Temperature detection circuit with functional safety

Abstract

The invention provides a temperature detection circuit with functional safety, and relates to the technical field of temperature detection. The circuit comprises a self-checking module, a temperature detection module and a control module which are connected with one another, and a power supply module which is respectively connected with the self-checking module and the temperature detection module. The power supply module comprises a power supply and a divider resistor which are connected in sequence, and is used for providing voltage for the self-checking module or the temperature detection module through the divider resistor; the self-checking module is used for being conducted after responding to the self-checking signal and performing voltage division with the power supply module to generate a first voltage signal; the temperature detection module is used for being switched on after responding to the temperature detection signal and performing voltage division with the power supply module to generate a second voltage signal; and the control module is used for outputting a self-checking signal or a temperature detection signal and receiving the first voltage signal or the second voltage signal so as to carry out circuit function safety judgment or temperature calculation. The reliability of the circuit is ensured, and the detection result is more accurate.

Description

Technical Field

[0001] This application relates to the technical field of temperature detection, and particularly to a temperature detection circuit with functional safety. Background Art

[0002] Temperature detection circuits are widely used in fields such as new energy vehicles, industrial control, and consumer electronics. Especially in the in-vehicle environment of new energy vehicles, their reliability and functional safety directly affect the safe operation of the entire vehicle system. With the popularization of functional safety standards, higher requirements are put forward for the diagnostic capabilities of circuits to ensure that they can be detected in a timely manner and safety measures can be taken under abnormal conditions.

[0003] However, existing temperature detection schemes usually use a differential amplifier circuit to sample the voltage-dividing signal of a thermistor. After converting it into a digital signal through an ADC (Analog to Digital Converter), the ambient temperature is calculated by combining the voltage-dividing ratio and the temperature-resistance correspondence table. Although this scheme has a simple structure and low cost, when the circuit itself fails, it will lead to misjudgment of temperature information, thus causing potential safety hazards. Therefore, the existing schemes have the problem that the circuit reliability is poor, which in turn leads to inaccurate detected temperature information. Summary of the Invention

[0004] A temperature detection circuit with functional safety provided by an embodiment of this application is used to solve the problem that the existing schemes have poor circuit reliability, which in turn leads to inaccurate detected temperature information.

[0005] In a first aspect, an embodiment of this application provides a temperature detection circuit with functional safety. The temperature detection circuit includes a self-checking module, a temperature detection module, and a control module that are connected to each other, and a power supply module. The power supply module is respectively connected to the self-checking module and the temperature detection module;

[0006] The power supply module includes a power supply and a voltage-dividing resistor connected in sequence, and is used to provide voltage to the self-checking module or the temperature detection module through the voltage-dividing resistor;

[0007] The control module is used to output a self-checking signal or a temperature detection signal;

[0008] The self-checking module is used to conduct after responding to the self-checking signal output by the control module, and perform voltage division with the power supply module to generate a first voltage signal;

[0009] The temperature detection module is used to conduct after responding to the temperature detection signal output by the control module, and perform voltage division with the power supply module to generate a second voltage signal;

[0010] The control module is also used to receive the first voltage signal or the second voltage signal to perform circuit functional safety judgment or temperature calculation.

[0011] In a possible implementation, the self-check module includes a switch unit and a first resistor unit;

[0012] The switch unit is used to receive the self-check signal output by the control module and conduct the first resistor unit in response to the self-check signal;

[0013] The first resistor unit is used to form a voltage-dividing circuit with the voltage-dividing resistor of the power supply module in the conducting state to generate a first voltage signal.

[0014] In a possible implementation, the switch unit includes a high-side switch unit and / or a low-side switch unit; the high-side switch unit is connected between the voltage-dividing resistor and the first resistor unit and is used to receive the first self-check signal output by the control module and conduct the path between the voltage-dividing resistor and the first resistor unit in response to the first self-check signal; and / or, the low-side switch unit is connected between the first resistor unit and the ground and is used to receive the second self-check signal output by the control module and conduct the path between the first resistor unit and the ground in response to the second self-check signal; wherein, the self-check signal includes the first self-check signal and / or the second self-check signal.

[0015] In a possible implementation, when the switch unit includes a high-side switch unit and a low-side switch unit, the high-side switch unit includes a first switching device and a second switching device, the low-side switch unit includes a third switching device, and the first resistor unit includes a first resistor; wherein, the first end of the first switching device is connected to the control module, the second end of the first switching device is connected to the first end of the second switching device, and the third end of the first switching device is grounded; the second end of the second switching device is connected to one end of the voltage-dividing resistor, and the third end of the second switching device is connected to one end of the first resistor; the other end of the first resistor is connected to the second end of the third switching device; the first end of the third switching device is connected to the control module, and the third end of the third switching device is grounded.

[0016] In a possible implementation, the switching device in the switch unit is a MOS transistor and / or a triode.

[0017] In a possible implementation, the control module is further used to:

[0018] After receiving the first voltage signal, compare the first voltage signal with a preset voltage value, and the preset voltage value is determined according to the resistance values of the voltage-dividing resistor and the first resistor unit in the self-check module;

[0019] If the first voltage signal is different from the preset voltage value, output a circuit fault signal.

[0020] In a possible implementation, the temperature detection module includes a fourth switching device and a thermistor. The fourth switching device is connected to the control module, the thermistor, and the ground respectively. The thermistor is connected to a voltage dividing resistor; or, the fourth switching device is connected to the control module, the voltage dividing resistor, and the thermistor respectively, and the thermistor is connected to the ground; wherein, the fourth switching device is configured to receive a temperature detection signal output by the control module, and conduct a path from the thermistor to the ground or from the thermistor to the voltage dividing resistor in response to the temperature detection signal; the thermistor is configured to form a voltage dividing circuit with the voltage dividing resistor of the power supply module in the conducting case to generate a second voltage signal.

[0021] In a possible implementation, the temperature detection circuit further includes a signal amplification module. The input end of the signal amplification module is connected to the output ends of the power supply module, the self-check module, and the temperature detection module respectively. The output end of the signal amplification module is connected to the control module; the signal amplification module is configured to amplify the first voltage signal or the second voltage signal to obtain an amplified voltage signal, and output it to the control module; correspondingly, the control module is configured to output a self-check signal or a temperature detection signal, and receive the amplified voltage signal to perform circuit functional safety judgment or temperature calculation.

[0022] In a possible implementation, the signal amplification module includes a differential amplifier and a second resistor unit;

[0023] The differential amplifier is configured to perform differential amplification processing on the first voltage signal or the second voltage signal to obtain an amplified voltage signal, and output it to the control module;

[0024] The second resistor unit is configured to set the gain and input impedance of the signal amplification module, and determine the amplification multiple of the differential amplifier.

