A circuit structure for correcting distortion of a hall sensor output signal

Abstract

A kind of circuit structure for correcting the distortion of Hall sensor output signal, including four-phase rotating current circuit, first Hall sensor, power supply voltage and bias circuit, input end Vcm inputs the common-mode voltage control signal of ideal state first Hall sensor not affected by MOS tube resistance to operational amplifier reverse input, negative feedback regulating circuit comprising second Hall sensor, operational amplifier and MOS tube 1~2, so that the control signal input by input end Vcm is transmitted to the gate of MOS tube M1~2, the voltage of each node of the MOS tube in the first Hall sensor and four-phase rotating current circuit is adjusted by controlling the gate voltage of MOS tube M1~2, so that output common-mode voltage signal returns to stable value, thereby correcting the distortion of Hall sensor output signal.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of Hall sensor, in particular to a circuit structure for correcting the distortion of Hall sensor output signal. BACKGROUND

[0002] The Hall sensor manufactured based on CMOS process can integrate the Hall sensor and signal processing circuit on a chip, and generally adopts a rotating current circuit to modulate the signal of the Hall sensor. The rotating current circuit generally adopts a plurality of MOS tubes as circuit switches, and each MOS tube gate controls the MOS tube to be turned on or turned off according to a clock signal. When the clock signal received by the MOS tube gate is flipped, the MOS tube connected with the Hall sensor is switched, the direction of the bias current flowing through the Hall sensor is changed, and the gate-source voltage (V GS ) of the MOS tube is also changed to change the on-resistance. Although the bias circuit provides a bias current to the rotating current circuit in the prior art, so that the current flowing through the MOS tube is unchanged, the change of the resistance causes the common-mode voltage to change, thereby affecting the voltage of each node of the rotating current circuit. Thus, the common-mode voltage signal actually output by the Hall sensor is different from the common-mode voltage of the original output signal of the Hall sensor, which causes the distortion of the output signal of the Hall sensor. SUMMARY

[0003] To solve the defect of the prior art that causes the distortion of the output signal of the Hall sensor, the present application provides a circuit structure for correcting the distortion of the output signal of the Hall sensor.

[0004] The technical solution of the present application is: a circuit structure for correcting the distortion of the output signal of the Hall sensor, which comprises a four-phase rotating current circuit, a first Hall sensor arranged in the four-phase rotating current circuit, a power supply voltage for providing current for the four-phase rotating current circuit and the first Hall sensor, and a bias circuit for providing a bias current for the four-phase rotating current circuit and the first Hall sensor.

[0005] The power supply voltage is further connected with a common-mode voltage correction circuit for correcting the common-mode voltage of the first Hall sensor, the common-mode voltage correction circuit comprises an input end Vcm, an operational amplifier, MOS tubes M1-M6 and a second Hall sensor, the power supply voltage provides current for the four-phase rotating current circuit through the MOS tube M1, the power supply voltage provides current for the second Hall sensor through the MOS tubes M2-M3, the gate of the MOS tube M3 is grounded, the second Hall sensor is connected with the bias circuit through the MOS tube M4, and the MOS tubes M5-M6 are respectively connected with the W pole and the E pole of the second Hall sensor.

[0006] The input end Vcm inputs a control voltage signal which is a common-mode voltage output by the four-phase rotating current circuit to the inverting input end of the operational amplifier, the second Hall sensor is connected to the non-inverting input end of the operational amplifier through MOS tubes M5-M6, the output end of the operational amplifier is connected to the non-inverting input end of the operational amplifier through a capacitor, and the output end of the operational amplifier is connected to the gate of MOS tubes M1-M2 respectively, and the drain of MOS tube M1 and the drain of MOS tube M2 are connected.

