiconductor integrated circuit technology. Background Technology

[0002] Magnetic sensors, as key sensing elements, are widely used in automobiles, consumer electronics, and medical devices. Among them, Hall effect sensors hold a significant market share due to their low cost, high stability, wide measurement range, and good compatibility with CMOS processes. In modern integrated magnetic sensing systems, triaxial Hall effect magnetic sensors are widely used in electronic compasses, attitude detection, and brushless motor control because they can simultaneously acquire the direction and intensity of the magnetic field vector.

[0003] Traditional Hall sensors typically employ a horizontal Hall plate structure, with its sensing direction perpendicular to the chip surface (i.e., the Z-axis). Therefore, they inherently cannot directly detect magnetic field components (Bx, By) parallel to the chip plane. To achieve triaxial magnetic field vector measurement, early solutions often relied on physically orthogonally arranging three Hall plates (e.g., placing them on the three faces of a non-magnetic cube); or combining horizontal and vertical Hall plates to sense the Z-axis and X / Y axes respectively. However, these solutions have significant limitations: orthogonal stacked structures are difficult to integrate monolithically, resulting in high manufacturing complexity; while vertical Hall plates require special processes (such as deep wells or high-energy injection), have poor compatibility with standard CMOS processes, and exhibit lower sensitivity and higher noise.

[0004] In recent years, Integrated Magnetic Concentrator (IMC) technology has provided a revolutionary solution for triaxial Hall sensors. IMCs are typically composed of high permeability (relative permeability μ). r It is composed of a soft magnetic thin film with low coercivity (>10000) and is integrated on top of a Hall plate. Its core physical mechanism lies in the fact that the magnetic field lines of an external parallel magnetic field (Bx or By) are highly concentrated by the IMC and bent at its edges, thereby generating a significantly enhanced vertical magnetic field component (Bz) in a localized region. Figure 6 As shown. This effect enables the parallel magnetic field, which would otherwise be undetectable by the horizontal Hall plate, to be efficiently converted and amplified into a vertical component Bz at the edge of the IMC, thus allowing it to be directly detected by the horizontal Hall plate below.

[0005] like Figure 7As shown, a typical triaxial Hall sensor based on an IMC requires only four coplanar horizontal Hall disks (labeled X1, X2, Y1, Y2) and a circular IMC to achieve full-vector magnetic field measurement. Through a reasonable layout (Hall disks symmetrically distributed along the edge of the circular IMC), the following can be achieved: The magnetic field in the X direction produces an enhanced vertical field B with opposite polarity at X1 / X2. x ; The magnetic field in the Y direction produces an enhanced vertical field B with opposite polarity at Y1 / Y2. y ; The magnetic field in the Z direction is directly sensed by all Hall plates, and is less affected by IMC, with an amplification factor of approximately 1.

[0006] Based on this, the three-dimensional magnetic field components can be decoupled by performing subtraction and summation operations on the outputs of the four Hall disks. This scheme can reconstruct arbitrary three-dimensional magnetic field vectors and uses only a horizontal Hall structure compatible with standard CMOS technology, which greatly simplifies the manufacturing process and reduces costs.

[0007] Although this four-Hall disk structure has advantages in terms of area and process compatibility, it still has the following technical limitations in practical applications: 1. Single Hall pair structure is susceptible to process and environmental disturbances: The measurement of magnetic field in each direction (such as the X-axis) relies on only a single Hall pair (X1~X2). When encountering manufacturing mismatch, local wafer stress or temperature gradient, the Hall output voltage error is large, which directly affects the accuracy of magnetic field measurement. 2. Limited noise suppression capability: Due to the small number of Hall plates, the output signal is not processed by multi-source averaging. Thermal noise and 1 / f noise are directly superimposed on the final result, which limits the signal-to-noise ratio (SNR) and weak field detection capability. 3. Back-end amplifier offset and 1 / f noise are not effectively suppressed: Existing solutions usually use ordinary instrumentation amplifiers or differential amplifiers to read the Hall signal. The input offset voltage and 1 / f noise that exist in these amplifiers will directly affect the measurement of the weak Hall voltage. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a Hall array and its control method for a triaxial magnetic sensing chip, which breaks through the limitations of the traditional four-Hall scheme in terms of accuracy, robustness and noise performance.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A Hall array for use in a triaxial magnetic sensing chip includes a magnet collector disk and eight horizontal Hall disks. The eight horizontal Hall disks are divided into four groups of Hall disks and are distributed at equal intervals on the edge of the magnet collector disk. The four groups of Hall disks are symmetrically distributed on the magnet collector disk in all directions.

[0010] Furthermore, the magnet collector disk is made of a circular soft magnetic film.

[0011] Furthermore, the circular soft magnetic thin film employs a relative permeability μ r >10000, low coercivity permalloy.

