Hall sensing chip and control method thereof

Abstract

The invention discloses a Hall sensing chip and a control method thereof. The Hall sensing chip comprises a Hall calibration module used for generating a first voltage and a second voltage according to a bias current, and a rotating current switch module connected with the Hall calibration module and used for alternately changing the direction of the bias current input into the Hall calibration module and enabling the Hall calibration module to alternately generate a first output voltage and a second output voltage. The analog-to-digital conversion module is connected with the rotating current switch module and is used for generating a first digital signal according to the first output voltage and generating a second digital signal according to the second output voltage; and the calibration module is respectively connected with the analog-to-digital conversion module and the rotating current switch module, and is used for generating bias current according to the first digital signal, the second digital signal and the reference signal. Closed-loop negative feedback self-calibration can effectively eliminate drift of sensitivity of the Hall sensing chip under temperature and stress changes.

Description

Technical Field

[0001] The present invention relates to the technical field of Hall sensor chips, and in particular to a Hall sensor chip and a control method thereof. Background Art

[0002] Magnetic signal sensors have a mature and complete industrial chain and a wide range of application scenarios. Among them, Hall sensors are widely used in automotive electronics and other fields due to their advantages such as low cost, small size, and high performance. However, Hall sensors themselves have many non-ideal factors, such as mismatch voltage and sensitivity drift. Among them, sensitivity drift will be affected by factors such as temperature and stress, and needs to be calibrated in a reasonable way. Summary of the invention

[0003] The present invention provides a Hall sensor chip and a control method thereof, so as to solve the sensitivity drift of the Hall sensor chip caused by factors such as environment and stress.

[0004] According to one aspect of the present invention, a Hall sensor chip is provided, comprising:

[0005] A calibrated Hall module, used to generate a first voltage according to a bias current and a first excitation current, and also used to generate a second voltage according to the bias current and the second excitation current, wherein the first excitation current and the second excitation current have different directions, and the first voltage and the second voltage are mutually anti-phase voltages;

[0006] a rotary current switch module, connected to the calibration Hall module, for alternately changing the direction of the bias current input into the calibration Hall module, and causing the calibration Hall module to alternately generate a first output voltage and a second output voltage; the first output voltage is equal to the sum of the first voltage and the mismatch voltage, and the second output voltage is equal to the sum of the second voltage and the mismatch voltage;

[0007] an analog-to-digital conversion module, connected to the rotary current switch module, and configured to generate a first digital signal according to the first output voltage, and further configured to generate a second digital signal according to the second output voltage;

[0008] A calibration module is connected to the analog-to-digital conversion module and the rotary current switch module respectively, and is used to generate the bias current according to the first digital signal, the second digital signal and a reference signal.

[0009] Optionally, the analog-to-digital conversion module includes:

[0010] an integrator, wherein an input end of the integrator is connected to the rotary current switch module, and is used to integrate the first output voltage to generate a first integrated signal; and is also used to integrate the second output voltage to generate a second integrated signal;

[0011] a comparator, wherein an input end of the comparator is connected to an output end of the integrator, and is used to generate a first pulse signal according to the first integrated signal, and is also used to generate a second pulse signal according to the second integrated signal;

[0012] A counter, wherein the input end of the counter is connected to the output end of the comparator, the output end of the counter is connected to the calibration module, and the counter is used to count the first pulse signal to generate the first digital signal, and is also used to count the second pulse signal to generate the second digital signal.

[0013] Optionally, the first pulse signal and the second pulse signal both include a first potential and a second potential, and the first potential and the second potential are high and low potentials to each other; and the analog-to-digital conversion module further includes:

[0014] a control switch, wherein the control end of the control switch is connected to the output end of the comparator, the output end of the control switch is connected to the input end of the integrator, the first potential output by the output end of the comparator is used to control the control switch to input a first reference voltage to the input end of the integrator, and the second potential output by the output end of the comparator is used to control the control switch to input a second reference voltage to the input end of the integrator; the first reference voltage and the second reference voltage are mutually inverted voltages;

[0015] The integrator is used to integrate the first output voltage and the voltage output from the output end of the control switch to generate a first integrated signal; and is also used to integrate the second output voltage and the voltage output from the output end of the control switch to generate a second integrated signal.

[0016] Optionally, the calibration module includes a calibration quantity generating unit, a digital-to-analog conversion unit and a bias current generating unit;

[0017] The input end of the calibration quantity generating unit is connected to the analog-to-digital conversion module, and the calibration quantity generating unit is used to generate a calibration digital quantity signal according to the difference between the first digital signal and the second digital signal and a reference signal;

[0018] The input end of the digital-to-analog conversion unit is connected to the output end of the calibration quantity generating unit, and the digital-to-analog conversion unit is used to generate a calibration current according to the calibration digital quantity signal;

[0019] The input end of the bias current generating unit is connected to the output end of the digital-to-analog conversion unit, the output end of the bias current generating unit is connected to the rotary current switch module, and the bias current generating unit is used to generate the bias current according to the calibration current.

[0020] Optionally, the Hall sensor chip also includes a main Hall module, which is connected to the calibration module, the main Hall module and the calibration module are connected to the same bias current, and the main Hall module and the calibration Hall module are under the same temperature and stress conditions.

[0021] According to another aspect of the present invention, a control method of a Hall sensor chip is also provided, which is applied to the above-mentioned Hall sensor chip;

[0022] The control method of the Hall sensor chip includes a plurality of continuous calibration stages, so that after the Hall sensor chip passes through the plurality of continuous calibration stages, the difference between the first digital signal and the second digital signal converges to the reference signal;

[0023] The calibration phase includes a conversion sub-phase and an adjustment sub-phase;

[0024] In the conversion sub-phase:

[0025] The calibration Hall module generates a first voltage according to a first excitation current and a bias current of an adjustment sub-stage of a previous calibration stage, and is also used to generate a second voltage according to the second excitation current and a bias current of an adjustment sub-stage of a previous calibration stage, wherein the first excitation current and the second excitation current have different directions, and the first voltage and the second voltage are mutually anti-phase voltages;

[0026] The rotary current switch module alternately changes the direction of the bias current input into the calibration Hall module, and enables the calibration Hall module to alternately generate a first output voltage and a second output voltage; the first output voltage is equal to the sum of the first voltage and the mismatch voltage, and the second output voltage is equal to the sum of the second voltage and the mismatch voltage;

[0027] The analog-to-digital conversion module generates a first digital signal according to the first output voltage, and is also used to generate a second digital signal according to the second output voltage;

[0028] In the regulation sub-phase:

[0029] The calibration module generates a bias current according to the first digital signal, the second digital signal and a reference signal.