[0007] Preferably, the four-phase rotating current circuit comprises MOS tubes MN1-MN12, MOS tubes MP1-4, an output end Vout1 and an output end Vout2, the N pole of the first Hall sensor is connected to the drain of MOS tube MN1, the source of MOS tube MN2, the drain of MOS tube MP1 and the drain of MOS tube MN3 respectively, the W pole of the first Hall sensor is connected to the drain of MOS tube MN4, the source of MOS tube MN5, the drain of MOS tube MP2 and the drain of MOS tube MN6 respectively, the S pole of the first Hall sensor is connected to the drain of MOS tube MP3, the drain of MOS tube MN7, the drain of MOS tube MN8 and the source of MOS tube MN9 respectively, the E pole of the first Hall sensor is connected to the drain of MOS tube MP4, the drain of MOS tube MN10, the drain of MOS tube MN11 and the source of MOS tube MN12 respectively, the drain of MOS tube MN2, the drain of MOS tube MN5, the drain of MOS tube MN9 and the drain of MOS tube MN12 output a common-mode voltage signal through the output end Vout1, the source of MOS tube MN3, the source of MOS tube MN4, the source of MOS tube MN7 and the source of MOS tube MN11 output a common-mode voltage signal through the output end Vout2, and the gates of MOS tubes MN1-MN12 and MOS tubes MP1-4 receive clock signals respectively.

[0008] Preferably, the bias circuit comprises a bias current source I0, a Hall sensor bias current source Ibias and MOS tubes M7-M13, the bias current source I0 is connected to the drain of MOS tube M7, the gate of MOS tube M7, the gate of MOS tube M8, the gate of MOS tube M10 and the gate of MOS tube M12 in sequence, the Hall sensor bias current source Ibias is connected to the drain of MOS tube M8, the gate of MOS tube M9, the gate of MOS tube M11 and the gate of MOS tube M13 in sequence, the source of MOS tube M8 is connected to the drain of MOS tube M9, the source of MOS tube M10 is connected to the drain of MOS tube M11, the source of MOS tube M12 is connected to the drain of MOS tube M13, the source of MOS tube M7, the source of MOS tube M9, the source of MOS tube M11 and the source of MOS tube M13 are all grounded, and the drain of MOS tube M10 is connected to the source of MOS tube M5.

[0009] Preferably, the MOS tubes M1-M3 are P-type MOS tubes, the MOS tubes M4-M13 are N-type MOS tubes, the power voltage provides current for the four-phase rotating current circuit and the first Hall sensor through the MOS tube M1, the drain of the MOS tubes M1-M2 are connected with the MOS tubes MP1-4, the power voltage provides current for the second Hall sensor through the MOS tubes M2-M3 in turn, the N pole of the second Hall sensor is connected with the drain of the MOS tube M3, and the S pole of the second Hall sensor is connected with the MOS tube M4.

[0010] The source of the MOS tube M12 is connected with the drain of the MOS tube MN1, the MOS tube MN6, the MOS tube MN8 and the MOS tube MN10 respectively, the bias current source I0 is grounded through the MOS tube M7, the Hall sensor bias current source Ibias is grounded through the MOS tubes M8-M9 in turn, the four-phase rotating current circuit is grounded through the MOS tubes M12-M13 in turn, and the second Hall sensor is grounded through the MOS tubes M10-M11 in turn.

[0011] Preferably, the MOS tubes M1, M2 and M5 are N-type MOS tubes, the MOS tubes M3, M4 and M6-M13 are P-type MOS tubes, the four-phase rotating current circuit is grounded through the MOS tube M1, the MOS tube M1 is connected with the MOS tube MN1, the MOS tube MN6, the MOS tube MN8 and the MOS tube MN10 respectively, the second Hall sensor is grounded through the MOS tubes 2-3, the S pole of the second Hall sensor is connected with the drain of the MOS tube M3, and the N pole of the second Hall sensor is connected with the drain of the MOS tube M4.

[0012] The MOS tube M13 is connected with the MOS tubes MP1-4 respectively, the power voltage provides current for the four-phase rotating current circuit and the first Hall sensor through the MOS tubes M12-M13 in turn, the power voltage provides current for the second Hall sensor through the MOS tubes M10-M11 and the MOS tube M4 in turn, the power voltage is connected with the bias current source Ibias through the MOS tubes M8-M9 in turn, the current outflow end of the bias current source Ibias is grounded, the power voltage is connected with the bias current source I0 through the MOS tube M7, and the current outflow end of the bias current source I0 is grounded.

[0013] Preferably, the P-type MOS tubes are all of the same size, and the N-type MOS tubes are all of the same size.

