Hall sensing circuit and electronic equipment

Abstract

The invention discloses a Hall sensing circuit and electronic equipment, the Hall sensing circuit comprises a voltage stabilizing module, the first input end of the voltage stabilizing module is used for receiving excitation voltage, and the first output end and the second output end are equal. The input end of the Hall module is coupled to the second output end of the voltage stabilizing module, the grounding end of the Hall module is coupled to the reference ground, and the Hall voltage output end of the Hall module outputs Hall differential signals. The input end of the following current module is coupled to the first output end of the voltage stabilizing module. The input end of the threshold voltage module is coupled to the output end of the following current module, and the output end of the threshold voltage module outputs a threshold differential signal. The comparison module receives and compares the Hall differential signal and the threshold differential signal, and the output end outputs a comparison result. When the first output end and the second output end of the voltage stabilizing module are conducted, the input end of the following current module can obtain the current of the input end of the Hall module, so that the current change of the output end of the following current module is in positive correlation with the current change of the input end of the Hall module.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of Hall switch circuit, and particularly relates to a Hall sensing circuit and electronic equipment. BACKGROUND

[0002] The Hall sensor is a magnetic sensing element whose output (Hall voltage) is proportional to its excitation current. It is widely used in magnetic field detection sensors due to its small size, vibration resistance, impact resistance, high frequency, and the ability to be integrated into a silicon chip. It includes various magnetic comparators and magnetic switches.

[0003] In the traditional technology, the Hall sensor is excited by voltage, that is, a fixed voltage source is applied to the Hall sensor, and the current in the Hall sensor is V / R, where V is the voltage value of the voltage source, and R is the impedance of the Hall sensor. At room temperature, the impedance of the Hall sensor is relatively small, which ensures a large excitation current and a good signal-to-noise ratio. However, as the temperature rises, the impedance increases, the excitation current under the fixed voltage decreases, the output Hall voltage decreases, the sensitivity decreases, and even the switching function of the sensor may fail.

[0004] To improve the temperature adaptability, the prior art adds a temperature compensation circuit to improve the temperature adaptability of the Hall sensing circuit, but this increases the circuit overhead and test complexity, requires high and low temperature tests to determine the compensation coefficient, and increases the cost. In addition, packaging stress and long-term work may cause compensation deviation, making the threshold value of the Hall comparator unstable in the full temperature range. SUMMARY

[0005] The main purpose of the present application is to provide a Hall sensing circuit and electronic equipment, which aims to solve the problem of sensitivity reduction of the Hall sensor when the temperature changes, and does not need to add an additional temperature compensation circuit.

[0006] To achieve the above purpose, the Hall sensing circuit provided by the present application comprises: a voltage stabilizing module having a first input end, a first output end and a second output end, the first input end being used for receiving an excitation voltage, and the voltage values of the first output end and the second output end being equal; a Hall module having an input end, a ground end and a Hall voltage output end, the input end being coupled to the second output end of the voltage stabilizing module, the ground end being coupled to a reference ground, and the Hall voltage output end being used for outputting a Hall differential signal; a following current module having an input end and an output end, the input end being coupled to the first output end of the voltage stabilizing module; a threshold voltage module having an input end and an output end, the input end being coupled to the output end of the following current module, and the output end being used for outputting a threshold differential signal; a comparison module having an input end and an output end, the input end coupled to the Hall voltage output end of the Hall module and the output end of the threshold voltage module, the comparison module receiving and comparing the Hall differential signal and the threshold differential signal, the output end for outputting the comparison result of the Hall differential signal and the threshold differential signal; wherein, when the first output end and the second output end of the voltage stabilizing module are turned on, the currents of the first output end and the second output end are equal, so that the input end of the follow-up current module obtains the current of the input end of the Hall module, and the current variation of the output end of the follow-up current module is positively correlated with the current variation of the input end of the Hall module.

[0007] Optionally, the output end of the threshold voltage module includes a first threshold voltage output end and a second threshold voltage output end, the first threshold voltage output end for outputting a first threshold voltage, and the second threshold voltage output end for outputting a second threshold voltage, the voltage value of the first threshold voltage being higher than the voltage value of the second threshold voltage, the first threshold voltage and the second threshold voltage together constituting the threshold differential signal. The threshold voltage module selects the voltage range of the first threshold voltage and the voltage range of the second threshold voltage based on a threshold control signal.

[0008] Optionally, the voltage stabilizing module includes: a first operational amplifier having a non-inverting input end, an inverting input end and an output end, the inverting input end being the first input end of the voltage stabilizing module for accepting an excitation voltage; a first transistor having a first end, a second end and a control end, the first end being the first output end of the voltage stabilizing module coupled to a preset power supply, the second end being the second output end of the voltage stabilizing module coupled to the non-inverting input end of the first operational amplifier, and the control end coupled to the output end of the first operational amplifier.

[0009] Optionally, the follow-up current module includes: a second transistor having a first end, a second end and a control end, the first end being the input end of the follow-up current module coupled to the preset power supply, the second end being the output end of the follow-up current module, and the control end coupled to the output end of the first operational amplifier.

