A temperature detection circuit with functional safety

Abstract

The present application provides a temperature detection circuit with functional safety, which relates to the field of temperature detection technology. The circuit includes: a self-test module, a temperature detection module and a control module connected to each other, and a power supply module, the power supply module is connected to the self-test module and the temperature detection module respectively; the power supply module includes a power supply and a voltage divider resistor connected in sequence, which is used to provide voltage to the self-test module or the temperature detection module through the voltage divider resistor; the self-test module is used to turn on after responding to the self-test signal, and divide the voltage with the power supply module to generate a first voltage signal; the temperature detection module is used to turn on after responding to the temperature detection signal, and divide the voltage with the power supply module to generate a second voltage signal; the control module is used to output the self-test signal or the temperature detection signal, and receive the first voltage signal or the second voltage signal to perform circuit functional safety judgment or temperature calculation. The present application is used to ensure the reliability of the circuit and make the detection result more accurate.

Description

Technical Field

[0001] The present application relates to the field of temperature detection technology, and in particular to a temperature detection circuit with functional safety. Background Art

[0002] Temperature detection circuits are widely used in new energy vehicles, industrial control, and consumer electronics. Especially in the onboard environments of new energy vehicles, their reliability and functional safety directly impact the safe operation of the entire vehicle system. With the increasing adoption of functional safety standards, higher requirements are being placed on the diagnostic capabilities of circuits to ensure that abnormal conditions can be detected promptly and safety measures can be taken.

[0003] However, existing temperature detection solutions typically use a differential amplifier circuit to sample the thermistor's voltage divider signal. This signal is converted to a digital signal using an ADC (Analog to Digital Converter). The ambient temperature is then calculated based on the voltage divider ratio and a temperature-resistance table. While this solution is simple and cost-effective, circuit failures can lead to misjudgment of temperature information, posing a safety hazard. Consequently, existing solutions suffer from poor circuit reliability, resulting in inaccurate temperature information. Summary of the Invention

[0004] An embodiment of the present application provides a temperature detection circuit with functional safety, which is used to solve the problem of poor circuit reliability in existing solutions, thereby causing inaccurate detected temperature information.

[0005] In a first aspect, an embodiment of the present application provides a temperature detection circuit with functional safety, the temperature detection circuit comprising a self-test module, a temperature detection module, a control module, and a power supply module connected to each other, wherein the power supply module is connected to the self-test module and the temperature detection module respectively;

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

[0007] A control module, used for outputting a self-test signal or a temperature detection signal;

[0008] A self-test module is configured to be turned on after responding to a self-test signal output by the control module, and to perform voltage division with the power supply module to generate a first voltage signal;

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

[0010] The control module is further configured to receive the first voltage signal or the second voltage signal to perform circuit function safety judgment or temperature calculation.

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

[0012] a switch unit, configured to receive a self-test signal output by the control module and turn on the first resistance unit in response to the self-test signal;

[0013] The first resistor unit is used to form a voltage divider circuit with the voltage divider resistor of the power supply module when in conduction, so as to generate a first voltage signal.

[0014] In one possible 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 divider resistor and the first resistor unit, for receiving a first self-test signal output by the control module, and conducting a path between the voltage divider 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, for receiving a second self-test signal output by the control module, and conducting a 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.

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

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

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

[0018] After receiving the first voltage signal, the first voltage signal is compared with a preset voltage value, where the preset voltage value is determined based on the voltage divider resistor and the resistance value of the first resistance unit in the self-test module;

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

[0020] In one possible embodiment, the temperature detection module includes a fourth switch device and a thermistor, the fourth switch device is respectively connected to the control module, the thermistor and ground, and the thermistor is connected to the voltage divider resistor; or, the fourth switch device is respectively connected to the control module, the voltage divider resistor and the thermistor, and the thermistor is connected to the ground; wherein the fourth switch device is used to receive the temperature detection signal output by the control module, and in response to the temperature detection signal, conduct a path from the thermistor to the ground or from the thermistor to the voltage divider resistor; the thermistor is used to form a voltage divider circuit with the voltage divider resistor of the power supply module when it is conducted, to generate a second voltage signal.