[0014] The beneficial effects of the present application: the input end Vcm inputs a common-mode voltage control signal which is not affected by the MOS tube resistance in the ideal state to the inverting input end of the operational amplifier, the negative feedback regulation circuit composed of the second Hall sensor, the operational amplifier and the MOS tubes 1-2 makes the control signal input by the input end Vcm transmitted to the gate of the MOS tube M1-2, the voltage of the gate of the MOS tube M1-2 is controlled to realize the regulation of the node voltage of the MOS tube in the first Hall sensor and the four-phase rotating current circuit, the output common-mode voltage signal returns to a stable value, thereby correcting the distortion of the Hall sensor output signal. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a circuit structure schematic diagram of the present application;

[0016] Figure 2 It is a circuit structure schematic diagram of the first embodiment;

[0017] Figure 3 It is a circuit structure schematic diagram of the second embodiment. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and advantages of the present application more clear, the following will be described in detail in combination with the drawings and specific embodiments.

[0019] The technical solution of the present application is as follows: a circuit structure for correcting the distortion of the Hall sensor output signal, comprising a four-phase rotating current circuit, a first Hall sensor arranged in the four-phase rotating current circuit, a power supply voltage for providing current for the four-phase rotating current circuit and the first Hall sensor, and a bias circuit for providing a bias current for the four-phase rotating current circuit and the first Hall sensor;

[0020] The power supply voltage is also connected with a common-mode voltage correction circuit for correcting the common-mode voltage of the first Hall sensor, as shown in Figure 1 The common-mode voltage correction circuit comprises an input end Vcm, an operational amplifier, MOS tubes MP1-M6 and a second Hall sensor, Figure 1 VDD in the common-mode voltage correction circuit is the power supply voltage, the power supply voltage provides current for the four-phase rotating current circuit through the MOS tube M1, the power supply voltage provides current for the second Hall sensor through the MOS tubes M2-3, the second Hall sensor is grounded at the gate of the MOS tube M3, the second Hall sensor is connected with the bias circuit through the MOS tube M4, and the MOS tubes M5-6 are respectively connected with the W pole and the E pole of the second Hall sensor;

[0021] The input end Vcm inputs a control voltage signal which is a common-mode voltage output by the four-phase rotating current circuit to the inverting input end of the operational amplifier, the second Hall sensor is connected to the non-inverting input end of the operational amplifier through MOS tubes M5-M6, the output end of the operational amplifier is connected to the non-inverting input end of the operational amplifier through a capacitor, and the output end of the operational amplifier is connected to the gate of MOS tubes M1-M2 respectively, and the drain of MOS tube M1 is connected to the drain of MOS tube M2.

[0022] Circuit principle: the input end Vcm inputs a control voltage signal which is a common-mode voltage of the first Hall sensor not affected by the resistance of the MOS tube in an ideal state to the inverting input end of the operational amplifier, and the control voltage signal is an average value of the common-mode voltage of the first Hall sensor at two output ends of the four-phase rotating current circuit. Since the first Hall sensor and the second Hall sensor are connected in parallel in the circuit branch, and the types, quantities, sizes and connection modes of the electrical elements on the two circuits are the same, the common-mode voltage signal of the second Hall sensor follows the common-mode voltage change of the first Hall sensor, the second Hall sensor sends the changed common-mode voltage signal to the non-inverting input end of the operational amplifier, and the voltage of MOS tubes 1-2 is fed back to the non-inverting input end of the operational amplifier. Therefore, the operational amplifier, the first Hall sensor and MOS tubes 1-2 constitute a negative feedback regulation. According to the virtual short and virtual open characteristics of the operational amplifier, the control voltage of the input end Vcm is unchanged, so that the output voltage of the first Hall sensor is forced to be equal to the voltage of the input end Vcm. In this way, the voltage signal input by the input end Vcm is equal to the output voltage signal of the operational amplifier, that is, the voltage signal input by the input end Vcm is given to the gate of MOS tubes M1-M2. At this time, the voltage at point A of the drain of MOS tube M1 is equal to the voltage at point B of the drain of MOS tube M2. By controlling the voltages at points A and B, the voltages at each node of the first Hall sensor and the MOS tube in the four-phase rotating current circuit can be adjusted, so that the output common-mode voltage signal of the first Hall sensor returns to a stable value and is equal to the output common-mode voltage of the second Hall sensor.