[0025] In a possible implementation, the differential amplifier is an operational amplifier, and the second resistor unit includes a second resistor, a third resistor, a fourth resistor, and a fifth resistor; wherein, the non-inverting input end of the operational amplifier is connected to the output ends of the power supply module, the self-check module, and the temperature detection module respectively through the third resistor; one end of the second resistor is connected to the non-inverting input end of the operational amplifier, and the other end of the second resistor is grounded; the inverting input end of the operational amplifier is connected to the output end of the operational amplifier through the fourth resistor, and the output end of the operational amplifier is connected to the control module; one end of the fifth resistor is connected to the inverting input end of the operational amplifier, and the other end of the fifth resistor is grounded.

[0026] In a second aspect, an embodiment of the present application provides a server, including the temperature detection circuit with functional safety in the first aspect and / or various possible implementations of the first aspect above.

[0027] A temperature detection circuit with functional safety provided by an embodiment of the present application. The circuit includes a self-check module, a temperature detection module, a control module, and a power supply module that are connected to each other. The power supply module is respectively connected to the self-check module and the temperature detection module. The power supply module includes a power supply and a voltage-dividing resistor connected in sequence, and is used to provide voltage to the self-check module or the temperature detection module through the voltage-dividing resistor. The control module is used to output a self-check signal or a temperature detection signal. The self-check module is used to conduct after responding to the self-check signal output by the control module, and perform voltage division with the power supply module to generate a first voltage signal. The temperature detection module is used to conduct after responding to the temperature detection signal output by the control module, and perform voltage division with the power supply module to generate a second voltage signal. The control module is further used to receive the first voltage signal or the second voltage signal to perform circuit functional safety judgment or temperature calculation. Through the self-check module, the circuit can perform self-check before or during operation to ensure the normal operation of each module, thereby improving the reliability of the circuit. Using the same power supply and voltage-dividing resistor to supply power to the self-check and temperature detection modules reduces the influence of component discreteness on the signal. At the same time, by dynamically switching the working mode through the control module, the fault risk is isolated, ensuring the functional safety of the circuit and the accuracy of the temperature detection result. Therefore, the embodiment of the present application improves the functional safety and reliability of the circuit through the cooperative voltage division mechanism of the self-check module and the temperature detection module, and ensures the accuracy of the temperature information. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0029] Figure 1 Structural schematic of a temperature detection circuit with functional safety provided by the present application Figure 1 ;

[0030] Figure 2 Structural schematic of a temperature detection circuit with functional safety provided by the present application Figure 2 ;

[0031] Figure 3 Specific structural schematic of a temperature detection circuit with functional safety provided by the present application Figure 1 ;

[0032] Figure 4 Specific structural schematic of a temperature detection circuit with functional safety provided by the present application Figure 2 .

[0033] DESCRIPTION OF REFERENCE NUMERALS:

[0034] Q1: The third switching device; Q2: The fourth switching device; Q3: The second switching device; Q4: The first switching device; R1: Voltage dividing resistor; R2: The second resistor; R3: The third resistor; R4: Thermistor; R5: The fourth resistor; R6: The first resistor; R7: The fifth resistor; VCC: Power supply.

[0035] Through the above-mentioned drawings, specific embodiments of the present application have been shown, and there will be a more detailed description hereinafter. These drawings and the written description are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. Detailed Description of the Embodiments

[0036] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0037] It should be understood that the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover but not exclude inclusion. For example, a product or device including a series of components does not necessarily have to be limited to those components clearly listed, but may include other components not clearly listed or inherent to these products or devices.

[0038] The term "module" used in the present application refers to any known or later-developed hardware, software, firmware, artificial intelligence, fuzzy logic, or a combination of hardware or / and software code that can perform functions related to the element.

[0039] In the prior art, the temperature detection scheme usually uses a differential amplifier circuit to sample the voltage dividing signal of the thermistor. After converting it into a digital signal through an ADC, the ambient temperature is calculated by combining the voltage dividing ratio and the temperature-resistance correspondence table. Although this scheme has a simple structure and low cost, the entire circuit lacks a functional safety self-check mechanism and cannot know in real time whether the working state of the temperature detection circuit is normal. When a fault or abnormality occurs in the circuit itself, the system cannot detect and alarm in time, which may lead to misjudgment of the temperature information and further cause potential safety hazards. Especially in the in-vehicle electronic system of new energy vehicles, this lack of functional safety may cause serious safety hazards and even endanger driving safety. Therefore, there is an urgent need for a temperature detection circuit with real-time self-check ability to solve the problem that the existing scheme has poor circuit reliability, resulting in inaccurate detected temperature information.

[0040] To solve the above problems, an embodiment of the present application provides a temperature detection circuit with functional safety. Through a self-check module, the circuit can perform self-check before or during operation. When the self-check module is turned on, it forms a fixed voltage division circuit with a voltage dividing resistor and generates a first voltage signal. The control module can identify circuit faults by analyzing the first voltage signal to ensure the normal operation of each module, thereby improving the reliability of the circuit. When the temperature detection module is turned on, the voltage dividing resistor and the thermistor in the module form a variable voltage division circuit to generate a second voltage signal. The control module generates temperature information by analyzing the second voltage signal, which can ensure the accuracy of the temperature information. In addition, the same power supply and voltage dividing resistor are used to provide a stable voltage for the self-check module and the temperature detection module. By switching the signals (self-check signal / temperature detection signal) of the control module to select the voltage division path, hardware resource reuse can be achieved, redundant components can be reduced, and the circuit complexity and cost can be lowered.

[0041] The following uses specific embodiments to elaborate in detail on the technical solution of the present application and how the technical solution of the present application solves the above technical problems. These several specific embodiments can be combined with each other. For the same or similar concepts or processes, they may not be repeated in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0042] Figure 1 Structural schematic of a temperature detection circuit with functional safety provided by the present application Figure 1 It can be applied to fields such as new energy vehicles, automotive electronics, industrial control, or consumer electronics. As Figure 1 shown, the temperature detection circuit includes: a self-check module, a temperature detection module, and a control module that are connected to each other, and a power supply module. The power supply module is respectively connected to the self-check module and the temperature detection module; the power supply module includes a power supply and a voltage dividing resistor connected in sequence, and is used to provide voltage to the self-check module or the temperature detection module through the voltage dividing resistor; the control module is used to output a self-check signal or a temperature detection signal; the self-check module is used to conduct after responding to the self-check signal output by the control module and perform voltage division with the power supply module to generate a first voltage signal; the temperature detection module is used to conduct after responding to the temperature detection signal output by the control module and perform voltage division with the power supply module to generate a second voltage signal; the control module is further used to receive the first voltage signal or the second voltage signal to perform circuit functional safety judgment or temperature calculation.