[0010] Optionally, the threshold voltage module includes: a first resistor, a second resistor, a third resistor and a fourth resistor coupled in sequence between the input end of the threshold voltage module and a reference ground, a first switch having a first end and a second end, the first end coupled to the input end of the threshold voltage module, and the second end coupled to the first threshold voltage output end. a second switch having a first end, a second end and a third end, the first end coupled between the first resistor and the second resistor, the second end coupled to the first threshold voltage output end, the third end coupled to the second threshold voltage output end; a third switch having a first end, a second end and a third end, the first end coupled between the second resistor and the third resistor, the second end coupled to the first threshold voltage output end, the third end coupled to the second threshold voltage output end; a fourth switch having a first end, a second end and a third end, the first end coupled between the third resistor and the fourth resistor, the second end coupled to the first threshold voltage output end, the third end coupled to the second threshold voltage output end; a fifth switch having a first end and a second end, the first end coupled to the reference ground, the second end coupled to the second threshold voltage output end; wherein the first switch and the fifth switch are configured to receive the threshold control signal and to close or open based on the threshold control signal, and the second switch, the third switch and the fourth switch are configured to receive the threshold control signal and to open or to close the respective second end or third end based on the threshold control signal to adjust the voltage range of the first threshold voltage and to adjust the voltage range of the second threshold voltage.

[0011] Optionally, the follow current module comprises: at least three third transistors in parallel, each of the third transistors having a first end, a second end and a control end, the first end of each of the third transistors coupled to the preset power supply as an input end of the follow current module, the control end of each of the third transistors coupled to the output end of the first operational amplifier; at least three sixth switches in parallel and corresponding to the at least three third transistors one by one, one end of each of the sixth switches coupled to the second end of the corresponding third transistor, and the other end being an output end of the follow current module.

[0012] Optionally, the threshold voltage module comprises: a sixth resistor having a first end and a second end, the first end being an input end of the threshold voltage module and a first threshold voltage output end; an adjustable resistor having a first end and a second end, the first end of the adjustable resistor coupled to the second end of the sixth resistor as a second threshold voltage output end, and the second end of the adjustable resistor coupled to a reference ground; The at least three sixth switches are configured to receive the threshold control signal, and are closed or turned off based on the threshold control signal, so as to adjust the voltage range of the first threshold voltage and adjust the voltage range of the second threshold voltage.

[0013] Optionally, the Hall module comprises: a Hall element having a first end, a second end, a third end and a fourth end, the first end being an input end of the Hall module, and the second end being a ground end of the Hall module; a differential amplifier having a first input end, a second input end, a first output end and a second output end, the first input end of the differential amplifier being coupled to the third end of the Hall element for receiving a first Hall voltage, the second input end of the differential amplifier being coupled to the fourth end of the Hall element for receiving a second Hall voltage, the first output end and the second output end of the differential amplifier being Hall voltage output ends of the Hall module, and being configured to output an amplified first Hall voltage and an amplified second Hall voltage respectively, the first Hall voltage being greater than the second Hall voltage, and the amplified first Hall voltage and the amplified second Hall voltage together constituting the Hall differential signal.

[0014] Optionally, the comparison module comprises: a four-input comparator having a first inverting input end, a second inverting input end, a first non-inverting input end and a second non-inverting input end, the first threshold voltage output end being coupled to the first inverting input end, the second threshold voltage output end being coupled to the first non-inverting input end, the first output end of the differential amplifier being coupled to the second inverting input end, and the second output end of the differential amplifier being coupled to the second non-inverting input end; or, a digital-to-analog converter having at least a first input end, a second input end, a third input end and a fourth input end, the first threshold voltage output end being coupled to the first input end, the second threshold voltage output end being coupled to the second input end, the first output end of the differential amplifier being coupled to the third input end, and the second output end of the differential amplifier being coupled to the fourth input end, the digital-to-analog converter being configured to compare the threshold differential signal and the Hall differential signal, and output a comparison result.

[0015] Optionally, the comparison module comprises: a sampling unit comprising a first capacitor, a second capacitor, a third capacitor and a fourth capacitor, a first end of the first capacitor is coupled to the first threshold voltage output terminal through a first sampling switch, a second end of the first capacitor is coupled to a reference ground, a first end of the second capacitor is coupled to the second threshold voltage output terminal through a second sampling switch, a second end of the second capacitor is coupled to the reference ground, a first end of the third capacitor is coupled to a first output terminal of the differential amplifier through a third sampling switch, a second end of the third capacitor is coupled to the reference ground, a first end of the fourth capacitor is coupled to a second output terminal of the differential amplifier through a fourth sampling switch, a second end of the fourth capacitor is coupled to the reference ground; a integrating unit comprising a first integrating capacitor and a second integrating capacitor, a first end of the first integrating capacitor is coupled to the first end of the first capacitor through a first integrating switch, the first end of the first integrating capacitor is also coupled to the first end of the third capacitor through a third integrating switch, a second end of the first integrating capacitor is coupled to the reference ground, a first end of the second integrating capacitor is coupled to the first end of the second capacitor through a second integrating switch, the first end of the second integrating capacitor is also coupled to the first end of the fourth capacitor through a fourth integrating switch, a second end of the second integrating capacitor is coupled to the reference ground; a two-input comparator having a third inverting input terminal and a third non-inverting input terminal, the third inverting input terminal is coupled to the first end of the first integrating capacitor, the third non-inverting input terminal is coupled to the first end of the second integrating capacitor; the first sampling switch, the second sampling switch, the third sampling switch and the fourth sampling switch are closed or turned off based on a first switch signal, the first integrating switch, the second integrating switch, the third integrating switch and the fourth integrating switch are closed or turned off based on a second switch signal, the first switch signal and the second switch signal are complementary pulse signals.