[0012] Furthermore, the horizontal Hall effect sensor includes a Hall element H1, an enable control switch SW0, an enable control switch SW1, and a chopper switch CH1. The C terminal of the Hall element H1 is connected to one end of the enable control switch SW0, and the other end of the enable control switch SW0 is connected to the power supply VCC. The A terminal of the Hall element H1 is connected to one end of the enable control switch SW1, and the other end of the enable control switch SW1 is grounded. The D terminal of the Hall element H1 is connected to the positive input terminal of the chopper switch CH1, and the B terminal of the Hall element H1 is connected to the negative input terminal of the chopper switch CH1. The positive output terminal of the chopper switch CH1 serves as the positive output terminal of the horizontal Hall element, and the negative output terminal of the chopper switch CH1 serves as the negative output terminal of the horizontal Hall element. The enable control switches SW0 and SW1 are controlled by the enable signal EN.

[0013] Furthermore, the chopper switch CH1 includes switches SW2, SW3, SW4, and SW5. One end of switch SW2 is connected to one end of switch SW5 and serves as the positive input terminal of chopper switch CH1. One end of switch SW4 is connected to one end of switch SW3 and serves as the negative input terminal of chopper switch CH1. The other end of switch SW2 is connected to the other end of switch SW4 and serves as the positive output terminal of chopper switch CH1. The other end of switch SW5 is connected to the other end of switch SW3 and serves as the negative output terminal of chopper switch CH1. Switches SW2 and SW3 are controlled by control signal POL, and switches SW4 and SW5 are controlled by control signal POL_B. Control signals POL and POL_B are a set of inverted signals.

[0014] Furthermore, the eight horizontal Hall disks include horizontal Hall disk X1, horizontal Hall disk X2, horizontal Hall disk X3, horizontal Hall disk X4, horizontal Hall disk Y1, horizontal Hall disk Y2, horizontal Hall disk Y3, and horizontal Hall disk Y4. Horizontal Hall disk X1 and horizontal Hall disk X2 form one group, horizontal Hall disk X3 and horizontal Hall disk X4 form another group, horizontal Hall disk Y1 and horizontal Hall disk Y2 form another group, and horizontal Hall disk Y3 and horizontal Hall disk Y4 form another group. Horizontal Hall disk X1, horizontal Hall disk X2, horizontal Hall disk X3, and horizontal Hall disk X4 are symmetrically distributed on the left and right sides of the edge of the magnet collector disk, and horizontal Hall disk Y1, horizontal Hall disk Y2, horizontal Hall disk Y3, and horizontal Hall disk Y4 are symmetrically distributed on the top and bottom sides of the edge of the magnet collector disk.

[0015] Furthermore, the positive-phase output terminals of the horizontal Hall effect disks X1, X3, Y1, and Y3 are connected to the first positive-phase input terminal of the differential amplifier DDA; the negative-phase output terminals of the horizontal Hall effect disks X1, X3, Y1, and Y3 are connected to the first negative-phase input terminal of the differential amplifier DDA; the positive-phase output terminals of the horizontal Hall effect disks X2, X4, Y2, and Y4 are connected to the second positive-phase input terminal of the differential amplifier DDA; the negative-phase output terminals of the horizontal Hall effect disks X2, X4, Y2, and Y4 are connected to the second negative-phase input terminal of the differential amplifier DDA; the positive-phase output terminal of the differential amplifier DDA is connected to the positive-phase input terminal of the chopper switch CH_DDA; and the negative-phase output terminal of the differential amplifier DDA is connected to the negative-phase input terminal of the chopper switch CH_DDA.