[0043] In this embodiment, the self-check module is used to perform functional self-check at the startup of the circuit or at a specific moment to ensure that all components of the circuit are working properly. This module may include a series of switching devices and resistors, which can be turned on under the instruction of the control module and form a voltage-dividing circuit with the voltage-dividing resistors in the power supply module to generate a fixed voltage signal, i.e., the first voltage signal, at the voltage-dividing point (i.e., the detection point connected to the control module). This signal is analyzed by the control module, such as comparing its consistency with a preset value, to make a judgment on the functional safety of the circuit, such as determining whether the circuit is in a normal state.

[0044] The temperature detection module can be a circuit for real-time monitoring of the ambient temperature or the temperature inside the device. It usually includes a thermistor, whose resistance value changes with temperature. Among them, the thermistor can select a suitable thermistor material according to application requirements. Exemplarily, a negative temperature coefficient thermistor or a positive temperature coefficient thermistor in the new material industry can be used, which has the advantages of fast response speed, high sensitivity, low cost, etc. in temperature detection, further improving the temperature detection efficiency. Under the instruction of the control module, the temperature detection module is turned on and forms a voltage-dividing circuit with the voltage-dividing resistors in the power supply module to generate a temperature-related voltage signal, i.e., the second voltage signal, at the voltage-dividing point. This signal can be used to calculate the current temperature after being processed.

[0045] The control module is used to coordinate and control the operation of the self-check module and the temperature detection module, process signals and make decisions. Further, the control module outputs self-check signals or temperature detection signals, receives the voltage signals output by the temperature detection module or the self-check module, makes a judgment on the functional safety of the circuit or calculates the temperature according to the received signals, and outputs corresponding control signals (such as fault control signals) or the currently detected temperature value. The control module can be composed of an MCU control chip, which is used for the acquisition of voltage signals and the output of control signals such as self-check signals and temperature detection signals.

[0046] The power supply module includes a power supply and voltage-dividing resistors, which can provide working voltage for the self-check module and the temperature detection module and participate in voltage-dividing calculations.

[0047] The self-check signal and the temperature detection signal can refer to the logic level signals output by the control module. Among them, the self-check signal is used to trigger the circuit to enter the functional safety self-check mode to verify the normal working state of the temperature detection circuit; the temperature detection signal is used to switch the circuit to the normal working mode to realize the temperature measurement function. In addition, the trigger conditions or rules for the self-check mode and the normal working mode can be preset in the control module. For example, the self-check mode is automatically triggered at system startup to ensure that the circuit is in a normal state before the system starts normal operation; or the user can manually trigger the self-check mode through a specific operation (such as a specific combination of keys), which can be used to detect whether there are potential problems in the circuit during system operation; the self-check mode can also be triggered by a specific event (such as the system detecting abnormal signals or power fluctuations, etc.) or a specific moment (setting a timer) to ensure the long-term stability and reliability of the system circuit. Correspondingly, the normal working mode is usually triggered after the system starts up and completes the self-check; it can also be triggered by a specific operation of the user or an external control signal.

[0048] Among them, there can be multiple level signals, and the on-off of the switch circuit is controlled by the combination of high and low levels. The number is related to the number of switch devices that the circuit needs to control in the functional safety self-check mode or the normal working mode. For example, during the self-check process, the circuit needs to turn on 2 independently controlled switches and turn off 1, then the self-check signal includes 2 high-level signals and 1 low-level signal. If during the temperature detection process, the circuit needs to turn off 2 independently controlled switches and turn on 1, then the temperature detection signal includes 2 low-level signals and 1 high-level signal.

[0049] Since the voltage signals output by the self-check module and the temperature detection module are usually relatively weak, optionally, before the control module receives the first voltage signal or the second voltage signal, the voltage signal can also be amplified to improve the accuracy of the control module in reading the signal. Figure 2 The structural schematic of a temperature detection circuit with functional safety provided by this application Figure 2 , such as Figure 2 As shown, a signal amplification module is added between the control module and the self-check module and the temperature detection module, which is used to amplify the voltage signals output by the self-check module and the temperature detection module, improve the accuracy of the control module in reading the voltage signal, and make the control module process the voltage signal more accurately to achieve precise self-check and temperature detection. In this embodiment, the structure of the signal amplification module is not particularly limited as long as it can realize the voltage signal amplification function.

[0050] A temperature detection circuit with functional safety provided by an embodiment of the present application can perform self-check before or during operation through a self-check module. When the self-check module is turned on, the module and a voltage-dividing resistor form a fixed voltage-dividing circuit and generate a first voltage signal. The control module can identify circuit faults by analyzing the first voltage signal to ensure the normal operation of each module, thereby improving the reliability of the circuit. When the temperature detection module is turned on, the voltage-dividing resistor and the thermistor in the module form a variable voltage-dividing circuit to generate a second voltage signal. The control module generates temperature information by analyzing the second voltage signal, which can ensure the accuracy of the temperature information. In addition, the same power supply and voltage-dividing resistor are used to provide a stable voltage for the self-check module and the temperature detection module. By switching the signals (self-check signal / temperature detection signal) of the control module to select the voltage-dividing path, hardware resource reuse can be achieved, redundant components can be reduced, and the circuit complexity and cost can be lowered.

[0051] Based on the above embodiment, the self-check module includes a switch unit and a first resistor unit. The switch unit is used to receive the self-check signal output by the control module and turn on the first resistor unit in response to the self-check signal. The first resistor unit is used to form a voltage-dividing circuit with the voltage-dividing resistor of the power supply module in the turned-on case and generate a first voltage signal.

[0052] Among them, the switch unit can refer to an electronic switch component controlled by the self-check signal, which can include 1 switch component or multiple switch components, and is used to conduct or cut off the current path of the self-check module according to the state of the signal (such as high level or low level). Exemplarily, the switch unit can include a high-side switch, a low-side switch, or other logic control switches (such as MOSFET, relay).

[0053] The first resistor unit and the voltage-dividing resistor of the power supply module together form a voltage-dividing circuit. In the self-check mode, when the switch unit is turned on, the first resistor unit is in series with the voltage-dividing resistor of the power supply module. It is a fixed resistor participating in voltage division and is used to generate a specific first voltage signal.