[0021] In one possible embodiment, the temperature detection circuit also includes a signal amplification module, the input end of the signal amplification module is respectively connected to the output end of the power supply module, the self-test 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; accordingly, the control module is used to output a self-test signal or a temperature detection signal, and receive the amplified voltage signal to perform circuit function safety judgment or temperature calculation.

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

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

[0024] 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.

[0025] In one possible embodiment, 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-test module, and the temperature detection module respectively 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 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.

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

[0027] An embodiment of the present application provides a temperature detection circuit with functional safety, which includes a self-test module, a temperature detection module and a control module, and a power supply module that are interconnected, and the power supply module is connected to the self-test module and the temperature detection module respectively; the power supply module includes a power supply and a voltage divider resistor connected in sequence, which is used to provide voltage to the self-test module or the temperature detection module through the voltage divider resistor; the control module is used to output a self-test signal or a temperature detection signal; the self-test module is used to turn on after responding to the self-test signal output by the control module, and to divide the voltage with the power supply module to generate a first voltage signal; the temperature detection module is used to turn on after responding to the temperature detection signal output by the control module, and to divide the voltage with the power supply module to generate a second voltage signal; 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. Through the self-test module, the circuit can perform a self-test before or during operation to ensure the normal operation of each module, thereby improving the reliability of the circuit. The same power supply and voltage divider resistor are used to power the self-test and temperature detection modules, reducing the impact of component discreteness on the signal. At the same time, the control module dynamically switches the operating mode, isolates the risk of failure, and ensures the functional safety of the circuit and the accuracy of the temperature detection results. Therefore, the embodiment of the present application improves the functional safety and reliability of the circuit and ensures the accuracy of temperature information through the coordinated voltage divider mechanism of the self-test module and the temperature detection module. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0029] Figure 1 A schematic diagram of a temperature detection circuit with functional safety provided in this application Figure 1 ;

[0030] Figure 2 A schematic diagram of a temperature detection circuit with functional safety provided in this application Figure 2 ;

[0031] Figure 3 A schematic diagram of the specific structure of a temperature detection circuit with functional safety provided in this application Figure 1 ;

[0032] Figure 4 A schematic diagram of the specific structure of a temperature detection circuit with functional safety provided in this application Figure 2 .

[0033] Description of reference numerals:

[0034] Q1: third switching device; Q2: fourth switching device; Q3: second switching device; Q4: first switching device; R1: voltage divider resistor; R2: second resistor; R3: third resistor; R4: thermistor; R5: fourth resistor; R6: first resistor; R7: fifth resistor; VCC: power supply.

[0035] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0036] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain 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 this application and the above-mentioned drawings are intended to cover but not exclude inclusion. For example, a product or device comprising a series of components is not necessarily limited to those components explicitly listed, but may include other components not explicitly listed or inherent to these products or devices.

[0038] The term "module" as used in this application refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and / or software code that is capable of performing the functions associated with that element.

[0039] In the prior art, the temperature detection scheme usually uses a differential amplifier circuit to sample the voltage division signal of the thermistor, converts it into a digital signal through ADC, and then calculates the ambient temperature by combining the voltage division 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-test mechanism, and it is impossible to know in real time whether the working status of the temperature detection circuit is normal. When the circuit itself fails or is abnormal, the system cannot detect and alarm in time, which will lead to misjudgment of temperature information and cause safety hazards. Especially in the on-board electronic systems 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-test capability to solve the problem of poor circuit reliability in the existing scheme, which leads to inaccurate detected temperature information.

[0040] To address the above-mentioned issues, an embodiment of the present application provides a temperature detection circuit with functional safety. Through a self-test module, the circuit can perform self-tests before or during operation. When the self-test module is turned on, the module forms a fixed voltage divider circuit with a voltage divider resistor and generates a first voltage signal. The control module can identify circuit faults by analyzing the first voltage signal, ensuring the normal operation of each module, thereby improving the reliability of the circuit. When the temperature detection module is turned on, the voltage divider resistor forms a variable voltage divider circuit with the thermistor in the module and generates a second voltage signal. The control module generates temperature information by analyzing the second voltage signal, thereby ensuring the accuracy of the temperature information. Furthermore, by using the same power supply and voltage divider resistor to provide a stable voltage for the self-test module and the temperature detection module, and selecting the voltage divider path through signal switching (self-test signal / temperature detection signal) of the control module, hardware resource reuse can be achieved, redundant components can be reduced, and circuit complexity and cost can be reduced.

