Self-adaptive wide-temperature scene temperature compensation circuit and compensation method thereof

Abstract

The invention discloses a temperature compensation circuit adaptive to a wide-temperature scene and a compensation method thereof, and the circuit comprises a first temperature compensation network which comprises a first divider resistor, a first thermosensitive branch circuit and a first switch element which are connected in series; the second temperature compensation network comprises a second divider resistor, a second thermosensitive branch and a second switch element which are connected in series, and the resistance value of the first thermistor is smaller than that of the second thermistor; the control unit is connected with the first temperature compensation network and the second temperature compensation network, and is used for collecting a partial pressure value of a thermosensitive branch in the currently started temperature compensation network, and determining a temperature value of a thermistor in the current temperature compensation network based on the partial pressure value; the temperature value is compared with the preset temperature compensation interval, the temperature compensation network matched with the current temperature value is started to carry out temperature compensation on output of the sensor, the temperature compensation network can be flexibly switched, accurate temperature compensation is carried out by being matched with a wide-temperature scene, and stable output of the sensor is ensured.

Description

Technical Field

[0001] This application belongs to the field of sensor technology, specifically relating to an adaptive temperature compensation circuit and compensation method for wide-temperature scenarios. Background Technology

[0002] In complex environments such as industrial control and automotive electronics, proximity sensors need to operate stably over long periods in environments with extremely wide temperature ranges. Their detection accuracy and output stability directly affect the safety and efficiency of equipment operation. Traditional proximity sensors often rely on materials such as epoxy resin and polyurethane for encapsulation or protection. Under high or low temperature environments, these materials are prone to aging and deformation, which can lead to circuit parameter drift, resulting in decreased sensor detection accuracy or even complete failure, making it difficult to meet the needs of use in wide-temperature scenarios.

[0003] In the development of wide-temperature sensors, temperature compensation circuits are crucial. Most related technologies use a temperature compensation network composed of a single NTC (Negative Temperature Coefficient Thermistor) to compensate for the temperature of the sensor. However, its effective temperature range is limited by the physical properties of the thermosensitive material, making it difficult to cope with a wide temperature range. This can lead to compensation failure in the high-temperature region or overcompensation in the low-temperature region, which cannot meet the stability requirements of precision ranging and safety control systems.

[0004] Therefore, how to solve the performance failure of proximity sensors in working scenarios with extremely wide temperature ranges and ensure their stable output in harsh environments is an urgent problem to be solved. Summary of the Invention

[0005] This application provides an adaptive temperature compensation circuit and method for wide-temperature scenarios, which can flexibly switch the temperature compensation network to adapt to wide-temperature scenarios for accurate temperature compensation and ensure stable sensor output.

[0006] To address the aforementioned technical problems, this application provides an adaptive temperature compensation circuit for wide-temperature scenarios, comprising:

[0007] The first temperature compensation network includes a first voltage divider resistor, a first thermistor branch, and a first switching element for controlling the activation state of the first temperature compensation network, wherein the first thermistor branch includes a first thermistor and a first matching resistor connected in parallel.

[0008] The second temperature compensation network includes a second voltage divider resistor, a second thermistor branch, and a second switching element for controlling the activation state of the second temperature compensation network, wherein the second thermistor branch includes a second thermistor and a second matching resistor connected in parallel, and the first thermistor is less than the resistance value of the second thermistor.

[0009] The control unit, connected to the first temperature compensation network and the second temperature compensation network, is used to collect the voltage division value of the thermistor branch in the currently enabled temperature compensation network, and determine the temperature value of the thermistor in the current temperature compensation network based on the voltage division value.

[0010] The control unit is also used to compare the temperature value with a preset temperature compensation range, and switch the conduction state of the first switching element and the second switching element according to the comparison result, so as to enable the temperature compensation network adapted to the current temperature value to perform temperature compensation on the sensor output.

[0011] As a further improvement of this application, the first thermistor branch further includes a first compensation resistor and a first adjustable resistor. The first thermistor and the first matching resistor are connected together and then connected to the first compensation resistor. The first adjustable resistor is connected in parallel across the first thermistor and the first compensation resistor.

[0012] And / or, the second thermistor branch further includes a second compensation resistor and a second adjustable resistor, the second thermistor and the second matching resistor are connected together and then connected to the second compensation resistor, and the second adjustable resistor is connected in parallel across the second thermistor and the second compensation resistor.

[0013] As a further improvement of this application, the first switching element is a first MOS transistor, a first connection resistor is provided between the drain of the first MOS transistor and the first thermistor branch, the source of the first MOS transistor is grounded, and the gate of the first MOS transistor is connected to the control unit after being connected to the first gate resistor.

[0014] And / or, the second switching element is a second MOSFET, a second connection resistor is provided between the drain of the second MOSFET and the second thermistor branch, the source of the second MOSFET is grounded, and the gate of the second MOSFET is connected to the control unit after being connected to the second gate resistor.

