Voltage output type closed-loop Hall sensor circuit using internal and external references

Abstract

The utility model discloses a voltage output type closed-loop Hall sensor circuit using internal and external references, and relates to the technical field of sensors. The circuit comprises an internal reference voltage source, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor, a second capacitor, a first operational amplifier, a second operational amplifier, an inductor and a plurality of external pins. According to the utility model, a built-in voltage reference scheme can be used, an external voltage reference can also be used, the requirements on external voltage reference impedance and a connecting line are low, and the built-in voltage reference is completely compatible, so that a more convenient and simpler system design and more accurate measurement precision are ensured; the use convenience and the measurement accuracy of the sensor can be improved by using both the external reference and the internal reference.

Description

Technical Field

[0001] The utility model belongs to the technical field of sensors, and in particular relates to a voltage output type closed-loop Hall sensor circuit using internal and external references. Background Art

[0002] A voltage output closed-loop Hall sensor is an electronic device used to measure magnetic field strength. Its output is a continuous voltage signal that is usually proportional to the strength of the measured magnetic field.

[0003] Voltage-output closed-loop Hall effect sensor circuits require a voltage reference for measurement. Existing technologies only offer a built-in voltage reference option, which places high demands on measurement system wiring and design. Users must also continuously measure the voltage reference, which takes up extra measurement time and can easily introduce additional measurement errors. Utility Model Content

[0004] The purpose of this utility model is to provide a voltage output closed-loop Hall effect sensor circuit using internal and external references, which can be achieved through the following technical solutions:

[0005] The embodiment of the present application provides a voltage output type closed-loop Hall sensor circuit using an internal and external reference, comprising an internal reference voltage source, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor, a second capacitor, a first operational amplifier, a second operational amplifier, an inductor, a Hall sensor, an amplifier, and a plurality of external pins;

[0006] One end of the first resistor is connected to an internal reference voltage source, and the other end is connected to one end of the second resistor; the other end of the first resistor is also connected to one end of the first capacitor, and the connection point of the two is connected to the non-inverting input terminal of the first operational amplifier; the other end of the first capacitor is grounded; the inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier, and the connection point of the two is connected to one end of the third resistor; the other end of the third resistor is connected to one end of the fourth resistor and then to the non-inverting input terminal of the second operational amplifier; the inverting input terminal of the second operational amplifier is connected to one end of the fifth resistor and then to one end of the sixth resistor, and the other end of the sixth resistor is connected to the output terminal of the second operational amplifier and then to the third pin of the external pins;

[0007] The other end of the second resistor is connected to one end of the second capacitor, and the connection point between the two is further connected to the fourth pin of the external pin; the other end of the second capacitor is grounded;

[0008] One end of the inductor is connected to the other end of the fourth resistor and then to one end of the seventh resistor; the other end of the inductor is connected to the amplifier and then to the other end of the seventh resistor, and the connection point is connected to the other end of the fifth resistor;

[0009] The amplifier is also connected to the Hall sensor.

[0010] Preferably, the plurality of external pins further include a first pin, a second pin and a fifth pin.

[0011] Preferably, the first pin is a Vc pin; the second pin is a GND pin; the third pin is a Vout pin; the fourth pin is a Vref pin; and the fifth pin is an NC pin.

[0012] Preferably, the fourth pin is connected to an external application circuit; the external application circuit is used to provide an external voltage reference.

[0013] Preferably, the resistance of the first resistor is 10 kΩ; the resistance of the second resistor is 100 Ω.

[0014] Preferably, the capacitance value of the first capacitor is 100 pF; the capacitance value of the second capacitor is 100 nF.

[0015] The beneficial effects of the present invention are as follows: in addition to being able to use the built-in voltage reference solution, the present invention can also use an external voltage reference, has low requirements on the external voltage reference impedance and connection lines and is fully compatible with the use of the built-in voltage reference, so as to ensure a more convenient and simple system design and more accurate measurement accuracy; the use of both external and internal references improves the convenience of use and measurement accuracy of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] For better understanding and implementation, the technical solution of the present application is described in detail below with reference to the accompanying drawings.

[0017] Figure 1 A schematic diagram of a closed-loop Hall sensor circuit with voltage output using internal and external references provided in an embodiment of the present application;

[0018] Description of Reference Numerals

[0019] In the figure: 1, first pin; 2, second pin; 3, third pin; 4, fourth pin; 5, fifth pin; 6, Hall sensor; 7, amplifier. DETAILED DESCRIPTION

[0020] To further illustrate the technical means and effectiveness of the present invention in achieving its intended purpose, exemplary embodiments are described in detail herein, as illustrated in the accompanying drawings. In the following description, unless otherwise indicated, identical numerals in different figures represent identical or similar elements. The embodiments described in the following exemplary embodiments are not intended to represent all possible implementations consistent with the present application. Rather, they are merely examples of methods and systems consistent with certain aspects of the present application, as detailed in the appended claims.