[0016] A control method for a Hall array applied to a triaxial magnetic sensing chip includes the following steps: At positions X1 and X2 of the horizontal Hall disk, there exists a magnetic field B derived from the Z-axis component of the magnetic field B. z The direction is positive along the Z-axis; there exists a magnetic field B derived from the X-axis component of the magnetic field. x The direction is the positive Z-axis; At positions X3 and X4 of the horizontal Hall disk, there exists a magnetic field B derived from the Z-axis component of the magnetic field B. z The direction is positive along the Z-axis; there exists a magnetic field B derived from the X-axis component of the magnetic field. x The direction is the negative Z-axis; At positions Y1 and Y2 of the horizontal Hall disk, there exists a magnetic field B derived from the Z-axis component of the magnetic field B. z The direction is positive Z-axis; there exists a magnetic field B derived from the Y-axis component of the magnetic field. y The direction is the negative Z-axis; At positions Y3 and Y4 of the horizontal Hall disk, there exists a magnetic field B derived from the Z-axis component of the magnetic field B. z The direction is positive Z-axis; there exists a magnetic field B derived from the Y-axis component of the magnetic field. y The direction is the positive Z-axis; The magnitudes of the vertical magnetic field derived from the triaxial magnetic field components are as follows: (1) (2) (3) Among them, B x B y B zThese are the vertical magnetic fields derived from the X / Y / Z axis components of magnetic field B through IMC conversion, and C. xy C is the conversion coefficient of the IMC to the parallel magnetic field. z denoted as IMC conversion coefficient for the vertical magnetic field, B is the external magnetic field to be measured, θ is the inclination angle between magnetic field B and the XY plane, and α is the inclination angle between the projection of magnetic field B on the XY plane and the X-axis. Based on the magnitude and direction of the magnetic field of the different horizontal Hall disks, the outputs of the eight horizontal Hall disks can be obtained as follows: (4) (5) (6) (7) in, S v The voltage sensitivity of the Hall effect sensor. V bias This is the bias voltage of the Hall effect sensor. Let the gain of the differential amplifier DDA be A, then we can obtain: (8) Where V1 is the voltage between the first positive input terminal and the first negative input terminal of the differential amplifier DDA, V2 is the voltage between the second positive input terminal and the second negative input terminal of the differential amplifier DDA, and Vdda is the voltage between the positive output terminal and the negative output terminal of the differential amplifier DDA. PH_X phase: Horizontal Hall effect disks X1~X4 are turned on, and horizontal Hall effect disks Y1~Y4 are turned off; the output polarity of horizontal Hall effect disks X1 and X2 is in PH_X phase. φ0 The phase is positive, in PH_X φ1 The phase is negative; the output polarity of horizontal Hall plates X3 and X4 is in PH_X φ0 The phase is negative, in PH_X φ1 The phase is positive; the output polarity of the differential amplifier DDA is at PH_X. φ0 The phase is positive, in PH_X φ1 The phase is negative; let the offset of the differential amplifier DDA be Vos, then PH_X is obtained. φ0 and PH_X φ1 The outputs of the staged differential amplifier DDA are as follows: (9) (10) Averaging the outputs of the two phases yields the voltage proportional to the X-axis component of the magnetic field. (11) PH_Y phase: Horizontal Hall effect disks Y1~Y4 are turned on, and horizontal Hall effect disks X1~X4 are turned off; the output polarity of horizontal Hall effect disks Y1 and Y2 is in PH_Y phase. φ0 The phase is negative, in PH_Y φ1 The phase is positive; the output polarity of horizontal Hall plates Y3 and Y4 is in PH_Y φ0 The phase is positive, in PH_Y φ1 The phase is negative; the output polarity of the differential amplifier DDA is at PH_Y φ0 The phase is positive, in PH_Y φ1 The stage is negative; therefore, PH_Y can be obtained. φ0 and PH_Y φ1 The outputs of the staged differential amplifier DDA are as follows: (12) (13) Averaging the outputs of the two phases yields the voltage output proportional to the Y-axis component of the magnetic field. (14) In the PH_Z phase: the outputs of horizontal Hall effect disks X1~X4 are positive, and the outputs of horizontal Hall effect disks Y1~Y4 are negative; in PH_Z φ0 During this phase, horizontal Hall effect sensors X1~X4 are turned on, and horizontal Hall effect sensors Y1~Y4 are turned off; in PH_Z φ1 During this phase, horizontal Hall effect disks Y1~Y4 are turned on, and horizontal Hall effect disks X1~X4 are turned off; the output polarity of the differential amplifier DDA is at PH_Z. φ0 The phase is positive, in PH_Z φ1 The phase is negative; therefore, PH_Z can be obtained. φ0 and PH_Z φ1 The outputs of the staged differential amplifier DDA are as follows: (15) (16) Averaging the outputs of the two phases yields the voltage output proportional to the Z-axis component of the magnetic field. (17) Therefore, the three-axis magnetic field components are obtained according to formulas (11), (14), and (17), and the magnitude and direction of the external magnetic field B to be measured can be restored by combining formulas (1), (2), and (3).

[0017] Compared with the prior art, the present invention has the following advantages and effects: 1. While maintaining the advantages of CMOS process compatibility and IMC planar integration, this invention breaks through the limitations of traditional four-Hall schemes in terms of accuracy, robustness and noise performance by expanding Hall array, fusing multi-channel signals and controlling specific timing. It provides a new solution for high-performance triaxial magnetic sensing with high signal-to-noise ratio, low drift and strong environmental adaptability. 2. By configuring two sets of symmetrically distributed Hall disks for each magnetic field direction, the present invention enables the system to effectively suppress system errors caused by manufacturing mismatch, local stress or temperature gradient through signal fusion mechanism, thereby improving the robustness of triaxial magnetic field decoupling. 3. This invention increases the number of Hall plates and performs weighted averaging or summation on multiple sets of Hall outputs in the same direction, so that random noise is attenuated in a 1 / √N pattern (N is the number of effective channels), thereby improving the overall signal-to-noise ratio and the sensitivity of weak magnetic field detection. 4. This invention designs a differential amplifier (DDA) output chopping mechanism and deeply couples it with the control timing of the Hall effect disk: while reversing the Hall output polarity in a specific phase, the output chopping clock of the DDA is switched synchronously, so that the DDA offset is modulated to a high frequency and significantly attenuated after low-pass filtering, thereby achieving full-link noise suppression from the front end to the back end and significantly improving measurement accuracy. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a Hall array applied to a triaxial magnetic sensing chip according to the present invention.