[0015] As a further improvement of this application, one end of the first voltage divider resistor and the second voltage divider resistor is connected to the power supply voltage, and the sampling pin of the control unit is connected between the first voltage divider resistor and the first thermistor branch, and between the second voltage divider resistor and the second thermistor branch.

[0016] As a further improvement of this application, the control unit is used to compare the temperature value with a preset first temperature compensation interval and a preset second temperature compensation interval, and determine whether the temperature value is within the preset first temperature compensation interval or the preset second temperature compensation interval.

[0017] When the temperature value is within the first temperature compensation range, the first switching element is turned on and the second switching element is turned off, and the first temperature compensation network is enabled to perform temperature compensation on the sensor output.

[0018] When the temperature value is within the second temperature compensation range, the second switching element is turned on and the first switching element is turned off, enabling the second temperature compensation network to perform temperature compensation on the sensor output.

[0019] As a further improvement of this application, the upper limit of the first temperature compensation interval does not exceed the lower limit of the second temperature compensation interval.

[0020] As a further improvement of this application, the resistance of the first thermistor is 10kΩ, and the first temperature compensation range is (-40℃~10℃).

[0021] The resistance of the second thermistor is 22kΩ, and the second temperature compensation range is [10℃~100℃].

[0022] As a further improvement of this application, the resistance value of the first voltage divider resistor is less than the resistance value of the second voltage divider resistor, and the resistance value of the first matching resistor is less than the resistance value of the second matching resistor.

[0023] Based on the above-mentioned adaptive wide-temperature scenario temperature compensation circuit, this application also provides an adaptive wide-temperature scenario temperature compensation method, including the following steps:

[0024] Collect the voltage drop value of the thermistor circuit in the currently enabled temperature compensation network;

[0025] The temperature value of the thermistor in the current temperature compensation network is determined based on the voltage divider value.

[0026] The temperature value is compared with a preset first temperature compensation range and a second temperature compensation range;

[0027] Based on the comparison results, the conduction states of the first and second switching elements are switched to enable a temperature compensation network adapted to the current temperature value to perform temperature compensation on the sensor output.

[0028] As a further improvement of this application, the step of switching the conduction states of the first switching element and the second switching element according to the comparison result to enable a temperature compensation network adapted to the current temperature value to perform temperature compensation for the sensor output includes:

[0029] Determine whether the temperature value is within the preset first temperature compensation range or the second temperature compensation range;

[0030] When the temperature value is within the first temperature compensation range, the first switching element is turned on and the second switching element is turned off, and the first temperature compensation network is enabled to perform temperature compensation on the sensor output.

[0031] When the temperature value is within the second temperature compensation range, the second switching element is turned on and the first switching element is turned off, enabling the second temperature compensation network to perform temperature compensation on the sensor output.

[0032] The adaptive wide-temperature scenario temperature compensation circuit and its compensation method provided in this application have the following beneficial effects:

[0033] This application sets up a first temperature compensation network and a second temperature compensation network covering different temperature compensation ranges. The control unit collects the voltage signal of the currently activated first or second temperature compensation network, determines the resistance value of the currently activated first or second thermistor and the current temperature value based on the voltage signal, compares the current temperature value with a preset temperature compensation range, and switches the conduction state of the first and second switching elements according to the comparison result, so as to activate the temperature compensation network corresponding to the currently conducting switching element for temperature compensation. This application flexibly switches the appropriate temperature compensation network according to the current real-time temperature value for accurate temperature compensation, avoiding the parameter drift phenomenon that occurs in traditional single thermistors over a wide temperature range, and ensuring that the sensor can still output stably under a large temperature span. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only a part of the embodiments of this application, and not all of the embodiments. For those skilled in the art, other drawings obtained from these drawings without creative effort are all within the scope of protection of this application.

[0035] Figure 1 This is a schematic diagram of the adaptive wide-temperature scenario temperature compensation circuit provided in the embodiments of this application;

[0036] Figure 2 This is a schematic diagram of the structure of the first thermistor branch in the temperature compensation circuit for adaptive wide-temperature scenarios provided in the embodiments of this application;

[0037] Figure 3 This is a schematic diagram of the structure of the second thermistor branch in the temperature compensation circuit for adaptive wide-temperature scenarios provided in the embodiments of this application;

[0038] Figure 4 This is a circuit diagram of the temperature compensation circuit for adaptive wide-temperature scenarios provided in the embodiments of this application;

[0039] Figure 5 This is a circuit diagram of the control unit in the temperature compensation circuit for adaptive wide-temperature scenarios provided in this application embodiment;

[0040] Figure 6 This is a flowchart of the temperature compensation method for adaptive wide-temperature scenarios provided in the embodiments of this application;

[0041] Figure 7 This is a flowchart of the switching of the conduction state of the switching element in the temperature compensation method for adaptive wide-temperature scenarios provided in the embodiments of this application. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0043] To make the description of this disclosure more detailed and complete, illustrative descriptions of the implementation methods and specific embodiments of this application are provided below; however, this is not the only form of implementing or utilizing the specific embodiments of this application. The implementation methods cover the features of multiple specific embodiments and the method steps and their order for constructing and operating these specific embodiments. However, other specific embodiments can also be used to achieve the same or equivalent functions and step sequences. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0045] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The word "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more. Other quantifiers should be understood similarly. The preferred embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. Furthermore, the embodiments of this application and the features in the embodiments can be combined with each other without conflict.