[0021] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms "a," "an," "the," and "the" used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to any or all possible combinations of one or more of the associated listed items.

[0022] The following describes in detail the specific implementation methods, features and effects of the present invention in conjunction with the accompanying drawings and preferred embodiments.

[0023] See also Figure 1 The embodiment of the present application provides a voltage output closed-loop Hall sensor circuit using an internal and external reference, including an internal reference voltage source V1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a first capacitor C1, a second capacitor C2, a first operational amplifier U1, a second operational amplifier U2, an inductor L1, a Hall sensor 6, an amplifier 7, and multiple external pins;

[0024] One end of the first resistor R1 is connected to the internal reference voltage source V1, and the other end is connected to one end of the second resistor R2; the other end of the first resistor R1 is also connected to one end of the first capacitor C1, and the connection point of the two is connected to the non-inverting input terminal of the first operational amplifier U1; the other end of the first capacitor C1 is grounded; the inverting input terminal of the first operational amplifier U1 is connected to its output terminal, and the connection point of the two is connected to one end of the third resistor R3; the other end of the third resistor R3 is connected to one end of the fourth resistor R4 and then to the non-inverting input terminal of the second operational amplifier U2; the inverting input terminal of the second operational amplifier U2 is connected to one end of the fifth resistor R5 and then to one end of the sixth resistor R6, and the other end of the sixth resistor R6 is connected to the output terminal of the second operational amplifier U2 and then to the third pin 3 among the external pins;

[0025] The other end of the second resistor R2 is connected to one end of the second capacitor C2, and the connection point between the two is further connected to the fourth pin 4 of the external pin; the other end of the second capacitor C2 is grounded;

[0026] One end of the inductor L1 is connected to the other end of the fourth resistor R4 and then to one end of the seventh resistor R7. The other end of the inductor L1 is connected to the amplifier 7 and then to the other end of the seventh resistor R7. The connection point is then connected to the other end of the fifth resistor R5.

[0027] The amplifier 7 is also connected to the Hall sensor 6 .

[0028] In an embodiment provided in the present application, the plurality of external pins further include a first pin 1 , a second pin 2 and a fifth pin 5 .

[0029] In an embodiment provided in the present application, the first pin 1 is a Vc pin; the second pin 2 is a GND pin; the third pin 3 is a Vout pin; the fourth pin 4 is a Vref pin; and the fifth pin 5 is an NC pin; wherein the fourth pin 4 is connected to an external application circuit; and the external application circuit is used to provide an external voltage reference.

[0030] Specifically, among the multiple external pins of this embodiment, the Vc pin (power supply pin) is a pin for power supply, which is connected to the power supply voltage to provide the required electrical energy for the circuit; the GND pin (ground pin) is the ground wire of the circuit, which is connected to the ground of the circuit to provide a potential reference point; the Vout pin (output pin) is the output voltage pin of the circuit, which outputs the processed voltage; the Vref pin (reference voltage pin) is used to provide a reference voltage for comparing or adjusting other voltages; the NC pin (no connection pin) indicates that the pin is not used in the circuit and is a pin reserved for compatibility with other versions or for physical layout needs. The NC pin should not be connected to any circuit.

[0031] In an embodiment provided in the present application, the first resistor R1>>the second resistor R2, specifically: the resistance of the first resistor (R1) is 10kΩ; the resistance of the second resistor (R2) is 100Ω.

[0032] Specifically, in this embodiment, 10 kΩ=10000 Ω, so the resistance of the first resistor R1 is much greater than that of the second resistor R2 , and the former is 100 times that of the latter.

[0033] In an embodiment provided in the present application, the capacitance value of the first capacitor C1 is 100 pF; the capacitance value of the second capacitor C2 is 100 nF.

[0034] Specifically, pF represents picofarad, nF represents nanofarad, and 100pF=0.1nF.

[0035] The working principle of this utility model is as follows:

[0036] like Figure 1As shown, the present invention provides a voltage-output closed-loop Hall effect sensor circuit that can use both an internal and external voltage reference. A second operational amplifier (U2) performs voltage amplification and level shifting. The required reference voltage is provided by an internal voltage reference source (V1) or an external voltage reference from an external application circuit (provided via the Vref pin), buffered by the first operational amplifier (U1). The first operational amplifier (U1) is a high-precision operational amplifier (HPA) to ensure that the accuracy of the reference voltage is not affected.

[0037] When using the internal voltage reference, the internal reference voltage provided by the internal reference voltage source V1 is provided to the first operational amplifier U1 through the first resistor R1 and, after being buffered, is provided to the second operational amplifier U2 through the third resistor R3 for biasing. On the other hand, it is connected to the fourth pin 4 (Vref pin) through the first resistor R1 and the second resistor R2 to the sensor application circuit to measure its voltage value and perform AD conversion. The external application circuit will also measure the output of the sensor's third pin 3, perform AD conversion, and calculate the difference between the two conversion values ​​to obtain the sensor measurement result.