[0030] Optionally, the conversion sub-stage includes a first conversion sub-stage and a second conversion sub-stage;

[0031] In the first conversion sub-stage:

[0032] The calibration Hall module generates the first voltage according to the first excitation current and the bias current of the adjustment sub-stage of the previous calibration stage;

[0033] The rotary current switch module alternately changes the direction of the bias current input into the calibration Hall module and generates the first output voltage;

[0034] The analog-to-digital conversion module generates the first digital signal according to the first output voltage;

[0035] In the second conversion sub-stage:

[0036] The calibration Hall module generates the second voltage according to the second excitation current and the bias current of the adjustment sub-stage of the previous calibration stage;

[0037] The rotary current switch module alternately changes the direction of the bias current input into the calibration Hall module and generates the second output voltage;

[0038] The analog-to-digital conversion module generates the second digital signal according to the second output voltage.

[0039] Optionally, the analog-to-digital conversion module includes: an integrator, the input end of the integrator is connected to the rotary current switch module; a comparator, the input end of the comparator is connected to the output end of the integrator; a counter, the input end of the counter is connected to the output end of the comparator, and the output end of the counter is connected to the calibration module;

[0040] In the first conversion sub-stage, the analog-to-digital conversion module generates a first digital signal according to the first output voltage, including:

[0041] The integrator integrates the first output voltage to generate a first integrated signal;

[0042] The comparator generates a first pulse signal according to the first integrated signal;

[0043] The counter counts the first pulse signal to generate the first digital signal;

[0044] In the second conversion sub-stage, the analog-to-digital conversion module generates the second digital signal according to the second output voltage, including:

[0045] The integrator integrates the second output voltage to generate a second integrated signal;

[0046] The comparator generates a second pulse signal according to the second integrated signal;

[0047] The counter counts the second pulse signal to generate the second digital signal.

[0048] Optionally, the calibration module includes a calibration quantity generating unit, a digital-to-analog conversion unit and a bias current generating unit; the input end of the calibration quantity generating unit is connected to the analog-to-digital conversion module, the digital-to-analog conversion unit is connected to the output end of the calibration quantity generating unit, the input end of the bias current generating unit is connected to the output end of the digital-to-analog conversion unit, and the output end of the bias current generating unit is connected to the rotary current switch module;

[0049] In the adjustment sub-stage, the calibration module generates a bias current according to the first digital signal, the second digital signal and the reference signal, including:

[0050] The calibration quantity generating unit generates a calibration digital quantity signal according to a difference between the first digital signal and the second digital signal and a reference signal;

[0051] The digital-to-analog conversion unit generates a calibration current according to the calibration digital quantity signal;

[0052] The bias current generating unit generates the bias current according to the calibration current.

[0053] Optionally, the Hall sensor chip further includes a main Hall module, and the main Hall module is connected to the calibration module. The control method of the Hall sensor chip further includes:

[0054] At the same time, the bias currents input into the main Hall module and the calibration Hall module are controlled to be the same; wherein the main Hall module and the calibration Hall module are under the same temperature and stress conditions.

[0055] In this embodiment, a first output voltage including a mismatch voltage and a second output voltage including a mismatch voltage are generated by calibrating the Hall module and the rotating current switch module, and then the first output voltage is converted into a first digital signal and the second output voltage is converted into a second digital signal by the analog-to-digital conversion module. The mismatch voltage is eliminated by performing a subtraction operation between the first digital signal and the second digital signal by the calibration module, ensuring that the subsequent calibration stage is not affected by the mismatch voltage and the accuracy of the calibration is guaranteed. On the basis of the analog front-end circuit of the traditional Hall sensor chip, a calibration channel is added. The closed-loop negative feedback self-calibration realized by the channel can effectively eliminate the drift of the sensitivity of the Hall sensor chip under temperature and stress changes, and obtain an analog output voltage with a programmable configuration temperature coefficient and size.

[0056] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0058] Figure 1 A schematic diagram of the structure of a Hall sensor chip provided by an embodiment of the present invention;

[0059] Figure 2 A schematic diagram of the structure of another Hall sensor chip provided by an embodiment of the present invention;

[0060] Figure 3 A timing diagram of a binary code stream outputted from an output terminal of a comparator in a Hall sensor chip provided by an embodiment of the present invention;

[0061] Figure 4 A timing diagram of an analog-to-digital conversion module in a Hall sensor chip provided by an embodiment of the present invention;

[0062] Figure 5 A timing diagram of a calibration module in a Hall sensor chip provided by an embodiment of the present invention;

[0063] Figure 6 A flow chart of a control method of a Hall sensor chip provided by an embodiment of the present invention;

[0064] Figure 7 A flow chart of another method for controlling a Hall sensor chip provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0065] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0066] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0067] Figure 1 A schematic diagram of the structure of a Hall sensor chip provided by an embodiment of the present invention, referring to Figure 1 , the Hall sensor chip includes:

[0068] A calibration Hall module 1 is used to generate a first voltage according to a bias current Ibias and a first excitation current, and is also used to generate a second voltage according to the bias current Ibias and the second excitation current, wherein the first excitation current and the second excitation current have different directions, and the first voltage Vin and the second voltage -Vin are mutually anti-phase voltages;

[0069] The rotary current switch module 2 is connected to the calibration Hall module 1 and is used to alternately change the direction of the bias current Ibias input into the calibration Hall module 1, and to enable the calibration Hall module 1 to alternately generate a first output voltage and a second output voltage; the first output voltage is equal to the sum of the first voltage Vin and the mismatch voltage Vosres, and the second output voltage is equal to the sum of the second voltage -Vin and the mismatch voltage Vosres;

[0070] The analog-to-digital conversion module 3 is connected to the rotary current switch module 2 and is used to generate a first digital signal D1 according to the first output voltage and to generate a second digital signal D2 according to the second output voltage;

[0071] The calibration module 4 is connected to the analog-to-digital conversion module 3 and the rotary current switch module 2 respectively, and is used to generate a bias current Ibias according to the first digital signal D1, the second digital signal D2 and the reference signal Dnom.