[0046] In complex environments such as industrial control and automotive electronics, proximity sensors need to operate stably over long periods in environments with extremely wide temperature ranges. Their detection accuracy and output stability directly affect the safety and efficiency of equipment operation. Traditional proximity sensors often rely on materials such as epoxy resin and polyurethane for encapsulation or protection. Under high or low temperature environments, these materials are prone to aging and deformation, which can lead to circuit parameter drift, resulting in decreased sensor detection accuracy or even complete failure, making it difficult to meet the needs of use in wide-temperature scenarios.

[0047] In the development of wide-temperature sensors, temperature compensation circuits are crucial. Most related technologies use a temperature compensation network composed of a single NTC resistor to compensate for the temperature of the sensor. However, its effective temperature range is limited by the physical properties of the thermistor material, making it difficult to cope with a wide temperature range. This can lead to compensation failure in the high-temperature region or overcompensation in the low-temperature region, which cannot meet the stability requirements of precision ranging and safety control systems.

[0048] Therefore, how to solve the performance failure of proximity sensors in working scenarios with extremely wide temperature ranges and ensure their stable output in harsh environments is an urgent problem to be solved.

[0049] In view of this, please refer to Figures 1-7 This application proposes an adaptive temperature compensation circuit and method for wide-temperature scenarios, which can flexibly switch the temperature compensation network to adapt to wide-temperature scenarios for accurate temperature compensation and ensure stable output of the sensor.

[0050] Please refer to Figure 1 This is a schematic diagram of the structure of the temperature compensation circuit for adaptive wide-temperature scenarios provided in the embodiments of this application. The temperature compensation circuit includes a first temperature compensation network, a second temperature compensation network, and a control unit connected to the first temperature compensation network and the second temperature compensation network.

[0051] As an optional implementation, the first temperature compensation network includes a first voltage divider resistor, a first thermistor branch, and a first switching element for controlling the activation state of the first temperature compensation network, all connected in series. The first thermistor branch includes a first thermistor and a first matching resistor connected in parallel.

[0052] The second temperature compensation network includes a second voltage divider resistor, a second thermistor branch, and a second switching element for controlling the activation state of the second temperature compensation network, all connected in series. The second thermistor branch includes a second thermistor and a second matching resistor connected in parallel, and the resistance of the first thermistor is smaller than that of the second thermistor.

[0053] Furthermore, the aforementioned control unit is used to acquire the voltage division value of the thermistor branch in the currently enabled temperature compensation network, and determine the temperature value of the thermistor in the current temperature compensation network based on the voltage division value; the control unit is also used to compare the temperature value with a preset temperature compensation range, and switch the conduction state of the first switching element and the second switching element according to the comparison result, so as to enable the temperature compensation network corresponding to the currently conducting switching element to perform temperature compensation for the sensor output.

[0054] In this embodiment, the resistance of the first thermistor is set to be less than that of the second thermistor. Since the resistance of the NTC resistor decreases as the temperature increases, the first thermistor with a smaller resistance value has a very small resistance value in the high temperature region, which is close to a short circuit, while its resistance value is relatively large in the low temperature region, resulting in high sensitivity. On the other hand, the second thermistor with a larger resistance value has a very large resistance value in the low temperature region, which is close to an open circuit, while its resistance value is relatively moderate in the high temperature region, which can effectively compensate for the short circuit.

[0055] Therefore, this application divides the temperature compensation range that the temperature compensation network can achieve into two relative compensation intervals, with the first temperature compensation network performing compensation in the preset first temperature compensation interval and the second temperature compensation network performing compensation in the preset second temperature compensation interval.

[0056] For ease of understanding, the first temperature compensation zone can be understood as the low temperature zone and the second temperature compensation zone as the high temperature zone. However, the terms "low temperature" and "high temperature" here are only relative terms for the two zones and do not specifically refer to extreme high or low temperature environments. Those skilled in the art should be aware of this.

[0057] Specifically, by using a first temperature compensation network and a second temperature compensation network to cover different temperature compensation ranges, the first temperature compensation network and the second temperature compensation network form complementary temperature response characteristics.