[0054] It should be noted that in the normal operation mode, the switch unit is also used to receive the temperature detection signal (such as a low-level signal) output by the control module and turn off the first resistor unit in response to the temperature detection signal to avoid interference or influence of the first resistor unit on the voltage division between the temperature detection module and the power supply module in the normal operation mode.

[0055] The introduction of the switch unit makes the self - test process more flexible and controllable. The voltage - dividing circuit formed by the first resistor unit and the voltage - dividing resistor of the power - supply module can generate a stable and predictable first voltage signal for circuit functional safety judgment. The switch unit can ensure the stable on - off of the self - test path, avoid misoperation, improve the self - test accuracy and reliability of the temperature - detection circuit, help to detect and eliminate circuit faults in a timely manner, and ensure the accuracy and stability of temperature detection.

[0056] Based on the above - mentioned embodiment, the switch unit includes a high - side switch unit and / or a low - side switch unit; the high - side switch unit is connected between the voltage - dividing resistor and the first resistor unit, and is used to receive the first self - test signal output by the control module and conduct the path between the voltage - dividing resistor and the first resistor unit in response to the first self - test signal; and / or, the low - side switch unit is connected between the first resistor unit and the ground, and is used to receive the second self - test signal output by the control module and conduct the path between the first resistor unit and the ground in response to the second self - test signal; wherein, the self - test signal includes the first self - test signal and / or the second self - test signal.

[0057] In this embodiment, the high - side switch unit can refer to one type of the switch unit. For example, a PNP triode is used as the high - side switch and is connected between the voltage - dividing resistor and the first resistor unit. The high - side switch unit is responsible for receiving the first self - test signal output by the control module and conducting the path between the voltage - dividing resistor and the first resistor unit when receiving this signal.

[0058] The low - side switch unit can refer to another type of the switch unit. For example, an NPN triode is used as the low - side switch and is connected between the first resistor unit and the ground. The low - side switch unit is responsible for receiving the second self - test signal output by the control module and conducting the path between the first resistor unit and the ground when receiving this signal.

[0059] The first self - test signal and the second self - test signal are signals output by the control module for controlling the conduction or disconnection of the high - side switch unit and the low - side switch unit. The first self - test signal is usually used to control the high - side switch unit, while the second self - test signal is used to control the low - side switch unit.

[0060] In one example, when the switch unit includes a high - side switch unit, its connection method can be the connection method of the above - mentioned high - side switch unit; when the switch unit includes a low - side switch unit, its connection method can be the connection method of the above - mentioned low - side switch unit; when the switch unit includes a high - side switch unit and a low - side switch unit, its connection method can be the connection method of the above - mentioned high - side switch unit and low - side switch unit.

[0061] It should be noted that in the normal working mode, the high-side switch unit and / or the low-side switch unit are also used to receive the temperature detection signal (such as a low-level signal) output by the control module, and respond to the temperature detection signal to turn off the corresponding connection path, so as to avoid interference or influence on the voltage division of the temperature detection module and the power supply module by the first resistor unit in the normal working mode.

[0062] Figure 3 Specific structural schematic of a temperature detection circuit with functional safety provided by the present application Figure 1 , such as Figure 3 shown, its switch unit includes a low-side switch unit, that is, the third switching device Q1. In the self-check mode, GPIO1 is the second self-check signal, and GPIO1 sends a high-level signal to the third switching device Q1 to make the connection between the first resistor unit (corresponding to the first resistor R6) and the voltage-dividing resistor R1 conductive, so as to generate a first voltage signal. Among them, the first voltage signal is the voltage signal at the voltage-dividing point between the first resistor R6 and the voltage-dividing resistor R1. In the normal working mode, GPIO1 is the temperature detection signal, and GPIO1 sends a low-level signal to the third switching device Q1 to disconnect the connection between the first resistor unit (corresponding to the first resistor R6) and the voltage-dividing resistor R1.

[0063] Through the flexible configuration of the high-side and / or low-side switch units, different circuit layout requirements are adapted, and reliable on-off control of the self-check circuit is realized. Among them, the high-side switch can ensure controllability on the power supply side and avoid abnormal power supply; the low-side switch provides a redundant grounding path to ensure reliable grounding, and double guarantees the circuit safety.

[0064] Based on the above embodiments, when the switch unit includes a high-side switch unit and a low-side switch unit, the high-side switch unit includes a first switching device and a second switching device, the low-side switch unit includes a third switching device, and the first resistor unit includes a first resistor; wherein, the first end of the first switching device is connected to the control module, the second end of the first switching device is connected to the first end of the second switching device, and the third end of the first switching device is grounded; the second end of the second switching device is connected to one end of the voltage-dividing resistor, and the third end of the second switching device is connected to one end of the first resistor; the other end of the first resistor is connected to the second end of the third switching device; the first end of the third switching device is connected to the control module, and the third end of the third switching device is grounded.

[0065] Among them, the switching device in this embodiment can be a transistor (such as a triode, MOSFET, BJT, etc.), or other switches that are turned on or off based on a control signal, such as a relay, which is used to turn on or off the circuit where the first resistor and the voltage-dividing resistor are located according to the control signal. The first resistor is a specific implementation of the first resistor unit, and it forms a voltage-dividing circuit with the voltage-dividing resistor to generate the first voltage signal during self-check.

[0066] In some embodiments, the switching devices in the switching unit are MOS transistors and / or bipolar transistors. Among them, the switching devices in the switching unit can all be MOS transistors, or all be bipolar transistors. When there are multiple switching devices, it can also be a combination of MOS transistors and bipolar transistors. Further, the high-side switch is usually a P-channel MOS transistor and / or an N-channel MOS transistor and / or a PNP bipolar transistor and / or an NPN bipolar transistor, and the low-side switch is usually an N-channel MOS transistor and / or an NPN bipolar transistor. Usually, MOS transistors are more suitable for high-precision and low-power scenarios, while bipolar transistors are more suitable for low-cost and strong anti-interference occasions. Engineers can freely select the device type according to requirements such as cost, power consumption, and speed.

[0067] Figure 4 The specific structural schematic of a temperature detection circuit with functional safety provided by this application Figure 2 , such as Figure 4 shown, in some embodiments, when the switching unit includes a high-side switching unit and a low-side switching unit, the high-side switching unit includes a first switching device Q4 and a second switching device Q3, and the low-side switching unit includes a third switching device Q1. The first resistor unit includes a first resistor R6; wherein, the first end of the first switching device Q4 is connected to the control module, the second end of the first switching device Q4 is connected to the first end of the second switching device Q3, and the third end of the first switching device Q4 is grounded; the second end of the second switching device Q3 is connected to one end of the voltage-dividing resistor R1, and the third end of the second switching device Q3 is connected to one end of the first resistor R6; the other end of the first resistor R6 is connected to the second end of the third switching device Q1; the first end of the third switching device Q1 is connected to the control module, and the third end of the third switching device Q1 is grounded.