[0072] In an optional embodiment, the calibration Hall module 1 includes a modulation switch and two groups of Hall devices, namely a first group of Hall devices and a second group of Hall devices. The modulation switch is connected to the two groups of Hall devices respectively. Each group of Hall devices includes an excitation coil and a Hall disk. The excitation coil is arranged directly above the corresponding Hall disk, and the excitation coils in the two groups of Hall devices are connected in series, and the Hall disks in the two groups of Hall devices are connected in parallel. The second end of the excitation coil in the first group of Hall devices is connected to the first end of the excitation coil in the second group of Hall devices to form a series connection of the two excitation coils. And the first end of the excitation coil in the first group of Hall devices and the second end of the excitation coil in the second group of Hall devices are both connected to the modulation switch. The input end of the modulation switch receives a constant excitation current generated by an off-chip current source that does not change with temperature. After modulating it, the excitation current flows through the excitation coil to generate a periodic reference magnetic field B with constant magnitude and changing direction on the Hall disk below.

[0073] The modulation switch and the excitation coils in the two groups of Hall devices are used to generate a periodic reference magnetic field with constant size, changing direction and no temperature change. Specifically, at the same time, the directions of the reference magnetic field B generated by the two excitation coils under the action of the excitation current are opposite. For example, when the first excitation current is input to the two excitation coils in the calibration Hall module 1 under the action of the modulation switch, the current direction of the first excitation current on the excitation coils in the first group of Hall devices is clockwise, and the direction of the generated reference magnetic field B is inward, and the current direction of the first excitation current on the excitation coils in the second group of Hall devices is counterclockwise, and the direction of the generated reference magnetic field B is outward. When the direction of the excitation current input into the calibration Hall module is changed under the action of the modulation switch, and the second excitation current is input to the two excitation coils in the calibration Hall module 1, the current direction of the second excitation current on the excitation coils in the first group of Hall devices is counterclockwise, and the direction of the generated reference magnetic field B is outward, and the current direction of the second excitation current on the excitation coils in the second group of Hall devices is clockwise, and the direction of the generated reference magnetic field B is inward.

[0074] The working process of the Hall sensor chip includes multiple calibration stages, and the calibration stage includes a conversion sub-stage and an adjustment sub-stage. The calibration Hall module 1 is used to generate a first voltage Vin according to the first excitation current and the bias current Ibias generated by the calibration module 4 in the adjustment sub-stage of the previous calibration stage in the conversion sub-stage, and is also used to generate a second voltage -Vin according to the second excitation current and the bias current Ibias generated by the calibration module 4 in the adjustment sub-stage of the previous calibration stage in the conversion sub-stage. The conversion sub-stage also includes multiple control cycles, and the rotating current switch module 2 includes multiple sets of switches. The rotating current switch module 2 is used to control the conduction state of the multiple sets of switches in multiple control cycles of the conversion sub-stage, and alternately change the direction of the bias current Ibias in the input calibration Hall module 1 to reduce the mismatch voltage and low-frequency flicker noise of the calibration Hall module 1. The input end of the rotating current switch module 2 is used to receive the bias current Ibias, and after connecting the Hall disk, the first output voltage corresponding to the reference magnetic field B, which includes the first voltage and the analog quantity of the mismatch voltage, and the second output voltage including the second voltage and the analog quantity of the mismatch voltage are output to the analog-to-digital conversion module 3. Exemplarily, for any Hall disk, in the first control cycle, the rotating current switch module 2 controls the bias current Ibias input to the calibration Hall module 1 to be in the first direction, and in the second control cycle, the rotating current switch module 2 controls the bias current Ibias input to the calibration Hall module 1 to be in the second direction, and the first direction and the second direction are perpendicular. When the bias current Ibias is in the first direction, the Hall disk generates a first voltage between the first end and the second end of the Hall disk, wherein the connection direction of the first end and the second end is in the second direction, and when the bias current Ibias is in the second direction, the Hall disk generates a second voltage between the third end and the fourth end of the Hall disk, wherein the connection direction of the third end and the fourth end is in the first direction, and then controls the switch between the third end and the second end to be connected, and the switch between the fourth end and the first end to be connected, converting the voltage in the first direction to the voltage in the second direction, and the first voltage Vin and the second voltage -Vin are equal in magnitude, and are positive and negative voltages to each other, thereby reducing the magnitude of the mismatch voltage of the Hall disk. Finally, after eliminating part of the mismatch voltage by converting the direction of the bias current Ibias, part of the mismatch voltage still exists and is input into the subsequent analog-to-digital conversion module 3. Therefore, after the rotating current switch module 2, the first output voltage and the second output voltage containing the mismatch voltage are output to the analog-to-digital conversion module 3.

[0075] The analog-to-digital conversion module 3 is used to generate a first digital signal according to the first output voltage in the conversion sub-stage, and is also used to generate a second digital signal according to the second output voltage in the conversion sub-stage. The analog-to-digital conversion module 3 converts the first output voltage and the second output voltage of the analog quantity into digital quantity signals for output respectively. The calibration module 4 is used to generate a bias current Ibias according to the first digital signal D1, the second digital signal D2 and the reference signal Dnom in the adjustment sub-stage.