[0019] Figure 2 This is a schematic diagram of the circuit structure of the horizontal Hall effect disk of the present invention.

[0020] Figure 3 This is a schematic diagram of the circuit structure of the chopper switch of the present invention.

[0021] Figure 4 This is a schematic diagram of the circuit connection of the Hall effect sensor of the present invention.

[0022] Figure 5 This is the timing diagram for Hall array control and DDA chopping of the present invention.

[0023] Figure 6 This is a schematic diagram of the magnetizing effect of existing IMC technology.

[0024] Figure 7 This is a schematic diagram of a triaxial Hall sensor structure based on IMC in the existing technology. Detailed Implementation

[0025] To illustrate in detail the technical solutions adopted by the present invention to achieve the intended technical objectives, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Furthermore, the technical means or technical features in the embodiments of the present invention can be replaced without creative effort. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0026] like Figure 1 As shown, a Hall array for a triaxial magnetic sensing chip according to the present invention includes a magnet collector disk IMC and eight horizontal Hall disks. The eight horizontal Hall disks are divided into four groups of Hall disks and are distributed at equal intervals on the edge of the magnet collector disk IMC. The four groups of Hall disks are symmetrically distributed on the magnet collector disk IMC in all directions.

[0027] The magnet collector disk IMC uses a circular soft magnetic thin film. The circular soft magnetic thin film has a relative permeability μ... r >10000, low coercivity permalloy. Its function is to efficiently convert the parallel component of the external magnetic field B to be measured into the perpendicular component at the edge, while simultaneously enhancing the magnetic field.

[0028] like Figure 2 As shown, the horizontal Hall effect sensor includes a Hall element H1, an enable control switch SW0, an enable control switch SW1, and a chopper switch CH1. Terminal C of Hall element H1 is connected to one end of enable control switch SW0, and the other end of enable control switch SW0 is connected to the power supply VCC. Terminal A of Hall element H1 is connected to one end of enable control switch SW1, and the other end of enable control switch SW1 is grounded. Terminal D of Hall element H1 is connected to the positive input terminal of chopper switch CH1, and terminal B of Hall element H1 is connected to the negative input terminal of chopper switch CH1. The positive output terminal of chopper switch CH1 serves as the positive output terminal of the horizontal Hall effect sensor, and the negative output terminal of chopper switch CH1 serves as the negative output terminal of the horizontal Hall effect sensor. Enable control switches SW0 and SW1 are controlled by an enable signal EN. When the enable signal EN is high, enable control switches SW0 and SW1 are turned on, and the horizontal Hall effect sensor operates normally. When the enable signal EN is low, enable control switches SW0 and SW1 are turned off, and the horizontal Hall effect sensor does not operate. The voltage difference between terminals A and C of Hall element H1 is the bias voltage V. bias The differential output signal Vhall between terminals B and D of Hall element H1 is proportional to the magnitude of the applied vertical magnetic field. The signal Vhall is then passed through chopper switch CH1 to obtain the output signal Vo.

[0029] like Figure 3As shown, the chopper switch CH1 includes switches SW2, SW3, SW4, and SW5. One end of switch SW2 is connected to one end of switch SW5 and serves as the positive input terminal of chopper switch CH1. One end of switch SW4 is connected to one end of switch SW3 and serves as the negative input terminal of chopper switch CH1. The other end of switch SW2 is connected to the other end of switch SW4 and serves as the positive output terminal of chopper switch CH1. The other end of switch SW5 is connected to the other end of switch SW3 and serves as the negative output terminal of chopper switch CH1. Switches SW2 and SW3 are controlled by control signal POL, and switches SW4 and SW5 are controlled by control signal POL_B. Control signals POL and POL_B are a pair of inverted signals. When control signal POL is high, Vo = Vhall; when POL is low, Vo = -Vhall.

[0030] All eight horizontal Hall effect sensors use the same circuit topology, but differentiated operation is achieved through different enable signals EN and control signals POL.