[0038] When using an external voltage reference, since the resistance of the first resistor R1 is much greater than the resistance of the second resistor R2, the voltage at the non-inverting input of the first operational amplifier U1 is provided by the external voltage reference provided by the external application circuit and determined by the fourth pin 4. Therefore, it can be ensured that the sensor can use the external reference voltage at this time. At this time, the external application circuit will AD convert the voltage value of the external voltage reference it provides, and will also measure the output of the third pin 3 of the sensor and perform AD conversion and calculate the difference between the two conversion values ​​to obtain the sensor measurement result.

[0039] It should be noted that the first capacitor C1 and the second capacitor C2 are used to absorb various interferences from the circuit connected to the external Vref pin of the product.

[0040] It can be understood that in addition to maintaining the built-in voltage reference solution provided by the prior art, the present invention can also use an external voltage reference, which has low requirements for the external voltage reference impedance and connection lines and is fully compatible with the use of the built-in voltage reference, so as to ensure more convenient and simple system design and more accurate measurement accuracy.

[0041] It's important to note that a reference voltage is a stable voltage value used as a comparison or reference point. It's often used as a standard voltage for comparison and to set other voltages as a reference. Its characteristics are: the reference voltage can be provided externally (e.g., by an external application circuit) or generated internally by the circuit. A voltage reference, on the other hand, refers to a dedicated circuit or device that provides a stable reference voltage, such as a voltage reference chip. While a reference voltage focuses on the voltage value and its application in a circuit, a voltage reference emphasizes the specific device or circuit that provides this stable voltage.

[0042] In the present application, the external application circuit can provide an external voltage reference, and the external voltage reference can provide an external reference voltage.

[0043] The voltage output closed-loop Hall sensor circuit using internal and external references provided by the present invention is applied to a voltage output closed-loop Hall sensor. Through the circuit, users can use both external and internal references, thereby improving the convenience of use and measurement accuracy of the sensor.

[0044] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0045] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A closed-loop Hall effect sensor circuit with voltage output using an internal or external reference, characterized in that: The device comprises an internal reference voltage source (V1), a first resistor (R1), a second resistor (R2), a third resistor (R3), a fourth resistor (R4), a fifth resistor (R5), a sixth resistor (R6), a seventh resistor (R7), a first capacitor (C1), a second capacitor (C2), a first operational amplifier (U1), a second operational amplifier (U2), an inductor (L1), a Hall sensor (6), an amplifier (7), and a plurality of external pins; One end of the first resistor (R1) is connected to an internal reference voltage source (V1), and the other end is connected to one end of the second resistor (R2); the other end of the first resistor (R1) is also connected to one end of the first capacitor (C1), and the connection point between the two is connected to the non-inverting input terminal of the first operational amplifier (U1); The other end of the first capacitor (C1) is grounded; the inverting input end of the first operational amplifier (U1) is connected to its output end, and the connection point between the two is connected to one end of a third resistor (R3); the other end of the third resistor (R3) is connected to one end of a fourth resistor (R4) and then to the non-inverting input end of a second operational amplifier (U2); the inverting input end of the second operational amplifier (U2) is connected to one end of a fifth resistor (R5) and then to one end of a sixth resistor (R6), and the other end of the sixth resistor (R6) is connected to the output end of the second operational amplifier (U2) and then to the third pin (3) among the external pins; The other end of the second resistor (R2) is connected to one end of the second capacitor (C2), and the connection point between the two is further connected to the fourth pin (4) among the external pins; the other end of the second capacitor (C2) is grounded; One end of the inductor (L1) is connected to the other end of the fourth resistor (R4) and then to one end of the seventh resistor (R7); the other end of the inductor (L1) is connected to the amplifier (7) and then to the other end of the seventh resistor (R7), and the connection point is connected to the other end of the fifth resistor (R5); The amplifier (7) is also connected to the Hall sensor (6).

2. The voltage output closed-loop Hall sensor circuit using internal and external references according to claim 1, characterized in that: The plurality of external pins further include a first pin (1), a second pin (2) and a fifth pin (5).

3. The voltage output closed-loop Hall sensor circuit using internal and external references according to claim 2, characterized in that: The first pin (1) is a Vc pin; the second pin (2) is a GND pin; the third pin (3) is a Vout pin; the fourth pin (4) is a Vref pin; and the fifth pin (5) is an NC pin.

4. The voltage output closed-loop Hall sensor circuit using internal and external references according to claim 3, characterized in that: The fourth pin (4) is connected to an external application circuit; the external application circuit is used to provide an external voltage reference.

5. The voltage output closed-loop Hall sensor circuit using internal and external references according to claim 1, characterized in that: The resistance of the first resistor (R1) is 10kΩ; the resistance of the second resistor (R2) is 100Ω.

6. The voltage output closed-loop Hall sensor circuit using internal and external references according to claim 1, characterized in that: The capacitance value of the first capacitor (C1) is 100pF; the capacitance value of the second capacitor (C2) is 100nF.

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