[0076] Since the first output voltage includes the mismatch voltage Vosres and the second output voltage includes the mismatch voltage Vosres, the first digital signal D1 corresponding to the first output voltage also includes the mismatch voltage Vosres, and the second digital signal D2 corresponding to the second output voltage also includes the mismatch voltage Vosres. The calibration module 4 obtains the deviation signal Df by taking the difference between the first digital signal D1 and the second digital signal D2. The deviation signal Df has nothing to do with the mismatch voltage Vosres, but is related to the first voltage Vin or the second voltage -Vin, thereby eliminating the influence of the mismatch voltage during calibration. Then the calibration module 4 is used to generate the bias current Ibias of the conversion sub-stage of the next calibration stage according to the difference between the deviation signal Df and the reference signal Dnom, and always maintain the bias current Ibias unchanged in the conversion sub-stage of the next calibration stage. Finally, after multiple consecutive calibration stages, the difference between the first digital signal D1 and the second digital signal D2 converges to the reference signal Dnom, and finally the first voltage Vin or the second voltage -Vin converges to a fixed value unchanged. Among them, the reference signal Dnom is a fixed digital code input outside the chip. Taking the first voltage Vin as a positive voltage and the second voltage -Vin as a negative voltage as an example, the first voltage Vin = S*Ibias*B, where B is the magnitude of the reference magnetic field generated by the excitation coil in the Hall calibration module 1. Under different temperature and stress conditions, the sensitivity S of the Hall disk will drift, so the generated first voltage Vin and the second voltage -Vin will change, so the first digital signal D1 and the second digital signal D2 generated by the analog-to-digital conversion module 3 will also change accordingly, causing the difference between the first digital signal D1 and the second digital signal D2 to change accordingly, and generate a difference with the input reference signal Dnom. Subsequently, the bias current Ibias of the Hall disk is continuously compensated by feedback through multiple calibration stages until the difference between the first digital signal D1 and the second digital signal D2 converges to the reference signal Dnom, so that the sensitivity S of the Hall disk and the product of the bias current Ibias can be kept relatively constant within a certain range. Optionally, the Hall sensor chip also includes a main Hall module, which is connected to the calibration module 4, and the main Hall module and the calibration Hall module 1 are connected to the same bias current Ibias, and the main Hall module and the calibration Hall module 1 are under the same temperature and stress conditions. Through reasonable layout, the main Hall module and the calibration Hall module 1 can be placed in the same temperature and stress environment, so that the two have the same sensitivity drift, and the bias current Ibias connected to the two is equal. Therefore, the output of the main Hall module realizes self-calibration of system sensitivity under different temperature stresses.

[0077] In this embodiment, a first output voltage including a mismatch voltage and a second output voltage including a mismatch voltage are generated by calibrating the Hall module and the rotating current switch module, and then the first output voltage is converted into a first digital signal and the second output voltage is converted into a second digital signal by the analog-to-digital conversion module. The mismatch signal is eliminated after the calibration module performs a subtraction operation on the first digital signal and the second digital signal, ensuring that the subsequent calibration stage is not affected by the mismatch voltage and the accuracy of the calibration is guaranteed. On the basis of the analog front-end circuit of the traditional Hall sensor chip, a calibration channel is added. The closed-loop negative feedback self-calibration realized by the channel can effectively eliminate the drift of the sensitivity of the Hall sensor chip under temperature and stress changes, and obtain an analog output voltage with a programmable configuration temperature coefficient and size.

[0078] Based on the above embodiments, Figure 2 A schematic diagram of the structure of another Hall sensor chip provided in an embodiment of the present invention, Figure 3 A timing diagram of a binary code stream outputted from an output terminal of a comparator in a Hall sensor chip provided by an embodiment of the present invention, wherein: Figure 3 A1 is the control signal of one group of switches in the modulation switch, A2 is the control signal of another group of switches, and di is the binary code stream outputted from the output end of the comparator 32. Figure 4 A timing diagram of an analog-to-digital conversion module in a Hall sensor chip provided by an embodiment of the present invention, referring to Figure 2-Figure 4 Optionally, the analog-to-digital conversion module 3 includes:

[0079] An integrator 31, the input end of which is connected to the rotary current switch module 2, and is used to integrate the first output voltage to generate a first integrated signal; and is also used to integrate the second output voltage to generate a second integrated signal;

[0080] A comparator 32, the input end of the comparator is connected to the output end Vint of the integrator 31, and is used to generate a first pulse signal according to the first integrated signal, and is also used to generate a second pulse signal according to the second integrated signal;

[0081] Counter 33, the input end of counter 33 is connected to the output end Vout of comparator 32, the output end Cout of counter 33 is connected to calibration module 4, counter 33 is used to count the first pulse signal to generate a first digital signal, and is also used to count the second pulse signal to generate a second digital signal.

[0082] In an optional embodiment, only the first output voltage and the second output voltage may be integrated. However, in order to eliminate noise and shape the signal in the input integrator 31 , in another optional embodiment, the analog-to-digital conversion module 3 may further include a control switch 33 . The first pulse signal and the second pulse signal both include a first potential and a second potential, and the first potential and the second potential are high and low potentials to each other; the analog-to-digital conversion module also includes: a control switch 33, the control end of the control switch is connected to the output end of the comparator, the output end of the control switch is connected to the input end of the integrator 31, the first potential output from the output end of the comparator controls the control switch 34 to input the first reference voltage Vref to the input end of the integrator 31, and the second potential output from the output end of the comparator controls the control switch 34 to input the second reference voltage -Vref to the input end of the integrator 31; the first reference voltage Vref and the second reference voltage -Vref are mutually inverted voltages, that is, the first reference voltage Vref and the second reference voltage -Vref are equal in magnitude, one is a positive voltage, and the other is a negative voltage; the integrator 31 is used to integrate the first output voltage and the voltage output from the output end of the control switch 33 to generate a first integrated signal; and is also used to integrate the second output voltage and the voltage output from the output end of the control switch 33 to generate a second integrated signal. Exemplarily, the first potential is a low potential 0, and the second potential is a high potential 1.

[0083] The conversion sub-stage includes a first conversion sub-stage and a second conversion sub-stage. In the first conversion sub-stage:

[0084] One of the switches inside the modulation switch is turned on, and the magnetic field induced by the excitation coil above the Hall disk causes the Hall disk to output a voltage signal of Vin. After entering the rotary current switch module 2 for modulation, the two phase signals are Vin+Vosres and -Vin+Vosres, and then the signal enters the integrator 31 in the incremental sigma delta ADC. The integrator 31 integrates the signal output by the rotary current switch module 2 and the ±Vref signal determined by the control switch 34 controlled by the feedback of the comparator 32 after superposition. The comparator 32 outputs the first potential or the second potential according to the positive or negative result of the integration, and continues to continuously feed back to the control switch 34 connected to the integrator 31. Exemplarily, when the comparator 32 outputs the first potential, the control switch 34 is controlled to output the first reference voltage Vref to the input end of the integrator 31, and when the comparator 32 outputs the second potential, the control switch 34 is controlled to output the second reference voltage -Vref to the input end of the integrator 31. Among them, the control switch 34 can be a multi-way selection switch, or other switches that can realize the time-sharing output of two voltages. Counter 33 acts as a simple digital filter to receive the binary code stream of comparator 32. nAfter a sampling period, the integration operation stops, the integrator 31 and the counter 33 are reset at the same time, and the calibration module 4 stores the first digital signal D1 output by the counter 33 at this time, that is, the digital code D1.