[0031] The eight horizontal Hall effect disks include horizontal Hall effect disk X1, horizontal Hall effect disk X2, horizontal Hall effect disk X3, horizontal Hall effect disk X4, horizontal Hall effect disk Y1, horizontal Hall effect disk Y2, horizontal Hall effect disk Y3, and horizontal Hall effect disk Y4. Horizontal Hall effect disks X1 and X2 form one group, horizontal Hall effect disks X3 and X4 form another group, horizontal Hall effect disks Y1 and Y2 form another group, and horizontal Hall effect disks Y3 and Y4 form another group. Horizontal Hall effect disks X1, X2, X3, and X4 are symmetrically distributed on the left and right sides of the edge of the magnet collector disk, while horizontal Hall effect disks Y1, Y2, Y3, and Y4 are symmetrically distributed on the top and bottom of the edge of the magnet collector disk.

[0032] The positive-phase output terminals of horizontal Hall effect disks X1, X3, Y1, and Y3 are connected to the first positive-phase input terminal of the differential amplifier DDA. The negative-phase output terminals of horizontal Hall effect disks X1, X3, Y1, and Y3 are connected to the first negative-phase input terminal of the differential amplifier DDA. The positive-phase output terminals of horizontal Hall effect disks X2, X4, Y2, and Y4 are connected to the second positive-phase input terminal of the differential amplifier DDA. The negative-phase output terminals of horizontal Hall effect disks X2, X4, Y2, and Y4 are connected to the second negative-phase input terminal of the differential amplifier DDA. The positive-phase output terminal of the differential amplifier DDA is connected to the positive-phase input terminal of the chopper switch CH_DDA. The negative-phase output terminal of the differential amplifier DDA is connected to the negative-phase input terminal of the chopper switch CH_DDA.

[0033] Eight Hall effect sensors are connected in parallel in two groups for differential connection, and finally connected to a differential amplifier (DDA) to achieve high-precision, low-noise triaxial magnetic field signal extraction. The bias terminals of all Hall effect sensors are connected to the same power rail to ensure power supply consistency. The operating state of each Hall element is controlled by independent enable control signals (EN_Xi, EN_Yi) to achieve on-demand activation and deactivation. Simultaneously, the polarity of the corresponding Hall effect sensor output terminal can be dynamically switched via polarity control signals (POL_Xi, POL_Yi) to support summation or difference operations. The reference ground terminals of all Hall effect sensors are connected to the same grounding node to ensure a unified reference potential for the system, improving signal common-mode rejection and measurement stability.

[0034] A chopper switch CH_DDA is added to the output stage of the differential amplifier DDA. The polarity of the final output signal VOUT can be controlled by the signal POL_DDA. When the signal POL_DDA is high, VOUT = Vdda; when the signal POL_DDA is low, VOUT = -Vdda. The output chopper, combined with a specific Hall effect control timing, can further reduce the offset of the differential amplifier DDA and the error caused by 1 / f noise.

[0035] The differential amplifier (DDA) features a high common-mode rejection ratio (CMRR), effectively suppressing common-mode noise introduced by power supply fluctuations and substrate coupling. The differential signal VOUT output by the DDA can be used for subsequent ADC sampling or directly driving analog interfaces.

[0036] A control method for a Hall array applied to a triaxial magnetic sensing chip includes the following steps: When the external magnetic field B to be measured is incident at inclination angles α and θ, the vertical magnetic field generated at each position on the edge of the IMC is composed of the superposition of two magnetic fields. The specific magnitude and direction of the magnetic field are as follows: At positions X1 and X2 of the horizontal Hall disk, there exists a magnetic field B derived from the Z-axis component of the magnetic field B. z The direction is positive along the Z-axis; there exists a magnetic field B derived from the X-axis component of the magnetic field. x The direction is the positive Z-axis; At positions X3 and X4 of the horizontal Hall disk, there exists a magnetic field B derived from the Z-axis component of the magnetic field B. z The direction is positive along the Z-axis; there exists a magnetic field B derived from the X-axis component of the magnetic field. x The direction is the negative Z-axis; At positions Y1 and Y2 of the horizontal Hall disk, there exists a magnetic field B derived from the Z-axis component of the magnetic field B. z The direction is positive Z-axis; there exists a magnetic field B derived from the Y-axis component of the magnetic field.y The direction is the negative Z-axis; At positions Y3 and Y4 of the horizontal Hall disk, there exists a magnetic field B derived from the Z-axis component of the magnetic field B. z The direction is positive Z-axis; there exists a magnetic field B derived from the Y-axis component of the magnetic field. y The direction is the positive Z-axis; The magnitudes of the vertical magnetic field derived from the triaxial magnetic field components are as follows: (1) (2) (3) Among them, B x B y B z These are the vertical magnetic fields derived from the X / Y / Z axis components of magnetic field B through IMC conversion, and C. xy C is the conversion coefficient of the IMC to the parallel magnetic field. z Let θ be the conversion coefficient of the IMC to the vertical magnetic field, B be the external magnetic field to be measured, θ be the tilt angle between the magnetic field B and the XY plane, and α be the tilt angle between the projection of the magnetic field B on the XY plane and the X-axis.