[0016] Optionally, the comparison module comprises: a sampling unit comprising a first capacitor, a second capacitor, a third capacitor and a fourth capacitor, a first end of the first capacitor is coupled to the first threshold voltage output terminal through a first sampling switch, a second end of the first capacitor is coupled to a reference ground, a first end of the second capacitor is coupled to the second threshold voltage output terminal through a second sampling switch, a second end of the second capacitor is coupled to the reference ground, a first end of the third capacitor is coupled to a first output terminal of the differential amplifier through a third sampling switch, a second end of the third capacitor is coupled to the reference ground, a first end of the fourth capacitor is coupled to a second output terminal of the differential amplifier through a fourth sampling switch, a second end of the fourth capacitor is coupled to the reference ground; The integrating unit comprises a first integrated capacitor and a second integrated capacitor, a first end of the first integrated capacitor is coupled to a first end of the first capacitor through a first integrated switch, the first end of the first integrated capacitor is also coupled to a first end of the third capacitor through a third integrated switch, and a second end of the first integrated capacitor is coupled to a reference ground; a first end of the second integrated capacitor is coupled to a first end of the second capacitor through a second integrated switch, the first end of the second integrated capacitor is also coupled to a first end of the fourth capacitor through a fourth integrated switch, and a second end of the second integrated capacitor is coupled to the reference ground; The digital-to-analog converter has at least a first input end and a second input end, the first input end is coupled to the first end of the first integrated capacitor, and the second input end is coupled to the first end of the second integrated capacitor; The first sampling switch, the second sampling switch, the third sampling switch and the fourth sampling switch are closed or turned off based on a first switch signal, and the first integrated switch, the second integrated switch, the third integrated switch and the fourth integrated switch are closed or turned off based on a second switch signal; the first switch signal and the second switch signal are complementary pulse signals.

[0017] The application further provides an electronic device comprising the Hall sensing circuit.

[0018] The following describes the application in detail. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from the structures shown in the drawings without creative labor.

[0020] Figure 1 FIG. 1 is a circuit framework diagram of a Hall sensing circuit according to the present application. Figure 2 A circuit diagram of the Hall sensor circuit provided by an embodiment of the present application; Figure 3 A circuit diagram of the Hall sensor circuit provided by another embodiment of the present application; Figure 4 A circuit of the comparison module provided by an embodiment of the present application Figure 1 ; Figure 5 A circuit of the comparison module provided by an embodiment of the present application Figure 2 ; Figure 6 A circuit of the comparison module provided by another embodiment of the present application Figure 3 .

[0021] Explanation of reference numerals: 10, voltage stabilizing module; 20, Hall module; 30, follow current module; 40, threshold voltage module; 50, comparison module.

[0022] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0024] In addition, the description such as “first”, “second” and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined with “first”, “second” can explicitly or implicitly include at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the fact that the technical solutions can be realized by those of ordinary skill in the art. When the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

[0025] Reference Figures 1 to 3 , Figure 1 A circuit framework diagram of the Hall sensor circuit of the present application; Figure 2 A circuit diagram of the Hall sensor circuit provided by an embodiment of the present application; Figure 3A circuit diagram of a Hall effect sensing circuit provided in another embodiment of the present invention.

[0026] like Figure 2 As shown in Embodiment 1 of this application, a Hall effect sensor circuit is disclosed, comprising a voltage regulator module 10, a Hall effect module 20, a current follower module 30, a threshold voltage module 40, and a comparison module 50. The voltage regulator module 10 has a first input terminal, a first output terminal, and a second output terminal. The first input terminal is used to receive an excitation voltage, and the first and second output terminals are equal. The Hall effect module 20 has an input terminal, a ground terminal, and a Hall voltage output terminal. The input terminal is coupled to the second output terminal of the voltage regulator module 10, the ground terminal is coupled to a reference ground, and the Hall voltage output terminal is used to output a Hall differential signal. The current follower module 30 has an input terminal and an output terminal, with the input terminal coupled to the first output terminal of the voltage regulator module 10. The threshold voltage module 40 has an input terminal and an output terminal, with the input terminal coupled to the output terminal of the current follower module 30, and the output terminal is used to output a threshold differential signal. The comparison module 50 has an input terminal and an output terminal. The input terminal is coupled to the Hall voltage output terminal of the Hall module 20 and the output terminal of the threshold voltage module 40. The comparison module 50 receives and compares the Hall differential signal and the threshold differential signal, and the output terminal is used to output the comparison result of the Hall differential signal and the threshold differential signal.

[0027] In Embodiment 1, when the first output terminal and the second output terminal of the voltage regulator module 10 are turned on, the currents of the first output terminal and the second output terminal are equal, so that the input terminal of the current follower module 30 obtains the current of the input terminal of the Hall module 20, and the current change of the output terminal of the current follower module 30 is positively correlated with the current change of the input terminal of the Hall module 20.

[0028] In traditional voltage-excitation schemes, the excitation current is I = V / R(T), where the excitation voltage V is fixed, while the sensor's internal impedance R(T) increases with temperature, leading to a significant decrease in the excitation current. Since the Hall voltage is proportional to the excitation current, a decrease in the excitation current directly reduces the amplitude of the output Hall voltage. In traditional voltage-excitation schemes, the threshold voltage of the Hall sensor fails to adjust synchronously with changes in the Hall voltage. This results in the Hall voltage potentially falling below the judgment threshold of the comparator circuit under high-temperature conditions, ultimately causing the comparator to fail to correctly identify changes in the magnetic field, affecting the reliability and stability of the sensor under high-temperature or wide-temperature conditions. Alternatively, some embodiments improve the temperature adaptability of the Hall sensor circuit by adding a temperature compensation circuit, but this increases circuit overhead and testing complexity, requiring high and low temperature tests to determine the compensation coefficient, thus increasing costs.