[0085]

[0086] Ideally, in the first conversion sub-stage t1, the rotating current is modulated, and the demodulation filtering at the output end of the integrator 31 can eliminate the mismatch voltage between the Hall disk and the integrator 31. However, in reality, the mismatch voltage cannot be completely eliminated through the chopping technology, so there is a residual offset, which seriously affects the accuracy of the digital code, so D1 contains the mismatch voltage.

[0087] In the second conversion sub-stage t2, after the first conversion sub-stage ends, the calibration module outputs a control signal to control another set of switches in the modulation switch 34 to be turned on, and the direction of the excitation current flowing through any excitation coil changes, thereby changing the direction of the reference magnetic field B generated, and the voltage signal output by the Hall disk becomes a second voltage -Vin. Similarly, after the rotating current modulation and the conversion by the analog-to-digital conversion module 3, a second digital signal D2 containing a mismatch voltage of the same magnitude, i.e., a digital code D2, is obtained.

[0088]

[0089] Figure 5 A timing diagram of a calibration module in a Hall sensor chip provided by an embodiment of the present invention, referring to Figure 2 and Figure 5 , Optionally, the calibration module 4 includes a calibration quantity generating unit 41, a digital-to-analog conversion unit 42 and a bias current generating unit 43;

[0090] The input end of the calibration quantity generating unit 41 is connected to the analog-to-digital conversion module 3, specifically connected to the output end Cout of the counter 33, and the calibration quantity generating unit 41 is used to generate a calibration digital quantity signal Dout according to the difference between the first digital signal D1 and the second digital signal D2 and the reference signal Dnom;

[0091] The input end of the digital-to-analog conversion unit 42 is connected to the output end of the calibration quantity generating unit 41, and the digital-to-analog conversion unit 42 is used to generate the calibration current Icom according to the calibration digital quantity signal;

[0092] The input end of the bias current generating unit 43 is connected to the output end of the digital-to-analog conversion unit 42 , and the output end of the bias current generating unit 43 is connected to the rotary current switch module 2 . The bias current generating unit 43 is used to generate a bias current Ibias according to the calibration current Icom.

[0093] The calibration value generating unit 41 stores the input digital code D2, and then subtracts D1 and D2 to eliminate the mismatch voltage in the digital code and calculate the digital code Df containing only the analog input signal information corresponding to the reference magnetic field.

[0094]

[0095] Subsequently, the calibration quantity generating unit 41 performs operation processing on the reference signal Dnom inputted from the chip, that is, the reference digital code Dnom, and the Df obtained by the above calculation to obtain a suitable digital compensation quantity, that is, the calibration digital quantity signal Dout. The digital-to-analog conversion unit 42 is a DAC converter, which is used to convert the digital quantity Dout into an analog current signal. The bias current generating unit 43 includes a voltage-current converter, which is used to generate a constant current Inom, and sum it with the calibration current Icom to obtain the final bias current Ibias.

[0096] When the Hall sensor chip is used to measure the magnetic field, its output voltage Vin is determined by the sensitivity S of the Hall disk, the bias current Ibias and the size B of the reference magnetic field in the vertical direction.

[0097] V in =S*Ibias*B;

[0098] Under different temperature and stress conditions, the sensitivity S of the Hall disk will drift, so the magnitude of the first output voltage or the second output voltage input to the analog-to-digital conversion module 3 will change, so the digital code Df obtained by the analog-to-digital conversion module 3 after the first conversion sub-stage and the second conversion sub-stage will also change accordingly, and produce a difference with the input reference signal Dnom. Subsequently, the bias current Ibias of the Hall disk is compensated by continuous feedback through multiple calibrations until the difference Df between the first digital signal and the second digital signal converges to the reference signal Dnom, so that the sensitivity S of the Hall disk and the product of the bias current Ibias can remain relatively constant within a certain range. In addition, since the Hall disk in the main Hall module of the main channel and the Hall disk in the calibration Hall module of the calibration channel can be placed in the same temperature and stress environment through reasonable layout, have the same sensitivity drift, and have equal bias currents, the output V o Under different temperature stresses, the system sensitivity is self-calibrated, where A is the signal chain gain of the main channel, B is ext At the same time, since the reference signal Dnom is input from outside the chip, it determines the temperature coefficient and sensitivity of the system, so this calibration method has a high degree of programmability and is convenient for subsequent adjustment.

[0099]

[0100] The present invention adds a calibration channel on the basis of the traditional Hall sensor chip analog front-end circuit. The closed-loop negative feedback self-calibration realized by the channel can effectively eliminate the drift of the sensitivity of the Hall sensor chip under temperature and stress changes, and obtain an analog output voltage with a programmable configuration temperature coefficient and size.

[0101] An embodiment of the present invention further provides a control method for a Hall sensor chip, which is applied to the Hall sensor chip in any of the above embodiments; Figure 6 A flow chart of a control method of a Hall sensor chip provided by an embodiment of the present invention, referring to Figure 1 and Figure 6 The control method of the Hall sensor chip includes a plurality of continuous calibration stages, so that after the Hall sensor chip passes through the plurality of continuous calibration stages, the difference between the first digital signal and the second digital signal converges to the reference signal;

[0102] The calibration phase includes a conversion sub-phase and an adjustment sub-phase.

[0103] S110: In the conversion sub-stage, the calibration Hall module 1 generates a first voltage according to the first excitation current and the bias current of the adjustment sub-stage of the previous calibration stage, and is also used to generate a second voltage according to the second excitation current and the bias current of the adjustment sub-stage of the previous calibration stage. The directions of the first excitation current and the second excitation current are different, and the first voltage and the second voltage are mutually anti-phase voltages.

[0104] At different moments in the conversion sub-phase, the current flowing into the excitation coil in the calibration Hall module 1 is changed, so that the direction of the reference magnetic field generated by the excitation coil changes, so that the calibration Hall module 1 generates a first voltage and a second voltage of equal magnitude, one positive and one negative.

[0105] S120: In the conversion sub-stage, the rotating current switch module 2 alternately changes the direction of the bias current of the input calibration Hall module 1, and makes the calibration Hall module 1 alternately generate a first output voltage and a second output voltage; the first output voltage is equal to the sum of the first voltage and the mismatch voltage, and the second output voltage is equal to the sum of the second voltage and the mismatch voltage.