[0058] In the first temperature compensation network, a first voltage divider resistor and a first thermistor branch are set to divide the voltage, converting the resistance change of the first thermistor in the first thermistor branch into an acquireable voltage signal. A first matching resistor is set in parallel with the first thermistor to correct the nonlinear characteristics of the first thermistor, thereby expanding the effective temperature compensation range that the first temperature compensation network can achieve. The first switching element is used to switch the corresponding first temperature compensation network on and off.

[0059] Similarly, in the second temperature compensation network, a second voltage divider resistor and a second thermistor branch are set to divide the voltage, converting the resistance change of the second thermistor in the second thermistor branch into an acquireable voltage signal. A second matching resistor is set in parallel with the second thermistor to correct the nonlinear characteristics of the second thermistor, expanding the effective temperature compensation range that the second temperature compensation network can achieve. The second switching element realizes the switching of the corresponding second temperature compensation network, further realizing the switching between the first and second temperature compensation networks under different temperature compensation ranges. Thus, the dual temperature compensation network covers a wide temperature range that a single thermistor cannot simultaneously cover.

[0060] Furthermore, the control unit determines the voltage division value of the thermistor branch in the currently activated temperature compensation network based on the voltage signal collected in the first or second temperature compensation network, and determines the temperature value of the thermistor in the current temperature compensation network based on the voltage division value.

[0061] It is understandable that the control unit collects the voltage signal of the currently active temperature compensation network, rather than collecting the voltage signals of two temperature compensation networks at the same time, because only one temperature compensation network is in the conducting state at any given time.

[0062] Taking the conduction of the first switching element in the first temperature compensation network as an example, the control unit collects the voltage signal in the first temperature compensation network, determines the voltage division value of the first thermistor branch in the first temperature compensation network based on the voltage signal, determines the resistance value of the first thermistor in the first temperature compensation network based on the voltage division value, and then, based on the temperature resistance characteristics of the thermistor, reversely calculates the temperature value of the first thermistor, that is, determines the temperature value of the current environment.

[0063] Subsequently, the control unit compares the temperature value with a preset temperature compensation range. If the current temperature value is within the first temperature compensation range preset by the first temperature compensation network, the first switching element is kept on to continue using the first temperature compensation network for temperature compensation. If the current temperature value is not within the first temperature compensation range preset by the first temperature compensation network, but within the second temperature compensation range preset by the second temperature compensation network, the on / off states of the first and second switching elements are switched, i.e., the first switching element is turned off and the second switching element is turned on to enable the second temperature compensation network for compensation.

[0064] It should be noted that after the control unit calculates the real-time resistance of the thermistor based on the voltage divider value, it deduces the current temperature value based on the inherent temperature resistance characteristic of the thermistor. This temperature resistance characteristic is determined by the specific material properties of the thermistor, and its specific calculation method is common knowledge in this field, so it will not be elaborated on here.

[0065] As an optional implementation method, please refer to Figure 2This is a schematic diagram of the structure of the first thermistor branch in the temperature compensation circuit for adaptive wide-temperature scenarios provided in this application embodiment. The first thermistor branch provided in this application also includes a first compensation resistor and a first adjustable resistor. In this application, the first thermistor and the first matching resistor are connected together and then connected to the first compensation resistor. The first adjustable resistor is connected in parallel across the first thermistor and the first compensation resistor.

[0066] Thus, by cooperating with the first compensation resistor and the first matching resistor, the nonlinear characteristics of the first thermistor can be corrected, making the total resistance range of the first thermistor branch after parallel connection linear and expanding the effective temperature measurement range; furthermore, by setting the first adjustable resistor in parallel across the first thermistor and the first compensation resistor, the circuit parameters can be finely adjusted, making the temperature compensation circuit adaptable to circuit components of different specifications.

[0067] In an optional embodiment, please refer to Figure 3 This is a schematic diagram of the structure of the second thermistor branch in the temperature compensation circuit for adaptive wide-temperature scenarios provided in this application embodiment. The second thermistor branch provided in this application is also provided with a second compensation resistor and a second adjustable resistor. In this application, the second thermistor and the second matching resistor are connected together and then connected to the second compensation resistor. The second adjustable resistor is connected in parallel across the second thermistor and the second compensation resistor.

[0068] Similarly, by using the second compensation resistor and the second matching resistor together, the nonlinear characteristics of the second thermistor can be corrected, making the total resistance range of the second thermistor branch after parallel connection linear, thus expanding the effective temperature measurement range.

[0069] Furthermore, by connecting the second adjustable resistor in parallel across the second thermistor and the second compensation resistor, the circuit parameters can be finely adjusted, making the temperature compensation circuit adaptable to circuit components of different specifications.