[0037] Based on the magnitude and direction of the magnetic field of the different horizontal Hall disks, the outputs of the eight horizontal Hall disks can be obtained as follows: (4) (5) (6) (7) in, S v The voltage sensitivity of the Hall effect sensor. V bias This is the bias voltage of the Hall effect sensor.

[0038] Let the gain of the differential amplifier DDA be A, then we can obtain: (8) Where V1 is the voltage between the first positive input terminal and the first negative input terminal of the differential amplifier DDA, V2 is the voltage between the second positive input terminal and the second negative input terminal of the differential amplifier DDA, and Vdda is the voltage between the positive output terminal and the negative output terminal of the differential amplifier DDA.

[0039] like Figure 5As shown, the overall working process is divided into three working stages, which correspond to the measurement of magnetic fields in three different directions. At the same time, each working stage has two phases φ0 and φ1.

[0040] PH_X phase: Horizontal Hall effect disks X1~X4 are turned on, and horizontal Hall effect disks Y1~Y4 are turned off; the output polarity of horizontal Hall effect disks X1 and X2 is in PH_X phase. φ0 The phase is positive, in PH_X φ1 The phase is negative; the output polarity of horizontal Hall plates X3 and X4 is in PH_X φ0 The phase is negative, in PH_X φ1 The phase is positive; the output polarity of the differential amplifier DDA is at PH_X. φ0 The phase is positive, in PH_X φ1 The phase is negative; let the offset of the differential amplifier DDA be Vos, then PH_X is obtained. φ0 and PH_X φ1 The outputs of the staged differential amplifier DDA are as follows: (9) (10) Averaging the outputs of the two phases yields the voltage proportional to the X-axis component of the magnetic field. (11).

[0041] PH_Y phase: Horizontal Hall effect disks Y1~Y4 are turned on, and horizontal Hall effect disks X1~X4 are turned off; the output polarity of horizontal Hall effect disks Y1 and Y2 is in PH_Y phase. φ0 The phase is negative, in PH_Y φ1 The phase is positive; the output polarity of horizontal Hall plates Y3 and Y4 is in PH_Y φ0 The phase is positive, in PH_Y φ1 The phase is negative; the output polarity of the differential amplifier DDA is at PH_Y φ0 The phase is positive, in PH_Y φ1 The stage is negative; therefore, PH_Y can be obtained. φ0 and PH_Y φ1 The outputs of the staged differential amplifier DDA are as follows: (12) (13) Averaging the outputs of the two phases yields the voltage output proportional to the Y-axis component of the magnetic field. (14).

[0042] In the PH_Z phase: the outputs of horizontal Hall effect disks X1~X4 are positive, and the outputs of horizontal Hall effect disks Y1~Y4 are negative; in PH_Z φ0 During this phase, horizontal Hall effect sensors X1~X4 are turned on, and horizontal Hall effect sensors Y1~Y4 are turned off; in PH_Z φ1 During this phase, horizontal Hall effect disks Y1~Y4 are turned on, and horizontal Hall effect disks X1~X4 are turned off; the output polarity of the differential amplifier DDA is at PH_Z. φ0 The phase is positive, in PH_Z φ1 The phase is negative; therefore, PH_Z can be obtained. φ0 and PH_Z φ1 The outputs of the staged differential amplifier DDA are as follows: (15) (16) Averaging the outputs of the two phases yields the voltage output proportional to the Z-axis component of the magnetic field. (17).

[0043] Therefore, the three-axis magnetic field components are obtained according to formulas (11), (14), and (17), and the formulas do not contain the offset voltage Vos of the differential amplifier DDA, thus reducing the error caused by it. Combined with formulas (1), (2), and (3), the magnitude and direction of the external magnetic field B to be measured can be reconstructed. This invention achieves high-precision measurement of the three-axis magnetic field through the collaborative design of an eight-Hall array + IMC + specific timing control.