[0106] Although the rotating current technology is added by the rotating current switch module 2 to eliminate the mismatch voltage, there is still a residual DC mismatch voltage, which causes the bias current generated subsequently to be inaccurate. The first output voltage including the mismatch voltage and the second output voltage including the mismatch voltage are generated by the rotating current switch module, so that the adaptation voltage needs to be eliminated through certain operations later.

[0107] S130: In the conversion sub-phase, the analog-to-digital conversion module 3 generates a first digital signal according to the first output voltage, and is also used to generate a second digital signal according to the second output voltage.

[0108] The analog signal of the residual DC offset is converted into a corresponding digital signal by the analog-to-digital conversion module 3, that is, a first digital signal and a second digital signal are obtained respectively.

[0109] S140: In the adjustment sub-phase, the calibration module generates a bias current according to the first digital signal, the second digital signal and the reference signal.

[0110] The calibration module obtains the digital code Df after performing a subtraction operation on the first digital signal and the second digital signal, thereby eliminating the mismatch signal, ensuring that the subsequent calibration stage is not affected by the mismatch voltage, and ensuring the accuracy of the calibration.

[0111] In this embodiment, a first output voltage including a mismatch voltage and a second output voltage including a mismatch voltage are generated by calibrating the Hall module and the rotating current switch module, and then the first output voltage is converted into a first digital signal and the second output voltage is converted into a second digital signal by the analog-to-digital conversion module. The mismatch signal is eliminated after the calibration module performs a subtraction operation on the first digital signal and the second digital signal, ensuring that the subsequent calibration stage is not affected by the mismatch voltage and the accuracy of the calibration is guaranteed.

[0112] The conversion sub-stage includes a first conversion sub-stage and a second conversion sub-stage. Furthermore, the above S110-S130 further include:

[0113] In the first conversion sub-stage:

[0114] The calibration Hall module 1 generates a first voltage according to the first excitation current and the bias current of the adjustment sub-stage of the previous calibration stage;

[0115] The rotary current switch module 2 alternately changes the direction of the bias current in the input calibration Hall module to reduce the mismatch voltage and generate a first output voltage;

[0116] The analog-to-digital conversion module 3 generates a first digital signal according to the first output voltage.

[0117] In the second conversion sub-phase:

[0118] The calibration Hall module 1 generates a second output voltage according to the second excitation current and the bias current of the adjustment sub-stage of the previous calibration stage;

[0119] The rotary current switch module 2 alternately changes the direction of the bias current in the input calibration Hall module to reduce the mismatch voltage and generate a second output voltage;

[0120] The analog-to-digital conversion module 3 generates a second digital signal according to the second output voltage.

[0121] In the first conversion sub-stage, the calibration Hall module 1 generates a first voltage, which is modulated by the rotating current switch module 2 to generate two phase signals, Vin+Vosres and -Vin+Vosres, and then enters the incremental ADC, i.e., the analog-to-digital conversion module 3, to generate a first digital signal. In the second conversion sub-stage, the direction of the excitation current in the excitation coil is changed so that the calibration Hall module 1 generates a second voltage, which is also modulated by the rotating current and converted by the high-precision ADC to obtain a second digital signal containing the same mismatch voltage as the first digital signal.

[0122] refer to Figure 2 Optionally, the analog-to-digital conversion module 3 includes: an integrator 31, the input end of the integrator 31 is connected to the rotary current switch module 2; a comparator 32, the input end of the comparator 32 is connected to the output end of the integrator 31; a counter 33, the input end of the counter 33 is connected to the output end of the comparator 32, and the output end of the counter 33 is connected to the calibration module 4.

[0123] In the first conversion sub-stage, the analog-to-digital conversion module 3 generates a first digital signal according to the first output voltage, including:

[0124] The integrator 31 integrates the first output voltage to generate a first integrated signal;

[0125] The comparator 32 generates a first pulse signal according to the first integrated signal;

[0126] The counter 33 counts the first pulse signal to generate a first digital signal.

[0127] In the second conversion sub-phase, the analog-to-digital conversion module 3 generates a second digital signal according to the second output voltage, including:

[0128] The integrator 31 integrates the second output voltage to generate a second integrated signal;

[0129] The comparator 32 generates a second pulse signal according to the second integrated signal;

[0130] The counter 33 counts the second pulse signal to generate a second digital signal.

[0131] The first pulse signal and the second pulse signal both include a first potential and a second potential, and the first potential and the second potential are high and low potentials to each other; the analog-to-digital conversion module 3 also includes: a control switch 34, the control end of the control switch 34 is connected to the output end of the comparator 32, and the output end of the control switch 34 is connected to the input end of the integrator 31. In the first conversion sub-stage, the first potential output of the comparator 32 controls the control switch 34 to input the first reference voltage to the input end of the integrator 31, and the second potential output of the comparator 32 controls the control switch 34 to input the second reference voltage to the input end of the integrator 31, and the first reference voltage and the second reference voltage are mutually inverted voltages. Further, in the first conversion sub-stage, the integrator 31 integrates the first output voltage, and generating a first integrated signal includes: the integrator 31 integrates the first output voltage and the voltage output from the output end of the control switch 34 to generate a first integrated signal. In the second conversion sub-stage, the integrator 31 integrates the second output voltage, and generating a second integrated signal includes: the integrator 31 also integrates the second output voltage and the voltage output from the output end of the control switch 34 to generate a second integrated signal.

[0132] Figure 7 A flowchart of another method for controlling a Hall sensor chip provided by an embodiment of the present invention, referring to Figure 2 and Figure 7 Optionally, the calibration module 4 includes a calibration quantity generating unit 41, a digital-to-analog conversion unit 42 and a bias current generating unit 43; the input end of the calibration quantity generating unit 41 is connected to the analog-to-digital conversion module 3, the input end of the digital-to-analog conversion unit 42 is connected to the output end of the calibration quantity generating unit 41, the input end of the bias current generating unit 43 is connected to the output end of the digital-to-analog conversion unit 42, and the output end of the bias current generating unit 43 is connected to the rotary current switch module 2. The Hall sensor chip also includes a main Hall module, which is connected to the calibration module, and at the same time, the bias current in the control input main Hall module and the calibration Hall module is the same; wherein the main Hall module and the calibration Hall module are under the same temperature and stress conditions.