[0068] In the self-check mode, GPIO3 is the first self-check signal (high-level signal) to turn on the first switching device Q4 and the second switching device Q3, and GPIO1 is the second self-check signal (high-level signal) to turn on the third switching device Q1; in the normal operating mode, GPIO3 is the temperature detection signal (low-level signal) to turn off the first switching device Q4 and the second switching device Q3, and GPIO1 is the temperature detection signal (low-level signal) to turn off the third switching device Q1.

[0069] Among them, if the first switching device Q4 and the third switching device Q1 are NPN bipolar transistors, the first end is the base, the second end is the collector, and the third end is the emitter. In some examples, an N-channel MOSFET can also be used. If the second switching device Q3 is a PNP bipolar transistor, the first end is the base, the second end is the emitter, and the third end is the collector. In some examples, a P-channel MOSFET can also be used.

[0070] Through the cascaded structure of two-stage devices in the high-side switch unit, the stable conduction of the high-side switch under large current can be ensured; the low-side switch unit consists of a single switching device, which can reduce the power consumption of the control circuit; at the same time, the switch unit is applicable to both bipolar transistor devices and MOSFETs, capable of meeting different voltage / current requirements. This enables the self-checking circuit to more precisely control the on and off states of the circuit, thereby improving the accuracy and reliability of self-checking.

[0071] Based on the above embodiments, the control module is further configured to: after receiving the first voltage signal, compare the first voltage signal with a preset voltage value, where the preset voltage value is determined according to the voltage-dividing resistor and the resistance value of the first resistor unit in the self-checking module; if the first voltage signal is different from the preset voltage value, output a circuit fault signal.

[0072] Among them, the preset voltage value is a standard voltage value preset based on the voltage-dividing circuit theory, as well as the voltage-dividing resistor and the resistance value of the first resistor unit in the self-checking module, and is used to compare with the first voltage signal. In one example, during circuit design, engineers calculate the expected voltage value based on the voltage-dividing resistor and the resistance value of the first resistor unit, and store this value as the preset voltage value in the control module. Further, the control module receives the first voltage signal of the self-checking module through a preset input interface (ADC); and compares it with the stored preset voltage value; if the first voltage signal is the same as or close to the preset voltage value (i.e., within the allowable error range), the control module considers the detection circuit to be working properly and does not perform any special operations; if the first voltage signal is different from the preset voltage value (such as inconsistent values or exceeding the allowable error range), the control module considers that there is a fault in the circuit, and then outputs a circuit fault signal.

[0073] Optionally, the output form of the circuit fault signal can be a logic level signal (such as GPIO outputting a low level), a PWM alarm signal, a bus communication message (such as a CAN bus error frame), etc. This enables the circuit corresponding system to perform fault responses based on this signal, such as triggering a system reset, lighting a fault indicator, recording error logs, etc.

[0074] By comparing the first voltage signal with the preset voltage value and outputting the fault signal, the circuit can automatically detect and identify potential faults, prevent potential failures, and meet the functional safety requirements. Once a fault is detected, the control module can promptly output a fault signal to notify the system or user to perform fault troubleshooting and repair, further improving the reliability and safety of the temperature detection circuit, reducing system downtime or damage caused by circuit faults, and thus reducing maintenance costs and risks.

[0075] Based on the above embodiments, the temperature detection module includes a fourth switching device and a thermistor. The fourth switching device is connected to the control module, the thermistor, and ground respectively. The thermistor is connected to a voltage-dividing resistor; or, the fourth switching device is connected to the control module, the voltage-dividing resistor, and the thermistor respectively, and the thermistor is connected to ground; wherein, the fourth switching device is configured to receive a temperature detection signal output by the control module and conduct a path from the thermistor to ground or from the thermistor to the voltage-dividing resistor in response to the temperature detection signal; the thermistor is configured to form a voltage-dividing circuit with the voltage-dividing resistor of the power supply module in the conducting case to generate a second voltage signal.

[0076] Among them, the fourth switching device can be a transistor (such as a triode, MOSFET, BJT, etc.), or other switches that are turned on or off based on a control signal, such as a relay. It is used to conduct or disconnect the circuit where the thermistor and the voltage-dividing resistor are located according to the control signal.

[0077] In this embodiment, it can be understood that with the rapid development of the new energy vehicle industry, each system of new energy vehicles (such as in-vehicle electronic systems, battery management systems, charging systems, motor control systems, etc.) needs to perform real-time temperature detection to ensure the safety and reliability of the vehicle. The thermistor, as a thermosensitive element with temperature detection function in the new material industry, is suitable for various occasions that require precise temperature measurement and control. Therefore, the embodiments of the present application can adopt a negative temperature coefficient thermistor or a positive temperature coefficient thermistor in the new material industry, so as to provide reliable temperature data support for each system of new energy vehicles (such as in-vehicle electronic systems).

[0078] The second voltage signal is the voltage signal generated after the thermistor and the voltage-dividing resistor form a voltage-dividing circuit, and is output from the voltage-dividing point between the thermistor and the voltage-dividing resistor. This signal reflects the resistance value of the thermistor, and thus reflects the temperature information. Further, when the resistance value of the thermistor changes, the output voltage of the voltage-dividing circuit (i.e., the second voltage signal) will also change accordingly, so that it can be captured by the control module and converted into a temperature value or other processing through a preset internal circuit or algorithm.

[0079] To avoid interference of the thermistor on the first voltage signal output by the self-check module during the self-check process, resulting in a large error between the actual voltage signal and the preset voltage value, in the self-check mode, the fourth switching device is further configured to receive a self-check signal (low-level signal) output by the control module and turn off the path from the thermistor to ground or from the thermistor to the voltage-dividing resistor in response to the self-check signal.

[0080] Continue to refer to Figure 3 and Figure 4, the first terminal of the fourth switching device Q2 (such as the base of an NPN transistor) is connected to the control module, the second terminal of the fourth switching device Q2 (such as the collector of an NPN transistor) is connected to one end of the thermistor R4, the third terminal of the fourth switching device Q2 (such as the emitter of an NPN transistor) is connected to the ground, and the other end of the thermistor R4 is connected to one end of the voltage dividing resistor R1. Among them, the voltage dividing point corresponding to the second voltage signal is between the thermistor R4 and the voltage dividing resistor R1. In the self-check mode, GPIO2 is a self-check signal (low-level signal) to turn off the fourth switching device Q2; in the normal operating mode, GPIO2 is a temperature detection signal (high-level signal) to turn on the fourth switching device Q2.