[0023] The four-phase rotating current circuit comprises MOS tubes MN1-12, MOS tubes MP1-4, an output terminal Vout1 and an output terminal Vout2, the N pole of the first Hall sensor is connected with the drain of the MOS tube MN1, the source of the MOS tube MN2, the drain of the MOS tube MP1 and the drain of the MOS tube MN3 respectively, the W pole of the first Hall sensor is connected with the drain of the MOS tube MN4, the source of the MOS tube MN5, the drain of the MOS tube MP2 and the drain of the MOS tube MN6 respectively, the S pole of the first Hall sensor is connected with the drain of the MOS tube MP3, the drain of the MOS tube MN7, the drain of the MOS tube MN8 and the source of the MOS tube MN9 respectively, the E pole of the first Hall sensor is connected with the drain of the MOS tube MP4, the drain of the MOS tube MN10, the drain of the MOS tube MN11 and the source of the MOS tube MN12 respectively, the drain of the MOS tube MN2, the drain of the MOS tube MN5, the drain of the MOS tube MN9 and the drain of the MOS tube MN12 output a common-mode voltage signal through the output terminal Vout1, the source of the MOS tube MN3, the source of the MOS tube MN4, the source of the MOS tube MN7 and the source of the MOS tube MN11 output a common-mode voltage signal through the output terminal Vout2, and the gates of the MOS tubes MN1-12 and the MOS tubes MP1-4 receive clock signals respectively.

[0024] The bias circuit comprises a bias current source I0, a Hall sensor bias current source Ibias and MOS tubes M7-13, the bias current source I0 is connected with the drain of the MOS tube M7, the gate of the MOS tube M7, the gate of the MOS tube M8, the gate of the MOS tube M10 and the gate of the MOS tube M12 in sequence, the Hall sensor bias current source Ibias is connected with the drain of the MOS tube M8, the gate of the MOS tube M9, the gate of the MOS tube M11 and the gate of the MOS tube M13 in sequence, the source of the MOS tube M8 is connected with the drain of the MOS tube M9, the source of the MOS tube M10 is connected with the drain of the MOS tube M11, the source of the MOS tube M12 is connected with the drain of the MOS tube M13, the drain of the MOS tube M10 is connected with the source of the MOS tube M5, the bias current source I0 makes the MOS tube M7, the MOS tube M8, the MOS tube M10 and the MOS tube M12 work in the saturation region, the gate of the MOS tube M9, the gate of the MOS tube M11 and the gate of the MOS tube M13, and the Hall sensor bias current source Ibias makes the MOS tube M9, the MOS tube M11 and the MOS tube M13 work in the saturation region, according to the principle that the MOS tubes working in the saturation region and having the same gate-source voltage transmit the same current, the current flowing through M10 and M11 is equal to the current flowing through M8 and M9, and the current flowing through M12 and M13 is also equal to the current flowing through M8 and M9, so that the bias circuit can accurately copy the current of the reference current source Ibias as the bias current of the first Hall device and the second Hall device.

[0025] Embodiment one: based on the above-mentioned one kind of Hall sensor signal unbalance correction circuit structure, as shown inFigure 2 As shown, MOS tube M1~3 is P-type MOS tube, MOS tube M4~13 is N-type MOS tube, the power supply voltage is provided for the four-phase rotating current circuit and the first Hall sensor through MOS tube M1, the drain of MOS tube M1~2 is connected with MOS tube MP1~4, the power supply voltage is provided for the second Hall sensor through MOS tube M2~3 in turn, the N pole of the second Hall sensor is connected with the drain of MOS tube M3, the S pole of the second Hall sensor is connected with MOS tube M4;

[0026] The Hall device bias current source Ibias provides stable voltage for the gate of MOS tube M9, the gate of MOS tube M11 and the gate of MOS tube M13, so that MOS tube M9, MOS tube M11 and MOS tube M13 are turned on, the bias current source I0 is grounded through MOS tube M7, the Hall sensor bias current source Ibias is grounded through MOS tube M8~9 in turn, the four-phase rotating current circuit is grounded through MOS tube M12~13 in turn, the second Hall sensor is grounded through MOS tube M10~11 in turn.