[0041] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0042] Figure 1 A schematic diagram of a temperature detection circuit with functional safety provided in this application Figure 1 , can be applied to new energy vehicles, automotive electronics, industrial control or consumer electronics and other fields. Figure 1 As shown, the temperature detection circuit includes: a self-test module, a temperature detection module and a control module connected to each other, and a power supply module, the power supply module being connected to the self-test module and the temperature detection module respectively; the power supply module including a power supply and a voltage divider resistor connected in sequence, for providing voltage to the self-test module or the temperature detection module through the voltage divider resistor; a control module for outputting a self-test signal or a temperature detection signal; the self-test module is configured to be turned on after responding to the self-test signal output by the control module, and to perform voltage division with the power supply module to generate a first voltage signal; the temperature detection module is configured to be turned on after responding to the temperature detection signal output by the control module, and to perform voltage division with the power supply module to generate a second voltage signal; the control module is further configured to receive the first voltage signal or the second voltage signal to perform circuit function safety judgment or temperature calculation.

[0043] In this embodiment, the self-test module is used to perform a functional self-test at circuit startup or at specific times to ensure that all circuit components are functioning properly. This module may include a series of switching devices and resistors that can be turned on under the control module's command and form a voltage divider circuit with the voltage divider resistors in the power supply module to generate a fixed voltage signal, namely a first voltage signal, at the voltage divider point (i.e., the detection point connected to the control module). The control module analyzes this signal, such as comparing it with a preset value, to determine the circuit's functional safety, such as whether the circuit is in a normal state.

[0044] The temperature detection module can be a circuit used to monitor the temperature of the environment or the inside of the device in real time. It usually includes a thermistor, whose resistance changes with temperature. The thermistor can be selected from suitable thermistor materials based on application requirements. For example, negative temperature coefficient thermistors or positive temperature coefficient thermistors from the new materials industry can be used. They have advantages such as fast response speed, high sensitivity, and low cost in temperature detection, further improving the efficiency of temperature detection. Under the command of the control module, the temperature detection module is turned on and forms a voltage divider circuit with the voltage divider resistor in the power supply module to generate a temperature-related voltage signal at the voltage divider point, namely the second voltage signal. After processing, this signal can be used to calculate the current temperature.

[0045] The control module coordinates and controls the operation of the self-test module and the temperature detection module, processing signals and making decisions. Furthermore, the control module outputs a self-test signal or a temperature detection signal, receives voltage signals from the temperature detection module or the self-test module, and uses these signals to determine circuit functional safety or calculate temperature. It then 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, responsible for collecting voltage signals and outputting control signals such as the self-test signal and the temperature detection signal.

[0046] The power supply module includes a power supply and a voltage divider resistor, which can provide operating voltage for the self-test module and the temperature detection module, and participate in the voltage division calculation.

[0047] The self-test signal and temperature detection signal can refer to logic-level signals output by the control module. The self-test signal is used to trigger the circuit into a functional safety self-test mode to verify the normal operation of the temperature detection circuit; the temperature detection signal is used to switch the circuit back to normal operation mode to implement the temperature measurement function. Furthermore, triggering conditions or rules for the self-test and normal operation modes can be pre-set in the control module. For example, the self-test mode can be automatically triggered at system startup to ensure the circuit is in a normal state before the system begins normal operation. Alternatively, the user can manually trigger the self-test mode through a specific operation (such as a specific key combination) to detect potential circuit issues during system operation. The self-test mode can also be triggered by specific events (such as the system detecting an abnormal signal or power supply fluctuation) or at specific times (set a timer) to ensure the long-term stability and reliability of the system circuit. Accordingly, normal operation mode is typically triggered after the system boots up and completes the self-test; it can also be triggered by specific user operations or external control signals.

[0048] The level signal can include multiple high-level and low-level combinations to control the on / off state of the switch circuit. The number of level signals depends on the number of switching devices the circuit needs to control in either the functional safety self-test mode or the normal operating mode. For example, during a self-test, if the circuit needs to open two independently controlled switches and close one, the self-test signal will include two high-level signals and one low-level signal. If, during a temperature detection process, the circuit needs to close two independently controlled switches and open one, the temperature detection signal will include two low-level signals and one high-level signal.