[0081] By adding a fourth switching device to the temperature detection module, the circuit can flexibly conduct or disconnect the path between the thermistor and the ground or the voltage dividing resistor as needed, avoiding detection errors caused by component interference during self-check and temperature detection, and improving the detection accuracy and reliability of the temperature detection circuit.

[0082] Based on the above embodiments, referring to the above Figure 2 , the temperature detection circuit further includes a signal amplification module. The input end of the signal amplification module is respectively connected to the output ends of the power supply module, the self-check module, and the temperature detection module, and the output end of the signal amplification module is connected to the control module; the signal amplification module is used to amplify the first voltage signal or the second voltage signal to obtain an amplified voltage signal and output it to the control module; correspondingly, the control module is used to output a self-check signal or a temperature detection signal and receive the amplified voltage signal to perform circuit functional safety judgment or temperature calculation.

[0083] It can be understood that the signal amplification module can be a circuit containing an operational amplifier and can be set according to the actual circuit conditions and detection requirements. In the self-check mode, the signal amplification module receives the first voltage signal output by the self-check module, amplifies the first voltage signal, and generates a corresponding amplified voltage signal to output to the control module; after receiving the amplified voltage signal, the control module performs circuit functional safety judgment based on this signal (such as detecting whether the circuit is working properly). In the normal operating mode, the signal amplification module receives the second voltage signal output by the temperature detection module, amplifies the second voltage signal, and generates a corresponding amplified voltage signal to output to the control module; after receiving the amplified voltage signal, the control module performs temperature calculation based on this signal (such as converting the amplified voltage signal into a specific temperature value).

[0084] Through the signal amplification module, the tiny voltage dividing signal is amplified to the optimal detection range of the detection interface (such as ADC) of the control module, improving the circuit's detection ability for weak signals and enhancing the accuracy of circuit functional safety judgment and temperature detection.

[0085] Based on the above embodiments, the signal amplification module includes a differential amplifier and a second resistor unit; the differential amplifier is used to perform differential amplification processing on the first voltage signal or the second voltage signal to obtain an amplified voltage signal and output it to the control module; the second resistor unit is used to set the gain and input impedance of the signal amplification module and determine the amplification factor of the differential amplifier.

[0086] In this embodiment, a differential amplifier is a circuit that can amplify the difference between two input signals. It is often used to amplify weak signals and is composed of various circuit elements, including but not limited to operational amplifiers. In a temperature detection circuit, the differential amplifier is used to perform differential amplification processing on the first voltage signal or the second voltage signal to obtain an amplified voltage signal. For example, the differential amplifier can be an integrated circuit chip, such as LM741, OP07, etc. These amplifiers have characteristics such as high gain, low noise, and high input impedance, and are suitable for precision analog signal processing.

[0087] In addition, the second resistor unit can include multiple feedback resistors and input resistors. By adjusting the resistance values of these resistors, the gain and input impedance of the differential amplification circuit corresponding to the signal amplification module can be set to meet the actual application requirements of different circuits. Among them, the gain determines the proportional relationship between the amplified voltage signal and the original signal, and the input impedance affects the response ability of the circuit to the input signal.

[0088] In addition, usually, the signal amplification module adopts a first-order differential amplification circuit, that is, a single differential amplifier is used as the core amplification element. This differential amplifier may be implemented by a single operational amplifier or by a combination of other circuit elements. However, when the processing ability or gain of the first-order differential amplification circuit does not meet the requirements, a second-order differential amplification circuit can be added behind it to achieve multi-stage amplification of the signal. For example, in scenarios where weak signals need to be amplified or the signal driving ability needs to be improved, each additional first-order differential amplification circuit can further increase the gain and signal quality of the circuit.

[0089] The differential amplifier can enable the circuit to perform precise differential amplification processing on the weak first voltage signal or the second voltage signal, thereby improving the anti-interference ability and transmission efficiency of the signal. At the same time, the second resistor unit enables the circuit to flexibly adjust the gain and input impedance to meet the actual application requirements of different circuits. This not only improves the accuracy and stability of the temperature detection circuit but also enables the circuit to be more widely applied to various occasions that require precise temperature monitoring.

[0090] Based on the above embodiments, the differential amplifier is an operational amplifier, and the second resistor unit includes a second resistor, a third resistor, a fourth resistor, and a fifth resistor; wherein, the non-inverting input terminal of the operational amplifier is connected to the output terminals of the power supply module, the self-check module, and the temperature detection module through the third resistor respectively; one end of the second resistor is connected to the non-inverting input terminal of the operational amplifier, and the other end of the second resistor is grounded; the inverting input terminal of the operational amplifier is connected to the output terminal of the operational amplifier through the fourth resistor, and the output terminal of the operational amplifier is connected to the control module; one end of the fifth resistor is connected to the inverting input terminal of the operational amplifier, and the other end of the fifth resistor is grounded.

[0091] Further, with continued reference to Figure 2 、 Figure 3 and Figure 4 , the second resistor unit includes a second resistor R2, a third resistor R3, a fourth resistor R5, and a fifth resistor R7; wherein, the non-inverting input terminal of the operational amplifier (i.e., the “+” terminal of the op-amp) is connected to one end of R1 in the power supply module, one end of R6 or the second terminal of Q3 in the self-check module, and one end of R4 in the temperature detection module through the third resistor R3 respectively; one end of the second resistor R2 is connected to the non-inverting input terminal of the operational amplifier (i.e., the “+” terminal of the op-amp), and the other end of the second resistor R2 is grounded; the inverting input terminal of the operational amplifier (i.e., the “-” terminal of the op-amp) is connected to the output terminal of the operational amplifier (i.e., the “OUT1” terminal of the op-amp) through the fourth resistor R5, and the output terminal of the operational amplifier (i.e., the “OUT1” terminal of the op-amp) is connected to the control module (corresponding to the ADC interface); one end of the fifth resistor R7 is connected to the inverting input terminal of the operational amplifier (i.e., the “-” terminal of the op-amp), and the other end of the fifth resistor R7 is grounded.

[0092] Optionally, the resistance values of the second resistor R2 and the fourth resistor R5 are equal, the resistance values of the third resistor R3 and the fifth resistor R7 are equal, and the amplification factor of the operational amplifier is the ratio value between the fourth resistor R5 and the fifth resistor R7.

[0093] By defining the structure of the signal amplification module, precise setting of the gain and input impedance is achieved, enabling the circuit to capture and process the signals of the self-check module and the temperature detection module more accurately, thereby more precisely realizing temperature detection and circuit functional safety judgment.