[0044] This invention, while maintaining the advantages of CMOS process compatibility and IMC planar integration, overcomes the limitations of traditional four-Hall schemes in terms of accuracy, robustness, and noise performance through Hall array expansion, multi-channel signal fusion, and specific timing control. It provides a novel solution for high-performance triaxial magnetic sensing with high signal-to-noise ratio, low drift, and strong environmental adaptability. When measuring the magnetic field in each direction, this invention employs two sets of symmetrically distributed Hall disks, which can reduce the impact of manufacturing mismatch, local stress, or temperature gradients. By increasing the number of Hall disks and using multiple sets of Hall outputs for averaging, noise can be reduced and the signal-to-noise ratio improved. The differential amplifier (DDA) output chopping, combined with specific Hall disk control timing, can reduce errors caused by DDA offset and 1 / f noise, thereby improving measurement accuracy.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A control method for a Hall array applied to a triaxial magnetic sensing chip, wherein the Hall array applied to the triaxial magnetic sensing chip comprises a magnet collector disk and eight horizontal Hall disks, the eight horizontal Hall disks are each divided into four groups of Hall disks and are equally spaced on the edge of the magnet collector disk, the four groups of Hall disks are symmetrically distributed vertically and horizontally on the magnet collector disk; the eight horizontal Hall disks include horizontal Hall disk X1, horizontal Hall disk X2, horizontal Hall disk X3, horizontal Hall disk X4, horizontal Hall disk Y1, horizontal Hall disk Y2, horizontal Hall disk Y3 and horizontal Hall disk Y4, wherein horizontal Hall disk X1 and horizontal Hall disk X2 form one group, horizontal Hall disk X3 and horizontal Hall disk X4 form another group, horizontal Hall disk Y1 and horizontal Hall disk Y2 form another group, horizontal Hall disk Y3 and horizontal Hall disk Y4 form another group, horizontal Hall disk X1, horizontal Hall disk X2, horizontal Hall disk X3 and horizontal Hall disk X4 are symmetrically distributed horizontally on the edge of the magnet collector disk, and horizontal Hall disk Y1, horizontal Hall disk Y2, horizontal Hall disk Y3 and horizontal Hall disk Y4 are symmetrically distributed horizontally on the edge of the magnet collector disk, and horizontal Hall disk Y1, horizontal Hall disk Y2, horizontal Hall disk Y3 and horizontal Hall disk Y4 are symmetrically distributed horizontally on the edge of the magnet collector disk. Horizontal Hall effect disks Y4 are symmetrically distributed above and below the edge of the magnet collector disk; the positive phase output terminals of horizontal Hall effect disks X1, X3, Y1, and Y3 are connected to the first positive phase input terminal of the differential amplifier DDA, the negative phase output terminals of horizontal Hall effect disks X1, X3, Y1, and Y3 are connected to the first negative phase input terminal of the differential amplifier DDA, the positive phase output terminals of horizontal Hall effect disks X2, X4, Y2, and Y4 are connected to the second positive phase input terminal of the differential amplifier DDA, the negative phase output terminals of horizontal Hall effect disks X2, X4, Y2, and Y4 are connected to the second negative phase input terminal of the differential amplifier DDA, the positive phase output terminal of the differential amplifier DDA is connected to the positive phase input terminal of the chopper switch CH_DDA, and the negative phase output terminal of the differential amplifier DDA is connected to the negative phase input terminal of the chopper switch CH_DDA; Its features Includes the following steps: At positions X1 and X2 of the horizontal Hall disk, there exists a magnetic field B derived from the Z-axis component of the magnetic field B. z The direction is positive along the Z-axis; there exists a magnetic field B derived from the X-axis component of the magnetic field. x The direction is the positive Z-axis; At positions X3 and X4 of the horizontal Hall disk, there exists a magnetic field B derived from the Z-axis component of the magnetic field B. z The direction is positive along the Z-axis; there exists a magnetic field B derived from the X-axis component of the magnetic field. x The direction is the negative Z-axis; At positions Y1 and Y2 of the horizontal Hall disk, there exists a magnetic field B derived from the Z-axis component of the magnetic field B. z The direction is positive Z-axis; there exists a magnetic field B derived from the Y-axis component of the magnetic field. y The direction is the negative Z-axis; At positions Y3 and Y4 of the horizontal Hall disk, there exists a magnetic field B derived from the Z-axis component of the magnetic field B. z The direction is positive Z-axis; there exists a magnetic field B derived from the Y-axis component of the magnetic field. y The direction is the positive Z-axis; The magnitudes of the vertical magnetic field derived from the triaxial magnetic field components are as follows: （1） （2） （3） Among them, B x B y B z These are the vertical magnetic fields derived from the X / Y / Z axis components of magnetic field B through IMC conversion, and C. xy C is the conversion coefficient of the IMC to the parallel magnetic field. z denoted as IMC conversion coefficient for the vertical magnetic field, B is the external magnetic field to be measured, θ is the inclination angle between magnetic field B and the XY plane, and α is the inclination angle between the projection of magnetic field B on the XY plane and the X-axis. Based on the magnitude and direction of the magnetic field of the different horizontal Hall disks, the outputs of the eight horizontal Hall disks can be obtained as follows: （4） （5） （6） （7） in, S v The voltage sensitivity of the Hall effect sensor. V bias This is the bias voltage of the Hall effect sensor. Let the gain of the differential amplifier DDA be A, then we can obtain: （8） Where V1 is the voltage between the first positive input terminal and the first negative input terminal of the differential amplifier DDA, V2 is the voltage between the second positive input terminal and the second negative input terminal of the differential amplifier DDA, and Vdda is the voltage between the positive output terminal and the negative output terminal of the differential amplifier DDA. PH_X phase: Horizontal Hall effect disks X1~X4 are turned on, and horizontal Hall effect disks Y1~Y4 are turned off; the output polarity of horizontal Hall effect disks X1 and X2 is in PH_X phase. φ0 The phase is positive, in PH_X φ1 The phase is negative; the output polarity of horizontal Hall plates X3 and X4 is in PH_X φ0 The phase is negative, in PH_X φ1 The phase is positive; the output polarity of the differential amplifier DDA is at PH_X. φ0 The phase is positive, in PH_X φ1 The phase is negative; let the offset of the differential amplifier DDA be Vos, then PH_X is obtained. φ0 and PH_X φ1 The outputs of the staged differential amplifier DDA are as follows: （9） （10） Averaging the outputs of the two phases yields the voltage proportional to the X-axis component of the magnetic field. （11） PH_Y phase: Horizontal Hall effect disks Y1~Y4 are turned on, and horizontal Hall effect disks X1~X4 are turned off; the output polarity of horizontal Hall effect disks Y1 and Y2 is in PH_Y phase. φ0 The phase is negative, in PH_Y φ1 The phase is positive; the output polarity of horizontal Hall plates Y3 and Y4 is in PH_Y φ0 The phase is positive, in PH_Y φ1 The phase is negative; the output polarity of the differential amplifier DDA is at PH_Y φ0 The phase is positive, in PH_Y φ1 The phase is negative; therefore, PH_Y can be obtained. φ0 and PH_Y φ1 The outputs of the staged differential amplifier DDA are as follows: （12） （13） Averaging the outputs of the two phases yields the voltage output proportional to the Y-axis component of the magnetic field. （14） In the PH_Z phase: the outputs of horizontal Hall effect disks X1~X4 are positive, and the outputs of horizontal Hall effect disks Y1~Y4 are negative; in PH_Z φ0 During this phase, horizontal Hall effect sensors X1~X4 are turned on, and horizontal Hall effect sensors Y1~Y4 are turned off; in PH_Z φ1 During this phase, horizontal Hall effect disks Y1~Y4 are turned on, and horizontal Hall effect disks X1~X4 are turned off; the output polarity of the differential amplifier DDA is at PH_Z. φ0 The phase is positive, in PH_Z φ1 The stage is negative; therefore, PH_Z can be obtained. φ0 and PH_Z φ1 The outputs of the staged differential amplifier DDA are as follows: （15） （16） Averaging the outputs of the two phases yields the voltage output proportional to the Z-axis component of the magnetic field. （17） Therefore, the three-axis magnetic field components are obtained according to formulas (11), (14), and (17), and the magnitude and direction of the external magnetic field B to be measured can be restored by combining formulas (1), (2), and (3).