[0027] Embodiment two: based on a Hall sensor signal offset correction circuit structure, as shown in Figure 3 As shown, MOS tube M1, MOS tube M2 and MOS tube M5 are N-type MOS tubes, MOS tube M3, MOS tube M4, MOS tube M6~13 are P-type MOS tubes, the bias current source I0 provides stable voltage for the gate of MOS tube M7, the gate of MOS tube M8, the gate of MOS tube M10 and the gate of MOS tube M12, so that MOS tube M7, MOS tube M8, MOS tube M10 and MOS tube M12 are turned on, the Hall device bias current source Ibias provides stable voltage for the gate of MOS tube M9, the gate of MOS tube M11 and the gate of MOS tube M13, so that MOS tube M9, MOS tube M11 and MOS tube M13 are turned on, the four-phase rotating current circuit is grounded through MOS tube M1, MOS tube M1 is connected with MOS tube MN1, MOS tube MN6, MOS tube MN8 and MOS tube MN10 respectively, the second Hall sensor is grounded through MOS tube 2~3, the S pole of the second Hall sensor is connected with the drain of MOS tube M3, the N pole of the second Hall sensor is connected with the drain of MOS tube M4;

[0028] MOS transistor M13 is connected with MOS transistor MP1~4 respectively, power voltage provides current for four-phase rotating current circuit and first Hall sensor through MOS transistor M12~13 in turn, power voltage provides current for second Hall sensor through MOS transistor M10~11 and MOS transistor M4 in turn, power voltage is connected with bias current source Ibias of Hall sensor through MOS transistor M8~9 in turn, current outflow end of bias current source Ibias of Hall sensor is grounded, power voltage is connected with bias current source I0 through MOS transistor M7, current outflow end of bias current source I0 is grounded, in this embodiment, power voltage transmits current to MOS transistor M7~9, but current of MOS transistor M7~9 is controlled through bias current source I0 and bias current source Ibias of Hall sensor, namely bias current source I0 and bias current source Ibias of Hall sensor provide bias current.

[0029] All P-type MOS transistors in the application are of the same size, and all N-type MOS transistors are also of the same size.

[0030] The above description is only the preferred embodiment of the present application, and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A circuit structure for correcting distortion of the output signal of a Hall sensor, comprising a four-phase rotating current circuit, a first Hall sensor disposed within the four-phase rotating current circuit, a power supply voltage providing current to the four-phase rotating current circuit and the first Hall sensor, and a bias circuit providing bias current to the four-phase rotating current circuit and the first Hall sensor, characterized in that: The power supply voltage is also connected to a common-mode voltage correction circuit for correcting the common-mode voltage of the first Hall sensor. The common-mode voltage correction circuit includes an input terminal Vcm, an operational amplifier, MOSFETs M1 to M6, and a second Hall sensor. The power supply voltage provides current to the four-phase rotating current circuit through MOSFET M1, and provides current to the second Hall sensor through MOSFETs M2 to M3. The gate of MOSFET M3 is grounded. The second Hall sensor is connected to the bias circuit through MOSFET M4. MOSFETs M5 to M6 are respectively connected to the W and E terminals of the second Hall sensor. The input terminal Vcm inputs a control voltage signal, which is the common-mode voltage output by the four-phase rotating current circuit, to the inverting input terminal of the operational amplifier. The second Hall sensor is connected to the non-inverting input terminal of the operational amplifier through MOS transistors M5-6. The output terminal of the operational amplifier is connected to the non-inverting input terminal of the operational amplifier through a capacitor. The output terminal of the operational amplifier is connected to the gate of MOS transistors M1-2 respectively, and the drain of MOS transistor M1 and the drain of MOS transistor M2 are connected.