[0029] In this embodiment, a current-following module 30 is connected to the first output terminal of the voltage regulator module 10. When the first and second output terminals of the voltage regulator module 10 are turned on, since their output voltages are equal, the current-following module 30 can acquire current change information consistent with the excitation current of the Hall module 20. That is, the output current of the current-following module 30 and the excitation current of the Hall module 20 maintain a synchronous change relationship. The threshold voltage module 40 is driven by the output current of the current-following module 30, so the output terminal of the threshold voltage module 40 can output a threshold differential signal dynamically related to the excitation current of the Hall module 20. Compared with the above embodiment, which relies on a temperature compensation network and requires high and low temperature tests to calibrate the coefficient to improve the temperature adaptability of the Hall sensing circuit, this embodiment achieves temperature compensation through a current-following mechanism, avoiding external compensation components and calibration processes, and reducing system cost and testing complexity.

[0030] Specifically, the voltage regulator module 10 includes a first operational amplifier OP1, which has a non-inverting input, an inverting input, and an output. The inverting input is the first input of the voltage regulator module 10, used to receive the excitation voltage. The first transistor MOS1 has a first terminal, a second terminal, and a control terminal. The first terminal is the first output of the voltage regulator module 10, coupled to a preset power supply. The second terminal is the second output of the voltage regulator module 10, coupled to the non-inverting input of the first operational amplifier OP1. The control terminal is coupled to the output of the first operational amplifier OP1.

[0031] The output of the first operational amplifier OP1 drives the gate voltage of the first transistor MOS1 to adjust the conduction level of the first transistor MOS1, thereby implementing closed-loop control of the voltage at the second output of the voltage regulator module 10. When the voltage at the second output is lower than the excitation voltage, negative feedback causes the output voltage of the first operational amplifier OP1 to rise, enhancing the conduction of the first transistor MOS1; when the voltage at the second output is higher than the excitation voltage, the output voltage of the first operational amplifier OP1 drops, weakening the conduction of the first transistor MOS1. This continuous "detection-amplification-adjustment" cycle dynamically counteracts the disturbances caused by excitation voltage fluctuations and load changes to the second output, keeping the second output "locked" near the excitation voltage.

[0032] Furthermore, when the first transistor MOS1 is turned on, the input current from the preset power supply first enters the first transistor MOS1 through the first output terminal, and then flows out from the second output terminal to supply the Hall module 20. At this time, the current values ​​of the first output terminal and the second output terminal are equal and change equally.

[0033] The Hall module 20 includes a Hall element and a differential amplifier DA. The Hall element has a first end, a second end, a third end and a fourth end. The first end is an input end of the Hall module 20, and the second end is a ground end of the Hall module 20. The differential amplifier DA has a first input end, a second input end, a first output end and a second output end. The first input end of the differential amplifier DA is coupled to the third end of the Hall element to receive a first Hall voltage, and the second input end of the differential amplifier DA is coupled to the fourth end of the Hall element to receive a second Hall voltage. The first output end and the second output end of the differential amplifier DA are Hall voltage output ends of the Hall module 20, and are respectively used to output an amplified first Hall voltage and an amplified second Hall voltage. The first Hall voltage is greater than the second Hall voltage, and the amplified first Hall voltage and the amplified second Hall voltage together constitute a Hall differential signal.

[0034] The follower current module 30 includes a second transistor MOS2. The second transistor MOS2 has a first end, a second end and a control end. The first end is an input end of the follower current module 30 and is coupled to a preset power supply. The second end is an output end of the follower current module 30. The control end is coupled to an output end of the first operational amplifier OP1.

[0035] The second transistor MOS2 is coupled to the output end of the first operational amplifier OP1. When the first transistor MOS1 is turned on, the second transistor MOS2 is also turned on. The second transistor MOS2 is equivalent to a mirror branch of the first transistor MOS1. Both of them share the output voltage from the first operational amplifier OP1. The first end of the second transistor MOS2 is coupled to the first end of the first transistor MOS1 and is coupled to the same preset power supply. The current at the first end of the second transistor MOS2 can accurately copy the current at the first end of the first transistor MOS1. Thus, when the conduction current of the first transistor MOS1 changes, the second transistor MOS2 will respond synchronously to realize one-to-one correspondence and dynamic following between the output current and the Hall excitation current, and to provide the subsequent threshold voltage module 40 with a driving current that is real-time associated with the excitation current.

[0036] In the embodiment, the output end of the threshold voltage module 40 includes a first threshold voltage output end Y1 and a second threshold voltage output end Y2. The first threshold voltage output end Y1 is used to output a first threshold voltage, and the second threshold voltage output end Y2 is used to output a second threshold voltage. The voltage value of the first threshold voltage is higher than the voltage value of the second threshold voltage. The first threshold voltage and the second threshold voltage together constitute a threshold differential signal. The threshold voltage module 40 selects a voltage range of the first threshold voltage and a voltage range of the second threshold voltage based on a threshold control signal.