[0133] The control method includes:

[0134] S111: In a first conversion sub-phase, the calibration Hall module 1 generates a first voltage according to a first excitation current and a bias current of an adjustment sub-phase of a previous calibration phase.

[0135] In the first conversion sub-phase, one group of switches inside the modulation switch in the calibration Hall module 1 is turned on, and the magnetic field induced by the excitation coil above the Hall disk causes the Hall disk to output a first voltage Vin.

[0136] S121: In the first conversion sub-phase, the rotary current switch module 2 alternately changes the direction of the bias current in the input calibration Hall module to reduce the mismatch voltage and generate a first output voltage.

[0137] After the first voltage Vin enters the rotating current modulation, the two phase signals are Vin+Vosres and -Vin+Vosres. Then the signal enters the integrator 31 in the incremental sigma delta ADC.

[0138] S131 : In the first conversion sub-phase, the integrator 31 integrates the first output voltage and the voltage output from the output end of the control switch 34 to generate a first integrated signal.

[0139] The integrator 31 integrates the signal output by the rotary current switch module 2 and the first reference voltage and the second reference voltage signal determined by the control switch 43 controlled by the comparator 32 through feedback.

[0140] S141: In the first conversion sub-stage, the comparator 32 generates a first pulse signal according to the first integrated signal; the first potential output of the comparator 32 controls the control switch 34 to input the first reference voltage to the input end of the integrator 31, and the second potential output of the comparator 32 controls the control switch 34 to input the second reference voltage to the input end of the integrator 31.

[0141] The comparator 32 outputs a first potential and a second potential according to the positive or negative value of the integration result, and continuously feeds back to the control switch 34 connected to the integrator 31 .

[0142] S151: The counter 33 counts the first pulse signal to generate a first digital signal.

[0143] The counter acts as a simple digital filter to receive the binary code stream from the comparator 32. n After a sampling period, the integration operation stops, the integrator 31 and the counter 33 are reset simultaneously, and the calibration amount generating unit 41 stores the first digital signal D1 output by the counter 33 .

[0144] S161: In the second conversion sub-phase, calibrating the Hall module 1 generates a second voltage according to the second excitation current and the bias current of the adjustment sub-phase of the previous calibration phase;

[0145] In the second conversion sub-stage, the calibration quantity generating unit 41 controls another set of switches in the modulation switch to open, the direction of the excitation current flowing through the excitation coil changes, the direction of the magnetic field generated thereby also changes, and the Hall disk outputs a second voltage -Vin.

[0146] S171: In the second conversion sub-phase, the rotary current switch module 2 alternately changes the direction of the bias current in the input calibration Hall module to reduce the mismatch voltage and generate a second output voltage.

[0147] The second voltage is modulated by the rotating current to obtain two phase signals Vin+Vosres and -Vin+Vosres, and then the signal enters the integrator 31 in the incremental sigma delta ADC.

[0148] S181 : In the second conversion sub-phase, the integrator 31 integrates the second output voltage and the voltage output from the output end of the control switch 34 to generate a second integrated signal.

[0149] The integrator 31 integrates the signal output by the rotary current switch module 2 and the first reference voltage and the second reference voltage signal determined by the control switch 43 controlled by the comparator 32 through feedback.

[0150] S191: In the second conversion sub-stage, the comparator 32 generates a second pulse signal according to the second integrated signal; the first potential output of the comparator 32 controls the control switch 34 to input the first reference voltage to the input end of the integrator 31, and the second potential output of the comparator 32 controls the control switch 34 to input the second reference voltage to the input end of the integrator 31.

[0151] The comparator 32 outputs a first potential and a second potential according to the positive or negative value of the integration result, and continuously feeds back to the control switch 34 connected to the integrator 31 .

[0152] S201: The counter 33 counts the second pulse signal to generate a second digital signal.

[0153] The counter acts as a simple digital filter to receive the binary code stream from the comparator 32. n After a sampling period, the integration operation stops, the integrator 31 and the counter 33 are reset simultaneously, and the calibration amount generating unit 41 stores the second digital signal D1 output by the counter 33 .

[0154] S211: The calibration quantity generating unit generates a calibration digital quantity signal according to the difference between the first digital signal and the second digital signal and a reference signal.

[0155] The calibration quantity generating unit subtracts the first digital signal from the second digital signal, eliminates the mismatch voltage in the digital code, and calculates a digital code Df containing only the first voltage or the second voltage corresponding to the reference magnetic field (the magnetic field generated by the excitation coil). Subsequently, the reference signal input from the chip is operated with the calculated Df to obtain a calibration digital quantity signal.

[0156] S221: The digital-to-analog conversion unit generates a calibration current according to the calibration digital signal.

[0157] S231: The bias current generating unit generates a bias current according to the calibration current.

[0158] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0159] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A Hall sensor chip, characterized in that: include: A calibrated Hall module, used to generate a first voltage according to a bias current and a first excitation current, and also used to generate a second voltage according to the bias current and the second excitation current, wherein the first excitation current and the second excitation current have different directions, and the first voltage and the second voltage are mutually anti-phase voltages; a rotary current switch module, connected to the calibration Hall module, for alternately changing the direction of the bias current input into the calibration Hall module, and causing the calibration Hall module to alternately generate a first output voltage and a second output voltage; the first output voltage is equal to the sum of the first voltage and the mismatch voltage, and the second output voltage is equal to the sum of the second voltage and the mismatch voltage; an analog-to-digital conversion module, connected to the rotary current switch module, and configured to generate a first digital signal according to the first output voltage, and further configured to generate a second digital signal according to the second output voltage; A calibration module is connected to the analog-to-digital conversion module and the rotary current switch module respectively, and is used to generate the bias current according to the first digital signal, the second digital signal and a reference signal.

2. The Hall sensor chip according to claim 1, characterized in that: The analog-to-digital conversion module comprises: an integrator, wherein an input end of the integrator is connected to the rotary current switch module, and is used to integrate the first output voltage to generate a first integrated signal; and is also used to integrate the second output voltage to generate a second integrated signal; a comparator, wherein an input end of the comparator is connected to an output end of the integrator, and is used to generate a first pulse signal according to the first integrated signal, and is also used to generate a second pulse signal according to the second integrated signal; A counter, wherein the input end of the counter is connected to the output end of the comparator, the output end of the counter is connected to the calibration module, and the counter is used to count the first pulse signal to generate the first digital signal, and is also used to count the second pulse signal to generate the second digital signal.