[0094] Next, taking Figure 3 and Figure 4 as examples, the structure and working principle of a temperature detection circuit with functional safety according to an embodiment of the present application are further described. The temperature detection circuit includes: a power supply module, a self-check module, a temperature detection module, a signal amplification module, and a control module, wherein:

[0095] 1. Power supply module: includes a power supply VCC and a voltage-dividing resistor R1.

[0096] 2. The self-check module shown as follows includes: a low-side switch composed of a third switching device Q1 and a first resistor R6. Among them, the third switching device Q1 is connected to the control module and receives the GPIO1 control signal sent by the control module. Figure 3 As shown, the self-check module includes: a high-side switch composed of a first switching device Q4 and a second switching device Q3, a low-side switch composed of a third switching device Q1, and a first resistor R6. Among them, the first switching device Q4 is connected to the control module and receives the GPIO3 control signal sent by the control module, and the third switching device Q1 is connected to the control module and receives the GPIO1 control signal sent by the control module.

[0097] 3. The temperature detection module includes: a thermistor R4 and a fourth switching device Q2. Among them, the fourth switching device Q2 is connected to the control module and receives the GPIO2 control signal sent by the control module. Figure 4 As shown, the self-check module includes: a high-side switch composed of a first switching device Q4 and a second switching device Q3, a low-side switch composed of a third switching device Q1, and a first resistor R6. Among them, the first switching device Q4 is connected to the control module and receives the GPIO3 control signal sent by the control module, and the third switching device Q1 is connected to the control module and receives the GPIO1 control signal sent by the control module.

[0098] 3. The temperature detection module includes: a thermistor R4 and a fourth switching device Q2. Among them, the fourth switching device Q2 is connected to the control module and receives the GPIO2 control signal sent by the control module.

[0099] 4. The signal amplification module includes: an operational amplifier, a second resistor R2, a third resistor R3, a fourth resistor R5, and a fifth resistor R7. According to the principle of differential amplification circuit, the resistance values of the second resistor R2 and the fourth resistor R5 are equal, the resistance values of the third resistor R3 and the fifth resistor R7 are equal, and the amplification factor is equal to the ratio value of the fourth resistor R5 / the fifth resistor R7.

[0100] 5. The control module includes an MCU control chip for collecting analog voltage signals and outputting control signals. The ADC interface of the control module is used to collect the amplified voltage signal (voltage value) output by the signal amplification module. When in the self-check mode, the control signals (self-check signals) output by the control module are: GPIO1 and GPIO3 are high-level signals, and GPIO2 is a low-level signal; when in the normal working mode, the control signals (temperature detection signals) output by the control module are: GPIO1 and GPIO3 are low-level signals, and GPIO2 is a high-level signal.

[0101] As shown Figure 3The working principle of the temperature detection circuit shown is as follows: When the control module outputs a self-check signal, it enters the self-check mode. Among them, GPIO1 is a high-level signal, the low-side switch is turned on, and the voltage-dividing circuit is established as VCC-R1-R6-ground. The self-check module will output a first voltage signal divided by the voltage-dividing resistor R1 and the first resistor R6 (that is, the fixed voltage value corresponding to the voltage-dividing point between the voltage-dividing resistor R1 and the first resistor R6); this signal is input to the signal amplification module, and after differential amplification processing, an amplified voltage signal is obtained and output to the ADC interface of the control module; when the amplified voltage signal detected by the control module is consistent with the preset voltage value, it is determined that the temperature detection circuit is in a normal state, and the self-check of the detection circuit is completed; when the amplified voltage signal is inconsistent with the preset voltage value, a circuit fault signal is output. In addition, GPIO2 is a low-level signal, and the fourth switching device Q2 is turned off to open the thermistor R4 to avoid the influence of the thermistor R4 on the fixed voltage value output by the self-check module.

[0102] When the control module outputs a temperature detection signal, it enters the normal working mode. Among them, GPIO1 is a low-level signal, GPIO2 is a high-level signal, the fourth switching device Q2 is turned on, the low-side switch is turned off, and the voltage-dividing circuit is established as VCC-R1-R4-ground. The temperature detection module will output a second voltage signal divided by the voltage-dividing resistor R1 and the thermistor R4 (that is, the voltage value corresponding to the voltage-dividing point between the voltage-dividing resistor R1 and the thermistor R4); this signal is input to the signal amplification module, and after differential amplification processing, an amplified voltage signal is obtained and output to the ADC interface of the control module; the control module can calculate the current resistance value of the thermistor R4 based on the collected amplified voltage signal, and then know the current temperature according to the temperature-resistance correspondence table of the thermistor R4.

[0103] As Figure 4 The working principle of the temperature detection circuit shown is as follows: When the control module outputs a self-check signal, it enters the self-check mode. Among them, both GPIO1 and GPIO3 are high-level signals, both the high-side switch and the low-side switch are turned on, and the voltage-dividing circuit is established as VCC-R1-R6-ground. The self-check module will output a first voltage signal divided by the voltage-dividing resistor R1 and the first resistor R6 (that is, the fixed voltage value corresponding to the voltage-dividing point between the voltage-dividing resistor R1 and the first resistor R6); this signal is input to the signal amplification module, and after differential amplification processing, an amplified voltage signal is obtained and output to the ADC interface of the control module; when the amplified voltage signal detected by the control module is consistent with the preset voltage value, it is determined that the temperature detection circuit is in a normal state, and the self-check of the detection circuit is completed; when the amplified voltage signal is inconsistent with the preset voltage value, a circuit fault signal is output. In addition, GPIO2 is a low-level signal, and the fourth switching device Q2 is turned off to open the thermistor R4 to avoid the influence of the thermistor R4 on the fixed voltage value output by the self-check module.

[0104] When the control module outputs a temperature detection signal, it enters the normal working mode. Among them, both GPIO1 and GPIO3 are low-level signals, GPIO2 is a high-level signal, the fourth switching device Q2 conducts, the high-side switch and the low-side switch are both turned off, the voltage division circuit is established as VCC - R1 - R4 - ground, and the temperature detection module will output a second voltage signal (that is, the voltage value corresponding to the voltage division point between the voltage division resistor R1 and the thermistor R4) after being divided by the voltage division resistor R1 and the thermistor R4; this signal is input to the signal amplification module, and after differential amplification processing, an amplified voltage signal is obtained and output to the ADC interface of the control module; the control module can calculate the current resistance value of the thermistor R4 according to the collected amplified voltage signal, and then know the current temperature according to the temperature-resistance correspondence table of the thermistor R4.