[0070] In one specific embodiment, please refer to Figure 4 This is a circuit diagram of the temperature compensation circuit for adaptive wide-temperature scenarios provided in the embodiments of this application. The first switching element provided in this application is a first MOS transistor. A first connection resistor is provided between the drain of the first MOS transistor and the first thermistor branch. The source of the first MOS transistor is grounded. The gate of the first MOS transistor is connected to the first gate resistor and then connected to the control pin of the control unit.

[0071] Similarly, the second switching element provided in this application is the second MOS transistor in the figure. This application provides a second connection resistor between the drain of the second MOS transistor and the second thermistor branch, grounds the source of the second MOS transistor, and connects the gate of the second MOS transistor to the control pin of the control unit after connecting the gate resistor.

[0072] For example, the first and second switching elements described above can also be configured as relays, transistors, and analog control switches.

[0073] It should be noted that the equivalent resistance of a MOSFET is usually extremely low and negligible when it is turned on, which can avoid additional voltage division that would affect the accuracy of the thermistor branch. Moreover, the on and off time of a MOSFET is only ten nanoseconds, which is much faster than the response of a relay. The MOSFET can be turned on and off simply by applying a suitable voltage to the gate, without the need for precise control of the base current like a transistor. Therefore, this application preferably sets the first and second switching elements in the form of MOSFETs.

[0074] In this embodiment, the first connection resistor and the second connection resistor are provided to prevent excessive surge current from damaging the corresponding temperature compensation network at the moment the first MOSFET or the second MOSFET is turned on. In addition, there is usually a parasitic capacitance between the gate and source of the MOSFET, which may cause oscillation during high-speed switching. By setting the first gate resistor and the second gate resistor, the oscillation can be effectively damped, the gate drive current can be limited, and the control unit output can be prevented from being overloaded.

[0075] Thus, taking the first temperature compensation network as an example, the control unit outputs a high level, which is applied to the gate of the first MOSFET through the first gate resistor, controlling the first MOSFET to conduct, thereby enabling the first temperature compensation network; when it is necessary to turn off the first temperature compensation network and enable the second temperature compensation network, the control unit outputs a low level, controlling the first MOSFET to turn off, thereby turning off the first temperature compensation network.

[0076] As an optional implementation, this application connects one end of the first voltage divider resistor and the second voltage divider resistor to the power supply voltage, connects the ADC sampling pin of the control unit between the first voltage divider resistor and the first thermistor branch, and connects the sampling pin of the control unit between the second voltage divider resistor and the second thermistor branch.

[0077] It is understood that this application uses a first voltage divider resistor and a first thermistor branch to form a series voltage divider, and a second voltage divider resistor and a second thermistor branch to form a series voltage divider. When the resistance of the thermistor in the thermistor branch changes with temperature, the voltage division value at the sampling point changes. The resistance of the thermistor and the current actual temperature are then deduced from the voltage division value, so that the control unit can activate the appropriate temperature compensation network for temperature compensation based on the actual temperature.

[0078] In one specific embodiment provided in this application, please continue to refer to... Figure 4The first temperature compensation network corresponds to temperature compensation network A in the figure. Temperature compensation network A is provided with a first voltage divider resistor R10, a first thermistor R11, a first matching resistor R12, a first compensation resistor R13, a first adjustable resistor R14, a first connection resistor R15, a first switching element, a first MOS transistor, and a first gate resistor R16.

[0079] Furthermore, the second temperature compensation network corresponds to temperature compensation network B in the figure. Temperature compensation network B is provided with a second voltage divider resistor R20, a second thermistor R21, a second matching resistor R22, a second compensation resistor R23, a second adjustable resistor R24, a second connection resistor R25, a second switching element, a second MOS transistor, and a second gate resistor R26.

[0080] For details regarding the specific connection relationships of the components in temperature-compensated network A and temperature-compensated network B, please refer to the descriptions in the first and second temperature-compensated networks above. This application will not elaborate further on these details here.

[0081] In an optional embodiment, the control unit can be configured as a common controller such as an MCU (Microcontroller Unit), a PLC (Programmable Logic Controller), or a PFGA (Field-Programmable Gate Array). Any configuration that can achieve the functions of the control unit described above is feasible, and this application does not impose any specific restrictions on it.

[0082] For preferred options, please refer to [the provided text]. Figure 5 This is a circuit diagram of the control unit in the temperature compensation circuit for adaptive wide-temperature scenarios provided in this application embodiment. This application selects a MUC as the controller to switch between the first temperature compensation network and the second temperature compensation network. The controller should have an ADC sampling pin, a TEMPA control pin connected to the first switching element to control the enabled state of the first temperature compensation network, and a TEMPB control pin connected to the second switching element to control the enabled state of the second temperature compensation network.