[0037] Specifically, the threshold voltage module 40 comprises a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4 coupled in sequence between an input terminal of the threshold voltage module 40 and a reference ground. The first switch S1 has a first end and a second end, the first end is coupled to the input terminal of the threshold voltage module 40, and the second end is coupled to a first threshold voltage output terminal Y1. The second switch S2 has a first end, a second end and a third end, the first end is coupled between the first resistor R1 and the second resistor R2, the second end is coupled to the first threshold voltage output terminal Y1, and the third end is coupled to a second threshold voltage output terminal Y2. The third switch S3 has a first end, a second end and a third end, the first end is coupled between the second resistor R2 and the third resistor R3, the second end is coupled to the first threshold voltage output terminal Y1, and the third end is coupled to the second threshold voltage output terminal Y2. The fourth switch S4 has a first end, a second end and a third end, the first end is coupled between the third resistor R3 and the fourth resistor R4, the second end is coupled to the first threshold voltage output terminal Y1, and the third end is coupled to the second threshold voltage output terminal Y2. The fifth switch S5 has a first end and a second end, the first end is coupled to the reference ground, and the second end is coupled to the second threshold voltage output terminal Y2. The first switch S1 and the fifth switch S5 are configured to receive a threshold control signal, and are configured to be closed or turned off based on the threshold control signal. The second switch S2, the third switch S3 and the fourth switch S4 are configured to receive the threshold control signal, and are configured to be turned off or to be closed by selecting the second end or the third end based on the threshold control signal, so as to adjust a voltage range of the first threshold voltage and to select a voltage range of the second threshold voltage.

[0038] In the embodiments of the present application, the threshold control signal is configured to adjust the voltage range of the first threshold voltage and to select the voltage range of the second threshold voltage by controlling any two of the five switches to be closed. In order to ensure that the voltage value of the first threshold voltage is higher than the voltage value of the second threshold voltage, among the two switches controlled to be closed, the switch close to the input terminal of the threshold voltage module 40 is connected to the first threshold voltage output terminal Y1, and the switch close to the output terminal of the threshold voltage module 40 is connected to the second threshold voltage output terminal Y2. Therefore, in the embodiments of the present application, the first switch S1 can only be connected to the first threshold voltage output terminal Y1 after being closed, and the fifth switch S5 can only be connected to the second threshold voltage output terminal Y2 after being closed. By selecting different switches to be closed, different impedances are introduced between the first threshold voltage output terminal Y1 and the second threshold voltage output terminal Y2, so as to adjust the voltage range of the first threshold voltage and to select the voltage range of the second threshold voltage.

[0039] Reference Figure 4In the embodiment of the present application, the comparison module 50 comprises a four-input comparator having a first inverting input terminal, a second inverting input terminal, a first non-inverting input terminal and a second non-inverting input terminal; the first threshold voltage output terminal Y1 is coupled to the first inverting input terminal, the second threshold voltage output terminal Y2 is coupled to the first non-inverting input terminal, the first output terminal of the differential amplifier DA is coupled to the second inverting input terminal, and the second output terminal of the differential amplifier DA is coupled to the second non-inverting input terminal.

[0040] The four-input comparator internally integrates two groups of differential comparators, and synthesizes the outputs of the two groups of differential comparators through a logic circuit, thereby being capable of simultaneously performing high-low threshold value judgment on the Hall differential signal and the threshold differential signal.

[0041] In some other embodiments, the comparison module 50 comprises a digital-to-analog converter having at least a first input terminal, a second input terminal, a third input terminal and a fourth input terminal; the first threshold voltage output terminal Y1 is coupled to the first input terminal, the second threshold voltage output terminal Y2 is coupled to the second input terminal, the first output terminal of the differential amplifier DA is coupled to the third input terminal, and the second output terminal of the differential amplifier DA is coupled to the fourth input terminal; the digital-to-analog converter is used for comparing the threshold differential signal and the Hall differential signal, and outputting a comparison result.

[0042] Reference Figure 5In some embodiments, the comparison module 50 includes a sampling unit, an integrating unit and a two-input comparator. The sampling unit includes a first capacitor C1, a second capacitor C2, a third capacitor C3 and a fourth capacitor C4, a first end of the first capacitor C1 is coupled to a first threshold voltage output end Y1 through a first sampling switch SW1, a second end is coupled to a reference ground, a first end of the second capacitor C2 is coupled to a second threshold voltage output end Y2 through a second sampling switch SW2, a second end is coupled to the reference ground, a first end of the third capacitor C3 is coupled to a first output end of a differential amplifier DA through a third sampling switch SW3, a second end is coupled to the reference ground, a first end of the fourth capacitor C4 is coupled to a second output end of the differential amplifier DA through a fourth sampling switch SW4, a second end is coupled to the reference ground; the integrating unit includes a first integrating capacitor C5 and a second integrating capacitor C6, a first end of the first integrating capacitor C5 is coupled to the first end of the first capacitor C1 through a first integrating switch SW5, the first end of the first integrating capacitor C5 is also coupled to the first end of the third capacitor C3 through a third integrating switch SW7, a second end of the first integrating capacitor is coupled to the reference ground; a first end of the second integrating capacitor C6 is coupled to the first end of the second capacitor C2 through a second integrating switch SW6, the first end of the second integrating capacitor C6 is also coupled to the first end of the fourth capacitor C4 through a fourth integrating switch SW8, a second end of the second integrating capacitor C6 is coupled to the reference ground; the two-input comparator has a third inverting input end and a third non-inverting input end, the third inverting input end is coupled to the first end of the first integrating capacitor, the third non-inverting input end is coupled to the first end of the second integrating capacitor.

[0043] The first sampling switch SW1, the second sampling switch SW2, the third sampling switch SW3 and the fourth sampling switch SW4 are closed or turned off based on a first switch signal, the first integrating switch SW5, the second integrating switch SW6, the third integrating switch SW7 and the fourth integrating switch SW8 are closed or turned off based on a second switch signal; the first switch signal and the second switch signal are complementary pulse signals.