2. The control method according to claim 1, characterized in that: The magnet collector disk is made of a circular soft magnetic film.

3. The control method according to claim 2, characterized in that: The circular soft magnetic thin film has a relative magnetic permeability μ r >10000, low coercivity permalloy.

4. The control method according to claim 1, characterized in that: The horizontal Hall effect sensor includes a Hall element H1, an enable control switch SW0, an enable control switch SW1, and a chopper switch CH1. The C terminal of the Hall element H1 is connected to one end of the enable control switch SW0, and the other end of the enable control switch SW0 is connected to the power supply VCC. The A terminal of the Hall element H1 is connected to one end of the enable control switch SW1, and the other end of the enable control switch SW1 is grounded. The D terminal of the Hall element H1 is connected to the positive input terminal of the chopper switch CH1, and the B terminal of the Hall element H1 is connected to the negative input terminal of the chopper switch CH1. The positive output terminal of the chopper switch CH1 serves as the positive output terminal of the horizontal Hall element, and the negative output terminal of the chopper switch CH1 serves as the negative output terminal of the horizontal Hall element. The enable control switches SW0 and SW1 are controlled by the enable signal EN.

5. The control method according to claim 4, characterized in that: The chopper switch CH1 includes switches SW2, SW3, SW4, and SW5. One end of switch SW2 is connected to one end of switch SW5 and serves as the positive input terminal of chopper switch CH1. One end of switch SW4 is connected to one end of switch SW3 and serves as the negative input terminal of chopper switch CH1. The other end of switch SW2 is connected to the other end of switch SW4 and serves as the positive output terminal of chopper switch CH1. The other end of switch SW5 is connected to the other end of switch SW3 and serves as the negative output terminal of chopper switch CH1. Switches SW2 and SW3 are controlled by control signal POL, and switches SW4 and SW5 are controlled by control signal POL_B. Control signals POL and POL_B are a set of inverted signals.

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