[0083] In this embodiment, the controller should compare the currently determined temperature value with a preset first temperature compensation range and a second temperature compensation range. When the temperature value is within the first temperature compensation range, the first switching element is turned on and the second switching element is turned off, and the first temperature compensation network is enabled to perform temperature compensation on the sensor output. When the temperature value is within the second temperature compensation range, the second switching element is turned on and the first switching element is turned off, and the second temperature compensation network is enabled to perform temperature compensation on the sensor output.

[0084] Thus, this application directly switches between the first and second temperature compensation networks via the MCU, eliminating the need for a level conversion chip. This reduces costs while increasing integration. Furthermore, by directly driving the first and second switching elements through the MCU's control pins, the switching delay can be effectively reduced. Therefore, this method has certain advantages over hardware switching methods using comparators, inverters, etc.

[0085] Furthermore, since the resistance of the first thermistor is less than that of the second thermistor, the upper limit of the first temperature compensation interval should not exceed the lower limit of the second temperature compensation interval, thus ensuring that there is no overlap between the first and second temperature compensation intervals.

[0086] Based on this, this application sets the resistance value of the first voltage divider resistor to be less than the resistance value of the second voltage divider resistor, and sets the resistance value of the first matching resistor to be less than the resistance value of the second matching resistor. Through the differentiated settings between the first voltage divider resistor, the first matching resistor, the second voltage divider resistor, and the second matching resistor, it ensures that the first temperature compensation network and the second temperature compensation network are adapted to their respective temperature compensation ranges.

[0087] In one specific embodiment provided in this application, both the first MOS transistor and the second MOS transistor can be configured as N-channel MOS transistors.

[0088] Furthermore, the resistance of the first thermistor R11 is set to 10kΩ, and the resistance of the first gate resistor R16 is set to 10kΩ, so that the first temperature compensation range corresponding to the first temperature compensation network is (-40℃~10℃); the resistance of the second thermistor R21 is set to 22kΩ, and the resistance of the second gate resistor R26 is also set to 10kΩ, so that the second temperature compensation range corresponding to the second temperature compensation network is [10℃~100℃].

[0089] It should be noted that the above-mentioned correspondence between the first thermistor and the second thermistor and the corresponding first and second temperature compensation ranges is only an optional embodiment provided by this application. In actual application, those skilled in the art can adjust the performance parameters of thermistors, voltage divider resistors, matching resistors and other components in the temperature compensation network according to the specific application scenario requirements, so as to flexibly adapt them to the temperature compensation range to be achieved.

[0090] Of course, a third or fourth temperature compensation network can be added to divide the temperature compensation range more precisely. All of the above adjustment methods are feasible, and this application does not impose any further limitations on them.

[0091] As an optional implementation, if the first and second switching elements are simultaneously turned on at the moment of switching when the control unit switches between the first and second temperature compensation networks, it may trigger a momentary short-circuit current of tens of amperes. This may not only cause the MOSFET to burn out due to thermal breakdown caused by overheating, but may also trigger the sensor to output falsely, and in severe cases, damage the entire circuit. Therefore, in the temperature compensation circuit, it is also necessary to set a reasonable dead time to reduce the impact of transient interference on adjacent circuits and ensure the stable output of the sensor.

[0092] Taking an N-channel MOSFET as an example, the maximum turn-off delay time of the MOSFET is toff_max = 20ns, the minimum turn-on delay time is ton_min = 8ns, and the safety margin time is tmargin = 5ns. At this time, the minimum dead time tdead_min is determined to be toff_max - ton_min + tmargin = 20 - 8 + 5 = 17ns. Therefore, the dead time range of 20-50ns can be limited to cover as many additional variables as possible and ensure that there is no risk of overlapping conduction under complex extreme operating conditions.

[0093] Optionally, an RC network (not shown in the figure) consisting of resistors and capacitors can be inserted into the gate drive path of the MOS transistor to delay the drive signal through the charging and discharging characteristics of the capacitor, thereby achieving dead-time isolation. However, this delay method is greatly affected by temperature and voltage fluctuations. Therefore, this application prefers to control the dead time through an MCU.

[0094] Furthermore, once the dead time is determined, it can be observed and tested using an oscilloscope to measure whether there is overlap between the rising and falling edges of the gate drive signals of the first and second MOSFETs. Through multiple experiments, it can be ensured that the measured dead time is always within the preset dead time range under extreme temperature and voltage fluctuations.

[0095] As an optional implementation, the temperature compensation circuit provided in this application needs to be further tested for switching, specifically including low temperature switching test and high temperature switching test. During the low temperature switching test, the sensor equipped with the temperature compensation circuit provided in this application is placed in a temperature chamber and heated from -40°C to 10°C at a rate of 1°C / min. It is ensured that when the actual temperature is ≥10°C+2°C (12°C), the control unit controls the second switching element to turn on, the second temperature compensation network is started, and the sensor output signal drift is <±0.1%.