[0044] In the sampling stage, the first switch signal controls the first sampling switch SW1, the second sampling switch SW2, the third sampling switch SW3 and the fourth sampling switch SW4 to be closed, and the second switch signal controls the first integration switch SW5, the second integration switch SW6, the third integration switch SW7 and the fourth integration switch SW8 to be turned off. At this time, the first capacitor C1 collects charges of the first threshold voltage output end Y1, the second capacitor C2 collects charges of the second threshold voltage output end Y2, the third capacitor C3 collects charges of the first output end of the differential amplifier DA, and the fourth capacitor C4 collects charges of the second output end of the differential amplifier DA. The charges of the corresponding signal voltage of the sampling end are stored between the two ends of each capacitor. In the integration stage, the first switch signal controls the first sampling switch SW1, the second sampling switch SW2, the third sampling switch SW3 and the fourth sampling switch SW4 to be turned off, and the second switch signal controls the first integration switch SW5, the second integration switch SW6, the third integration switch SW7 and the fourth integration switch SW8 to be closed. The first capacitor C1 and the third capacitor C3 are connected in parallel to the first integration capacitor C5, and the second capacitor C2 and the fourth capacitor C4 are connected in parallel to the second integration capacitor C6. Due to the conservation of charge, the voltage on the first integration capacitor C5 is proportional to the total charge on the original first capacitor C1 and the third capacitor C3, and the voltage on the second integration capacitor C6 is proportional to the total charge on the second capacitor C2 and the fourth capacitor C4. The two-input comparator sends the voltage of the first integration capacitor C5 to the inverting input end and sends the voltage of the second integration capacitor C6 to the non-inverting input end. When the voltage of the first integration capacitor C5 is greater than the voltage of the second integration capacitor C6, the output is high, indicating that the Hall differential signal exceeds the threshold differential signal; otherwise, the output is low.

[0045] Referring to Figure 6 In some other embodiments, the two-input comparator can also be replaced by a digital-to-analog converter, which has at least a first input end and a second input end. The first input end is coupled with the first end of the first integration capacitor, and the second input end is coupled with the first end of the second integration capacitor.

[0046] In this embodiment, by first sampling the threshold differential signal and the Hall differential signal respectively and accumulating charges on the same integration capacitor, the weighted sum of the two signals is equivalent to be realized, which can suppress the small voltage difference error better than the direct use of a single comparator, thereby improving the comparison accuracy.

[0047] As Figure 3As shown, the second embodiment of the present application discloses a Hall sensing circuit, and the difference between the second embodiment and the first embodiment lies in the follow-up current module 30 and the threshold voltage module 40. Specifically, the follow-up current module 30 in the second embodiment includes at least three third transistors MOS3 arranged in parallel, each of the third transistors MOS3 has a first end, a second end and a control end, the first end of each of the third transistors MOS3 is coupled to a preset power supply, serving as an input end of the follow-up current module 30, and the control end of each of the third transistors MOS3 is coupled to an output end of the first operational amplifier OP1; at least three sixth switches S6 arranged in parallel and corresponding to the at least three third transistors MOS3 one by one, one end of each of the sixth switches S6 is coupled to the second end of the corresponding third transistor MOS3, and the other end serves as an output end of the follow-up current module 30.

[0048] The threshold voltage module 40 includes a sixth resistor R6 and an adjustable resistor RV, the sixth resistor R6 has a first end and a second end, the first end serves as an input end and a first threshold voltage output end Y1 of the threshold voltage module 40; the adjustable resistor RV has a first end and a second end, the first end of the adjustable resistor RV is coupled to the second end of the sixth resistor R6, serving as a second threshold voltage output end Y2, and the second end of the adjustable resistor RV is coupled to a reference ground. Wherein, the at least three sixth switches S6 are used to receive a threshold control signal, and are closed or turned off based on the threshold control signal, so as to adjust the voltage range of the first threshold voltage and adjust the voltage range of the second threshold voltage.

[0049] In the second embodiment, the follow-up current module 30 expands the mirror function of the first transistor MOS1 to multiple parallel third transistor MOS3 branches, and the control end of each branch shares the output voltage of the first operational amplifier OP1. By closing different numbers of sixth switches S6, the corresponding third transistor MOS3 branch can be selectively connected. If two sixth switches S6 are closed in parallel, the current at the output end of the follow-up current module 30 is twice the single branch current, and if three sixth switches S6 are closed in parallel, the current at the output end of the follow-up current module 30 is three times the single branch current. In this way, the current received by the threshold voltage module 40 can jump between several preset gears, realizing current adjustment and changing the voltage range of the threshold voltage.

[0050] Further, the threshold voltage module 40 is composed of a fixed resistor R6 (pull-up) and an adjustable resistor RV (pull-down) to form a voltage dividing network. In actual operation, the adjustable resistor RV can also be adjusted to fine-tune the second threshold voltage in a continuous range, thereby realizing accurate control of the upper and lower limits of the comparison window.

[0051] The present application also discloses an electronic device comprising the Hall sensing circuit of any one of the above.