2. The circuit structure for correcting distortion of the output signal of a Hall sensor according to claim 1, characterized in that: The four-phase rotating current circuit includes MOSFETs MN1-12, MOSFETs MP1-4, output terminals Vout1 and Vout2. The N-terminal of the first Hall sensor is connected to the drain of MOSFET MN1, the source of MOSFET MN2, the drain of MOSFET MP1, and the drain of MOSFET MN3. The W-terminal of the first Hall sensor is connected to the drain of MOSFET MN4, the source of MOSFET MN5, the drain of MOSFET MP2, and the drain of MOSFET MN6. The S-terminal of the first Hall sensor is connected to the drain of MOSFET MP3, the drain of MOSFET MN7, the drain of MOSFET MN8, and the source of MOSFET MN9. The emitter (E) of the first Hall sensor is connected to the drain of MOSFET MP4, the drain of MOSFET MN10, the drain of MOSFET MN11, and the source of MOSFET MN12. The drains of MOSFETs MN2, MN5, MN9, and MN12 output common-mode voltage signals through the output terminal Vout1. The sources of MOSFETs MN3, MN4, MN7, and MN11 output common-mode voltage signals through the output terminal Vout2. The gates of MOSFETs MN1-12 and MOSFETs MP1-4 receive clock signals respectively.

3. The circuit structure for correcting distortion of the output signal of a Hall sensor according to claim 2, characterized in that: The bias circuit includes a bias current source I0, a Hall sensor bias current source Ibias, and MOSFETs M7-M13. The bias current source I0 is sequentially connected to the drain of MOSFET M7, the gate of MOSFET M7, the gate of MOSFET M8, the gate of MOSFET M10, and the gate of MOSFET M12. The Hall sensor bias current source Ibias is sequentially connected to the drain of MOSFET M8, the gate of MOSFET M9, the gate of MOSFET M11, and the gate of MOSFET M13. The source of MOSFET M8 is connected to the drain of MOSFET M9. The source of MOSFET M10 is connected to the drain of MOSFET M11. The source of MOSFET M12 is connected to the drain of MOSFET M13. The sources of MOSFETs M7, M9, M11, and M13 are all grounded. The drain of MOSFET M10 is connected to the source of MOSFET M4.

4. The circuit structure for correcting distortion of the output signal of a Hall sensor according to claim 3, characterized in that: The MOSFETs M1-3 are P-type MOSFETs, and the MOSFETs M4-13 are N-type MOSFETs. The power supply voltage provides current to the four-phase rotating current circuit and the first Hall sensor through MOSFET M1. The drains of MOSFETs M1-2 are all connected to MOSFETs M1-4. The power supply voltage provides current to the second Hall sensor through MOSFETs M2-3 in sequence. The N-terminal of the second Hall sensor is connected to the drain of MOSFET M3, and the S-terminal of the second Hall sensor is connected to MOSFET M4. The source of MOSFET M12 is connected to the drains of MOSFETs MN1, MN6, MN8, and MN10, respectively. The bias current source I0 is grounded through MOSFET M7. The Hall sensor bias current source Ibias is grounded sequentially through MOSFETs M8 to M9. The four-phase rotating current circuit is grounded sequentially through MOSFETs M12 to M13. The second Hall sensor is grounded sequentially through MOSFETs M10 to M11.

5. The circuit structure for correcting distortion of the output signal of a Hall sensor according to claim 3, characterized in that: The MOSFETs M1, M2, and M5 are N-type MOSFETs, and the MOSFETs M3, M4, and M6-13 are P-type MOSFETs. The four-phase rotating current circuit is grounded through MOSFET M1. MOSFET M1 is connected to MOSFETs MN1, MN6, MN8, and MN10 respectively. The second Hall sensor is grounded through MOSFETs 2-3. The source (S) terminal of the second Hall sensor is connected to the drain of MOSFET M3, and the non-source (N) terminal of the second Hall sensor is connected to the drain of MOSFET M4. The MOSFET M13 is connected to MOSFETs MP1-4 respectively. The power supply voltage sequentially provides current to the four-phase rotating current circuit and the first Hall sensor through MOSFETs M12-13. The power supply voltage sequentially provides current to the second Hall sensor through MOSFETs M10-11 and MOSFET M4. The power supply voltage sequentially connects to the Hall sensor bias current source Ibias through MOSFETs M8-9. The current output terminal of the Hall sensor bias current source Ibias is grounded. The power supply voltage is connected to the bias current source I0 through MOSFET M7. The current output terminal of the bias current source I0 is grounded.

6. A circuit structure for correcting distortion of the output signal of a Hall sensor according to claim 4 or 5, characterized in that: The P-type MOS transistors mentioned above all have the same dimensions, as do the N-type MOS transistors mentioned above.

Images