[0096] Furthermore, during the high-temperature switching test, the temperature was reduced from 100℃ to 10℃ at a rate of 2℃ / min. When the actual temperature was ≤10℃-2℃ (8℃), the control unit controlled the first switching element to turn on, the first temperature compensation network was started, the sensor output signal drift was <±0.1%, and the switching time was <100μs.

[0097] Optionally, boundary jitter testing can also be performed on the sensor, that is, in The test was repeated to verify whether the sensor could reliably switch.

[0098] In an optional embodiment, the drain voltage of the first MOSFET and the second MOSFET can also be detected by the MCU. If the drain voltage is higher than a preset threshold (e.g., 0.2V) when the MOSFET is turned on, it can be considered that the current circuit is overloaded or faulty. Therefore, it is necessary to determine that it is abnormal and trigger the corresponding protection mechanism.

[0099] Preferably, a reset unit can also be set up so that when the switching logic of the controller is stuck, a forced reset can be performed through the reset unit.

[0100] It is understood that the above-mentioned overload protection and fault alarm triggering protection mechanisms based on voltage detection, as well as the forced reset in case of system abnormality through the reset unit, are common technical means in circuit design. Therefore, this application will not go into too much detail about the specific implementation details of the above protection mechanisms and reset methods.

[0101] Furthermore, when packaging the first temperature compensation network and the second temperature compensation network, it is preferable to package them independently to support plug-and-play replacement, reduce maintenance downtime, and also to lay a heat dissipation via array under the first and second switching elements to improve heat dissipation efficiency.

[0102] For example, a 2oz copper foil can be used to arrange a heat dissipation via array with a 0.3mm aperture and a 1mm spacing.

[0103] The temperature compensation circuit provided in this application sets up a first temperature compensation network and a second temperature compensation network covering different temperature compensation ranges. The control unit collects the voltage signal of the currently activated first or second temperature compensation network, determines the resistance value of the currently activated first or second thermistor and the current temperature value based on the voltage signal, compares the current temperature value with a preset temperature compensation range, and switches the conduction state of the first and second switching elements according to the comparison result, so as to activate the temperature compensation network corresponding to the currently conducting switching element for temperature compensation. This application flexibly switches the appropriate temperature compensation network according to the current real-time temperature value for accurate temperature compensation, avoiding the parameter drift phenomenon that occurs in traditional single thermistors over a wide temperature range, and ensuring that the sensor can still output stably under a large temperature span.

[0104] Based on the aforementioned temperature compensation circuit for adaptive wide-temperature scenarios, this application also provides a temperature compensation method for adaptive wide-temperature scenarios, please refer to... Figure 6 Here is a flowchart of an adaptive wide-temperature scenario temperature compensation method provided in this application embodiment. The method includes the following steps:

[0105] S1: Collect the voltage division value of the thermistor circuit in the currently enabled temperature compensation network;

[0106] S2: Determine the temperature value of the thermistor in the current temperature compensation network based on the voltage divider value;

[0107] S3: Compare the temperature value with the preset first temperature compensation interval and second temperature compensation interval;

[0108] S4: Based on the comparison result, switch the conduction state of the first switching element and the second switching element to enable the temperature compensation network adapted to the current temperature value to perform temperature compensation on the sensor output.

[0109] As an optional implementation method, please refer to Figure 7 This is a flowchart illustrating the switching of the conduction state of a switching element in the temperature compensation method for adaptive wide-temperature scenarios provided in this application embodiment. The above-mentioned switching of the conduction states of the first and second switching elements based on the comparison result to enable a temperature compensation network adapted to the current temperature value to perform temperature compensation on the sensor output includes:

[0110] S40: Determine whether the temperature value is within the preset first temperature compensation range or the second temperature compensation range;

[0111] S41: When the temperature value is within the first temperature compensation range, the first switching element is turned on and the second switching element is turned off, and the first temperature compensation network is enabled to perform temperature compensation on the sensor output.

[0112] S42: When the temperature value is within the second temperature compensation range, the second switching element is turned on and the first switching element is turned off, and the second temperature compensation network is enabled to perform temperature compensation on the sensor output.

[0113] For other details regarding the implementation of the above technical solution in each step of the temperature compensation method, please refer to the description in the temperature compensation circuit for adaptive wide-temperature scenarios provided in the above application embodiments, which will not be repeated here.

[0114] In the several embodiments provided in this application, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between devices or units, and may be electrical, mechanical, or other forms.