[0052] The above merely describes optional embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made under the inventive concept of the present application, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. A Hall effect sensing circuit, characterized in that, include: A voltage regulator module has a first input terminal, a first output terminal, and a second output terminal. The first input terminal is used to receive an excitation voltage, and the voltage values ​​of the first output terminal and the second output terminal are equal. The Hall module has an input terminal, a ground terminal, and a Hall voltage output terminal. The input terminal is coupled to the second output terminal of the voltage regulator module, the ground terminal is coupled to a reference ground, and the Hall voltage output terminal is used to output a Hall differential signal. The current-following module has an input terminal and an output terminal, wherein the input terminal is coupled to the first output terminal of the voltage regulator module; A threshold voltage module has an input terminal and an output terminal. The input terminal is coupled to the output terminal of the current follower module, and the output terminal is used to output a threshold differential signal. A comparison module has an input terminal and an output terminal. The input terminal is coupled to the Hall voltage output terminal of the Hall module and the output terminal of the threshold voltage module. The comparison module receives and compares the Hall differential signal and the threshold differential signal. The output terminal is used to output the comparison result of the Hall differential signal and the threshold differential signal. When the first and second output terminals of the voltage regulator module are turned on, the currents at the first and second output terminals are equal, so that the input terminal of the current follower module obtains the current at the input terminal of the Hall module, and the current change at the output terminal of the current follower module is positively correlated with the current change at the input terminal of the Hall module.

2. The Hall effect sensing circuit as described in claim 1, characterized in that, The output terminal of the threshold voltage module includes a first threshold voltage output terminal and a second threshold voltage output terminal. The first threshold voltage output terminal is used to output a first threshold voltage, and the second threshold voltage output terminal is used to output a second threshold voltage. The voltage value of the first threshold voltage is higher than the voltage value of the second threshold voltage. The first threshold voltage and the second threshold voltage together constitute the threshold differential signal. The threshold voltage module selects the voltage range of the first threshold voltage and the voltage range of the second threshold voltage based on the threshold control signal.

3. The Hall effect sensing circuit as described in claim 2, characterized in that, The voltage regulator module includes: The first operational amplifier has a non-inverting input terminal, an inverting input terminal, and an output terminal. The inverting input terminal is the first input terminal of the voltage regulator module and is used to receive the excitation voltage. The first transistor has a first terminal, a second terminal, and a control terminal. The first terminal is the first output terminal of the voltage regulator module and is coupled to a preset power supply. The second terminal is the second output terminal of the voltage regulator module and is coupled to the non-inverting input terminal of the first operational amplifier. The control terminal is coupled to the output terminal of the first operational amplifier.

4. The Hall effect sensing circuit as described in claim 3, characterized in that, The current-following module includes: The second transistor has a first terminal, a second terminal, and a control terminal. The first terminal is the input terminal of the current-following module and is coupled to the preset power supply. The second terminal is the output terminal of the current-following module, and the control terminal is coupled to the output terminal of the first operational amplifier.

5. The Hall effect sensing circuit as described in claim 4, characterized in that, The threshold voltage module includes: A first resistor, a second resistor, a third resistor, and a fourth resistor are sequentially coupled between the input terminal of the threshold voltage module and the reference ground. A first switch has a first terminal and a second terminal, the first terminal being coupled to the input terminal of the threshold voltage module, and the second terminal being coupled to the first threshold voltage output terminal. The second switch has a first terminal, a second terminal and a third terminal, the first terminal being coupled between the first resistor and the second resistor, the second terminal being coupled to the first threshold voltage output terminal, and the third terminal being coupled to the second threshold voltage output terminal. The third switch has a first terminal, a second terminal and a third terminal, the first terminal being coupled between the second resistor and the third resistor, the second terminal being coupled to the first threshold voltage output terminal, and the third terminal being coupled to the second threshold voltage output terminal; The fourth switch has a first terminal, a second terminal and a third terminal, the first terminal being coupled between the third resistor and the fourth resistor, the second terminal being coupled to the first threshold voltage output terminal, and the third terminal being coupled to the second threshold voltage output terminal; The fifth switch has a first terminal and a second terminal, the first terminal being coupled to the reference ground and the second terminal being coupled to the second threshold voltage output terminal; Wherein, the first switch and the fifth switch are used to receive the threshold control signal and close or close based on the threshold control signal; the second switch, the third switch, and the fourth switch are used to receive the threshold control signal and close or select their respective second or third terminals to close based on the threshold control signal, so as to adjust the voltage range of the first threshold voltage and the voltage range of the second threshold voltage.

6. The Hall effect sensing circuit as described in claim 3, characterized in that, The current-following module includes: At least three third transistors are arranged in parallel. Each third transistor has a first terminal, a second terminal, and a control terminal. The first terminal of each third transistor is coupled to the preset power supply and serves as the input terminal of the current-following module. The control terminal of each third transistor is coupled to the output terminal of the first operational amplifier. At least three sixth switches are arranged in parallel and correspond one-to-one with the at least three third transistors. One end of each sixth switch is coupled to the second end of the corresponding third transistor, and the other end is the output terminal of the current-following module.

7. The Hall effect sensing circuit as described in claim 6, characterized in that, The threshold voltage module includes: The sixth resistor has a first terminal and a second terminal, wherein the first terminal is the input terminal and the first threshold voltage output terminal of the threshold voltage module; An adjustable resistor has a first terminal and a second terminal, wherein the first terminal of the adjustable resistor is coupled to the second terminal of the sixth resistor and serves as the second threshold voltage output terminal, and the second terminal of the adjustable resistor is coupled to a reference ground; The at least three sixth switches are used to receive the threshold control signal and, based on the threshold control signal, to close or close to adjust the voltage range of the first threshold voltage and the voltage range of the second threshold voltage.