[0105] The temperature detection circuit with functional safety provided by the embodiments of the present application includes a self-check mode and a normal working mode, which can perform self-check on the reliability of the detection circuit, timely detect abnormalities in the detection circuit, and improve the reliability and intelligence of the circuit. At the same time, the circuit also has the advantages of simple and reliable circuit system, few required peripheral components, and low cost.

[0106] The embodiments of the present application also provide a server, including the temperature detection circuit with functional safety in various possible implementation manners described above. In this embodiment, the specific limitations on the server can refer to the limitations on the temperature detection circuit with functional safety above, and will not be repeated here.

[0107] It should be noted that the structures of various modules or components that the server may involve can be implemented in whole or in part through software, hardware, and their combinations. The structures of various modules or components can be embedded in or independent of the processor in the display device in hardware form, or stored in the memory in the display device in software form, so that the processor can call and execute the corresponding operations of the above server.

[0108] It can be understood that the various digital numbers involved in the embodiments of the present application are only for convenient description and do not limit the scope of the embodiments of the present application. In the embodiments of the present application, the magnitudes of the sequence numbers of the above processes do not mean the order of execution, and the execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0109] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention, which follow the general principles of the present invention and include the common general knowledge or conventional technical means in the technical field not disclosed in the present invention. It is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A temperature detection circuit with functional safety, characterized in that The temperature detection circuit includes a self-check module, a temperature detection module, a control module connected to each other, and a power supply module. The power supply module is respectively connected to the self-check module and the temperature detection module; The power supply module includes a power supply and a voltage-dividing resistor connected in sequence, and is used to provide voltage to the self-check module or the temperature detection module through the voltage-dividing resistor; The control module is used to output a self-check signal or a temperature detection signal; The self-check module is used to conduct after responding to the self-check signal output by the control module, and perform voltage division with the power supply module to generate a first voltage signal; The temperature detection module is used to conduct after responding to the temperature detection signal output by the control module, and perform voltage division with the power supply module to generate a second voltage signal; The control module is further used to receive the first voltage signal or the second voltage signal to perform circuit functional safety judgment or temperature calculation.

2. The temperature detection circuit according to claim 1, wherein The self-check module includes a switch unit and a first resistor unit; The switch unit is used to receive the self-check signal output by the control module and conduct the first resistor unit in response to the self-check signal; The first resistor unit is used to form a voltage-dividing circuit with the voltage-dividing resistor of the power supply module in the conducting state to generate a first voltage signal.

3. The temperature detection circuit according to claim 2, wherein The switch unit includes a high-side switch unit and / or a low-side switch unit; The high-side switch unit is connected between the voltage-dividing resistor and the first resistor unit, and is used to receive the first self-check signal output by the control module and conduct the path between the voltage-dividing resistor and the first resistor unit in response to the first self-check signal; and / or, The low-side switch unit is connected between the first resistor unit and the ground, and is used to receive the second self-check signal output by the control module and conduct the path between the first resistor unit and the ground in response to the second self-check signal; wherein, the self-check signal includes a first self-check signal and / or a second self-check signal.

4. The temperature detection circuit according to claim 3, wherein, When the switch unit includes a high-side switch unit and a low-side switch unit, the high-side switch unit includes a first switching device and a second switching device, the low-side switch unit includes a third switching device, and the first resistor unit includes a first resistor; wherein, The first end of the first switching device is connected to the control module, the second end of the first switching device is connected to the first end of the second switching device, and the third end of the first switching device is grounded; The second end of the second switching device is connected to one end of the voltage-dividing resistor, and the third end of the second switching device is connected to one end of the first resistor; The other end of the first resistor is connected to the second end of the third switching device; The first end of the third switching device is connected to the control module, and the third end of the third switching device is grounded.

5. The temperature detection circuit according to claim 4, wherein The switching device in the switch unit is a MOS transistor and / or a triode.

6. The temperature detection circuit according to any one of claims 1-5, characterized in that, The control module is further used for: After receiving the first voltage signal, comparing the first voltage signal with a preset voltage value, and the preset voltage value is determined according to the resistance values of the voltage-dividing resistor and the first resistor unit in the self-check module; If the first voltage signal is different from the preset voltage value, an output circuit fault signal is output.

7. The temperature detection circuit according to any one of claims 1-5, characterized in that, The temperature detection module includes a fourth switching device and a thermistor. The fourth switching device is respectively connected to the control module, the thermistor and ground. The thermistor is connected to the voltage dividing resistor; or, the fourth switching device is respectively connected to the control module, the voltage dividing resistor and the thermistor, and the thermistor is connected to ground; where the fourth switching device is configured to receive the temperature detection signal output by the control module and conduct the path of the thermistor to ground or the thermistor to the voltage dividing resistor in response to the temperature detection signal; the thermistor is configured to form a voltage dividing circuit with the voltage dividing resistor of the power supply module in the conducting case to generate a second voltage signal.

8. The temperature detection circuit according to any one of claims 1-5, characterized in that, The temperature detection circuit further includes a signal amplification module. The input end of the signal amplification module is respectively connected to the power supply module, the self-check module and the output end of the temperature detection module. The output end of the signal amplification module is connected to the control module; the signal amplification module is configured to amplify the first voltage signal or the second voltage signal to obtain an amplified voltage signal and output it to the control module; Correspondingly, the control module is configured to output a self-check signal or a temperature detection signal and receive the amplified voltage signal for circuit functional safety judgment or temperature calculation.

9. The temperature detection circuit according to claim 8, wherein, The signal amplification module includes a differential amplifier and a second resistor unit; the differential amplifier is configured to perform differential amplification processing on the first voltage signal or the second voltage signal to obtain an amplified voltage signal and output it to the control module; the second resistor unit is configured to set the gain and input impedance of the signal amplification module and determine the amplification factor of the differential amplifier.

10. The temperature detection circuit according to claim 9, characterized in that, The differential amplifier is an operational amplifier. The second resistor unit includes a second resistor, a third resistor, a fourth resistor and a fifth resistor; where the non-inverting input terminal of the operational amplifier is respectively connected to the power supply module, the self-check module and the output end of the temperature detection module through the third resistor; one end of the second resistor is connected to the non-inverting input terminal of the operational amplifier, and the other end of the second resistor is grounded; the inverting input terminal of the operational amplifier is connected to the output end of the operational amplifier through the fourth resistor, and the output end of the operational amplifier is connected to the control module; one end of the fifth resistor is connected to the inverting input terminal of the operational amplifier, and the other end of the fifth resistor is grounded.

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