3. The Hall sensor chip according to claim 2, characterized in that: The first pulse signal and the second pulse signal both include a first potential and a second potential, and the first potential and the second potential are high and low potentials to each other; The analog-to-digital conversion module also includes: a control switch, wherein the control end of the control switch is connected to the output end of the comparator, the output end of the control switch is connected to the input end of the integrator, the first potential output by the output end of the comparator is used to control the control switch to input a first reference voltage to the input end of the integrator, and the second potential output by the output end of the comparator is used to control the control switch to input a second reference voltage to the input end of the integrator; the first reference voltage and the second reference voltage are mutually inverted voltages; The integrator is used to integrate the first output voltage and the voltage output from the output end of the control switch to generate a first integrated signal; and is also used to integrate the second output voltage and the voltage output from the output end of the control switch to generate a second integrated signal.

4. The Hall sensor chip according to claim 1, characterized in that: The calibration module includes a calibration quantity generating unit, a digital-to-analog conversion unit and a bias current generating unit; The input end of the calibration quantity generating unit is connected to the analog-to-digital conversion module, and the calibration quantity generating unit is used to generate a calibration digital quantity signal according to the difference between the first digital signal and the second digital signal and a reference signal; The input end of the digital-to-analog conversion unit is connected to the output end of the calibration quantity generating unit, and the digital-to-analog conversion unit is used to generate a calibration current according to the calibration digital quantity signal; The input end of the bias current generating unit is connected to the output end of the digital-to-analog conversion unit, the output end of the bias current generating unit is connected to the rotary current switch module, and the bias current generating unit is used to generate the bias current according to the calibration current.

5. The Hall sensor chip according to claim 1, characterized in that: It also includes a main Hall module, which is connected to the calibration module. The main Hall module and the calibration module are connected to the same bias current, and the main Hall module and the calibration Hall module are under the same temperature and stress conditions.

6. A control method for a Hall sensor chip, characterized in that: A Hall sensor chip applied to any one of claims 1 to 5; The control method of the Hall sensor chip includes a plurality of continuous calibration stages, so that after the Hall sensor chip passes through the plurality of continuous calibration stages, the difference between the first digital signal and the second digital signal converges to the reference signal; The calibration phase includes a conversion sub-phase and an adjustment sub-phase; In the conversion sub-phase: The calibration Hall module generates a first voltage according to a first excitation current and a bias current of an adjustment sub-stage of a previous calibration stage, and is also used to generate a second voltage according to the second excitation current and a bias current of an adjustment sub-stage of a previous calibration stage, wherein the first excitation current and the second excitation current have different directions, and the first voltage and the second voltage are mutually anti-phase voltages; The rotary current switch module alternately changes the direction of the bias current input into the calibration Hall module, and enables the calibration Hall module to alternately generate a first output voltage and a second output voltage; the first output voltage is equal to the sum of the first voltage and the mismatch voltage, and the second output voltage is equal to the sum of the second voltage and the mismatch voltage; The analog-to-digital conversion module generates a first digital signal according to the first output voltage, and is also used to generate a second digital signal according to the second output voltage; In the regulation sub-phase: The calibration module generates a bias current according to the first digital signal, the second digital signal and a reference signal.

7. The control method of the Hall sensor chip according to claim 6, characterized in that: The conversion sub-stage includes a first conversion sub-stage and a second conversion sub-stage; In the first conversion sub-stage: The calibration Hall module generates the first voltage according to the first excitation current and the bias current of the adjustment sub-stage of the previous calibration stage; The rotary current switch module alternately changes the direction of the bias current input into the calibration Hall module and generates the first output voltage; The analog-to-digital conversion module generates the first digital signal according to the first output voltage; In the second conversion sub-stage: The calibration Hall module generates the second voltage according to the second excitation current and the bias current of the adjustment sub-stage of the previous calibration stage; The rotary current switch module alternately changes the direction of the bias current input into the calibration Hall module and generates the second output voltage; The analog-to-digital conversion module generates the second digital signal according to the second output voltage.

8. The control method of the Hall sensor chip according to claim 7, characterized in that: The analog-to-digital conversion module includes: an integrator, an input end of the integrator is connected to the rotary current switch module; a comparator, an input end of the comparator is connected to an output end of the integrator; a counter, an input end of the counter is connected to an output end of the comparator, and an output end of the counter is connected to the calibration module; In the first conversion sub-stage, the analog-to-digital conversion module generates a first digital signal according to the first output voltage, including: The integrator integrates the first output voltage to generate a first integrated signal; The comparator generates a first pulse signal according to the first integrated signal; The counter counts the first pulse signal to generate the first digital signal; In the second conversion sub-stage, the analog-to-digital conversion module generates the second digital signal according to the second output voltage, including: The integrator integrates the second output voltage to generate a second integrated signal; The comparator generates a second pulse signal according to the second integrated signal; The counter counts the second pulse signal to generate the second digital signal.

9. The control method of the Hall sensor chip according to claim 6, characterized in that: The calibration module includes a calibration quantity generating unit, a digital-to-analog conversion unit and a bias current generating unit; the input end of the calibration quantity generating unit is connected to the analog-to-digital conversion module, the digital-to-analog conversion unit is connected to the output end of the calibration quantity generating unit, the input end of the bias current generating unit is connected to the output end of the digital-to-analog conversion unit, and the output end of the bias current generating unit is connected to the rotary current switch module; In the adjustment sub-stage, the calibration module generates a bias current according to the first digital signal, the second digital signal and the reference signal, including: The calibration quantity generating unit generates a calibration digital quantity signal according to a difference between the first digital signal and the second digital signal and a reference signal; The digital-to-analog conversion unit generates a calibration current according to the calibration digital quantity signal; The bias current generating unit generates the bias current according to the calibration current.

10. The control method of the Hall sensor chip according to claim 6, characterized in that: The Hall sensor chip further includes a main Hall module, and the main Hall module is connected to the calibration module. The control method of the Hall sensor chip further includes: At the same time, the bias currents input into the main Hall module and the calibration Hall module are controlled to be the same; wherein the main Hall module and the calibration Hall module are under the same temperature and stress conditions.

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