8. The Hall effect sensing circuit as described in claim 2, characterized in that, The Hall module includes: The Hall element has a first terminal, a second terminal, a third terminal, and a fourth terminal. The first terminal is the input terminal of the Hall module, and the second terminal is the ground terminal of the Hall module. A differential amplifier has a first input terminal, a second input terminal, a first output terminal, and a second output terminal. The first input terminal of the differential amplifier is coupled to the third terminal of the Hall element to receive a first Hall voltage. The second input terminal of the differential amplifier is coupled to the fourth terminal of the Hall element to receive a second Hall voltage. The first and second output terminals of the differential amplifier are the Hall voltage output terminals of the Hall module, respectively used to output the amplified first Hall voltage and the amplified second Hall voltage. The first Hall voltage is greater than the second Hall voltage. The amplified first Hall voltage and the amplified second Hall voltage together constitute the Hall differential signal.

9. The Hall effect sensing circuit as described in claim 8, characterized in that, The comparison module includes: A four-input comparator has a first inverting input, a second inverting input, a first non-inverting input, and a second non-inverting input; a first threshold voltage output is coupled to the first inverting input, a second threshold voltage output is coupled to the first non-inverting input, a first output of a differential amplifier is coupled to the second inverting input, and a second output of the differential amplifier is coupled to the second non-inverting input; or, A digital-to-analog converter (DAC) has at least a first input terminal, a second input terminal, a third input terminal, and a fourth input terminal. A first threshold voltage output terminal is coupled to the first input terminal, a second threshold voltage output terminal is coupled to the second input terminal, a first output terminal of the differential amplifier is coupled to the third input terminal, and a second output terminal of the differential amplifier is coupled to the fourth input terminal. The DAC is used to compare the threshold differential signal and the Hall differential signal and output the comparison result.

10. The Hall effect sensing circuit as described in claim 8, characterized in that, The comparison module includes: The sampling unit includes a first capacitor, a second capacitor, a third capacitor, and a fourth capacitor. The first terminal of the first capacitor is coupled to the first threshold voltage output terminal through a first sampling switch, and the second terminal is coupled to a reference ground. The first terminal of the second capacitor is coupled to the second threshold voltage output terminal through a second sampling switch, and the second terminal is coupled to a reference ground. The first terminal of the third capacitor is coupled to the first output terminal of the differential amplifier through a third sampling switch, and the second terminal is coupled to a reference ground. The first terminal of the fourth capacitor is coupled to the second output terminal of the differential amplifier through a fourth sampling switch, and the second terminal is coupled to a reference ground. The integrated unit includes a first integrated capacitor and a second integrated capacitor. A first terminal of the first integrated capacitor is coupled to a first terminal of the first capacitor via a first integrated switch. The first terminal of the first integrated capacitor is also coupled to a first terminal of the third capacitor via a third integrated switch. The second terminal of the first integrated capacitor is coupled to a reference ground. A first terminal of the second integrated capacitor is coupled to a first terminal of the second capacitor via a second integrated switch. The first terminal of the second integrated capacitor is also coupled to a first terminal of the fourth capacitor via a fourth integrated switch. The second terminal of the second integrated capacitor is coupled to a reference ground. A two-input comparator has a third inverting input terminal and a third non-inverting input terminal. The third inverting input terminal is coupled to a first terminal of the first integrated capacitor, and the third non-inverting input terminal is coupled to a first terminal of the second integrated capacitor. The first sampling switch, the second sampling switch, the third sampling switch, and the fourth sampling switch are closed or closed based on the first switching signal, and the first integrated switch, the second integrated switch, the third integrated switch, and the fourth integrated switch are closed or closed based on the second switching signal; the first switching signal and the second switching signal are complementary pulse signals.

11. The Hall effect sensing circuit as described in claim 8, characterized in that, The comparison module includes: The sampling unit includes a first capacitor, a second capacitor, a third capacitor, and a fourth capacitor. The first terminal of the first capacitor is coupled to the first threshold voltage output terminal through a first sampling switch, and the second terminal is coupled to a reference ground. The first terminal of the second capacitor is coupled to the second threshold voltage output terminal through a second sampling switch, and the second terminal is coupled to a reference ground. The first terminal of the third capacitor is coupled to the first output terminal of the differential amplifier through a third sampling switch, and the second terminal is coupled to a reference ground. The first terminal of the fourth capacitor is coupled to the second output terminal of the differential amplifier through a fourth sampling switch, and the second terminal is coupled to a reference ground. The integrated unit includes a first integrated capacitor and a second integrated capacitor. A first terminal of the first integrated capacitor is coupled to a first terminal of the first capacitor via a first integrated switch. The first terminal of the first integrated capacitor is also coupled to a first terminal of the third capacitor via a third integrated switch. The second terminal of the first integrated capacitor is coupled to a reference ground. A first terminal of the second integrated capacitor is coupled to a first terminal of the second capacitor via a second integrated switch. The first terminal of the second integrated capacitor is also coupled to a first terminal of the fourth capacitor via a fourth integrated switch. The second terminal of the second integrated capacitor is coupled to a reference ground. A digital-to-analog converter has at least a first input terminal and a second input terminal, wherein the first input terminal is coupled to a first terminal of a first integrated capacitor, and the second input terminal is coupled to a first terminal of a second integrated capacitor; The first sampling switch, the second sampling switch, the third sampling switch, and the fourth sampling switch are closed or closed based on the first switching signal, and the first integrated switch, the second integrated switch, the third integrated switch, and the fourth integrated switch are closed or closed based on the second switching signal; the first switching signal and the second switching signal are complementary pulse signals.

12. An electronic device, characterized in that, Includes the Hall sensor circuit as described in any one of claims 1-11.

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