[0115] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0116] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A temperature compensation circuit for adaptive wide-temperature scenarios, characterized in that, include: The first temperature compensation network includes a first voltage divider resistor, a first thermistor branch, and a first switching element for controlling the activation state of the first temperature compensation network, wherein the first thermistor branch includes a first thermistor and a first matching resistor connected in parallel. The second temperature compensation network includes a second voltage divider resistor, a second thermistor branch, and a second switching element for controlling the activation state of the second temperature compensation network, wherein the second thermistor branch includes a second thermistor and a second matching resistor connected in parallel, and the first thermistor is less than the resistance value of the second thermistor. The control unit, connected to the first temperature compensation network and the second temperature compensation network, is used to collect the voltage division value of the thermistor branch in the currently enabled temperature compensation network, and determine the temperature value of the thermistor in the current temperature compensation network based on the voltage division value. The control unit is also used to compare the temperature value with a preset temperature compensation range, and switch the conduction state of the first switching element and the second switching element according to the comparison result, so as to enable the temperature compensation network adapted to the current temperature value to perform temperature compensation on the sensor output.

2. The temperature compensation circuit for adaptive wide-temperature scenarios as described in claim 1, characterized in that, The first thermistor branch also includes a first compensation resistor and a first adjustable resistor. The first thermistor and the first matching resistor are connected together and then connected to the first compensation resistor. The first adjustable resistor is connected in parallel across the first thermistor and the first compensation resistor. And / or, the second thermistor branch further includes a second compensation resistor and a second adjustable resistor, the second thermistor and the second matching resistor are connected together and then connected to the second compensation resistor, and the second adjustable resistor is connected in parallel across the second thermistor and the second compensation resistor.

3. The temperature compensation circuit for adaptive wide-temperature scenarios as described in claim 1, characterized in that, The first switching element is a first MOSFET. A first connection resistor is provided between the drain of the first MOSFET and the first thermistor branch. The source of the first MOSFET is grounded. The gate of the first MOSFET is connected to the control unit after being connected to the first gate resistor. And / or, the second switching element is a second MOSFET, a second connection resistor is provided between the drain of the second MOSFET and the second thermistor branch, the source of the second MOSFET is grounded, and the gate of the second MOSFET is connected to the control unit after being connected to the second gate resistor.

4. The temperature compensation circuit for adaptive wide-temperature scenarios as described in claim 1, characterized in that, One end of the first voltage divider resistor and the second voltage divider resistor are connected to the power supply voltage. The sampling pin of the control unit is connected between the first voltage divider resistor and the first thermistor branch, and between the second voltage divider resistor and the second thermistor branch.

5. The temperature compensation circuit for adaptive wide-temperature scenarios as described in claim 1, characterized in that, The control unit is used to compare the temperature value with a preset first temperature compensation range and a preset second temperature compensation range, and determine whether the temperature value is within the preset first temperature compensation range or the preset second temperature compensation range. When the temperature value is within the first temperature compensation range, the first switching element is turned on and the second switching element is turned off, and the first temperature compensation network is enabled to perform temperature compensation on the sensor output. When the temperature value is within the second temperature compensation range, the second switching element is turned on and the first switching element is turned off, enabling the second temperature compensation network to perform temperature compensation on the sensor output.

6. The temperature compensation circuit for adaptive wide-temperature scenarios as described in claim 5, characterized in that, The upper limit of the first temperature compensation interval does not exceed the lower limit of the second temperature compensation interval.

7. The temperature compensation circuit for adaptive wide-temperature scenarios as described in claim 6, characterized in that, The resistance of the first thermistor is 10kΩ, and the first temperature compensation range is (-40℃~10℃). The resistance of the second thermistor is 22kΩ, and the second temperature compensation range is [10℃~100℃].

8. The temperature compensation circuit for adaptive wide-temperature scenarios as described in claim 1, characterized in that, The resistance of the first voltage divider resistor is less than the resistance of the second voltage divider resistor, and the resistance of the first matching resistor is less than the resistance of the second matching resistor.

9. A temperature compensation method for adaptive wide-temperature scenarios, implemented based on the temperature compensation circuit for adaptive wide-temperature scenarios as described in any one of claims 1-8, characterized in that, The temperature compensation method includes the following steps: Collect the voltage drop value of the thermistor circuit in the currently enabled temperature compensation network; The temperature value of the thermistor in the current temperature compensation network is determined based on the voltage divider value. The temperature value is compared with a preset first temperature compensation range and a second temperature compensation range; Based on the comparison results, the conduction states of the first and second switching elements are switched to enable a temperature compensation network adapted to the current temperature value to perform temperature compensation on the sensor output.

10. The temperature compensation method for adaptive wide-temperature scenarios as described in claim 9, characterized in that, The step of switching the conduction states of the first and second switching elements according to the comparison result to enable a temperature compensation network adapted to the current temperature value to perform temperature compensation on the sensor output includes: Determine whether the temperature value is within the preset first temperature compensation range or the second temperature compensation range; When the temperature value is within the first temperature compensation range, the first switching element is turned on and the second switching element is turned off, and the first temperature compensation network is enabled to perform temperature compensation on the sensor output. When the temperature value is within the second temperature compensation range, the second switching element is turned on and the first switching element is turned off, enabling the second temperature compensation network to perform temperature compensation on the sensor output.

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