[0049] Since the voltage signals output by the self-test module and the temperature detection module are usually weak, optionally, before the control module receives the first voltage signal or the second voltage signal, the voltage signal can be amplified to improve the accuracy of the signal read by the control module. Figure 2 A schematic diagram of a temperature detection circuit with functional safety provided in this application Figure 2 ,like Figure 2 As shown, a signal amplification module is added between the control module and the self-test module and temperature detection module to amplify the voltage signals output by the self-test module and the temperature detection module. This improves the accuracy of the voltage signal reading by the control module and enables more accurate processing of the voltage signal by the control module, thereby achieving precise self-test and temperature detection. This embodiment does not impose any particular restrictions on the structure of the signal amplification module, as long as it can achieve the voltage signal amplification function.

[0050] The embodiment of the present application provides a temperature detection circuit with functional safety. Through a self-test module, the circuit can perform self-tests before or during operation. When the self-test module is turned on, the module forms a fixed voltage divider circuit with a voltage divider resistor and generates a first voltage signal. The control module can identify circuit faults by analyzing the first voltage signal, ensuring the normal operation of each module, thereby improving the reliability of the circuit. When the temperature detection module is turned on, the voltage divider resistor forms a variable voltage divider circuit with the thermistor in the module and generates a second voltage signal. The control module generates temperature information by analyzing the second voltage signal, thereby ensuring the accuracy of the temperature information. In addition, the same power supply and voltage divider resistor are used to provide a stable voltage for the self-test module and the temperature detection module. The voltage divider path is selected by signal switching (self-test signal / temperature detection signal) of the control module, which can achieve hardware resource reuse, reduce redundant components, and reduce circuit complexity and cost.

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

[0052] The switch unit may refer to an electronic switch component controlled by a self-test signal, and may include one or more switch components, configured to open or close the current path of the self-test module based on the state of the signal (e.g., high level or low level). For example, the switch unit may include a high-side switch, a low-side switch, or other logic-controlled switch (e.g., a MOSFET or relay).

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

[0054] It should be noted that, in normal working 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 to shut down the first resistor unit in response to the temperature detection signal, so as to avoid the first resistor unit interfering with or affecting the voltage division between the temperature detection module and the power supply module in normal working mode.

[0055] The introduction of the switch unit makes the self-test process more flexible and controllable. The voltage divider circuit formed by the first resistor unit and the power supply module's voltage divider resistor generates a stable and predictable first voltage signal for circuit functional safety assessment. The switch unit ensures stable on / off switching of the self-test path, preventing false operation and improving the temperature detection circuit's self-test accuracy and reliability. This helps to promptly detect and eliminate circuit faults, ensuring accurate and stable temperature detection.

[0056] Based on the above 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 divider resistor and the first resistor unit, and is used to receive the first self-test signal output by the control module, and to connect the path between the voltage divider 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 to connect 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 may refer to a type of switch unit, such as a PNP transistor used as a high-side switch, connected between the voltage divider 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, upon receiving the signal, conducting a path between the voltage divider resistor and the first resistor unit.

[0058] The low-side switch unit may refer to another type of switch unit, such as an NPN transistor used as a low-side switch, connected between the first resistor unit and ground. The low-side switch unit is responsible for receiving the second self-test signal output by the control module and, upon receiving the second self-test signal, conducting a path between the first resistor unit and ground.

[0059] The first self-test signal and the second self-test signal are signals output by the control module for controlling the high-side switch unit and the low-side switch unit to be turned on or off. 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 the low-side switch unit.

[0061] It should be noted that, in normal operating 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 shut down the corresponding connection path, so as to avoid the first resistance unit interfering with or affecting the voltage division between the temperature detection module and the power supply module in normal operating mode.

[0062] Figure 3 A schematic diagram of the specific structure of a temperature detection circuit with functional safety provided in this application Figure 1 ,like Figure 3 As shown, its switching unit includes a low-side switch unit, namely the third switch device Q1. In self-test mode, GPIO1 is the second self-test signal. GPIO1 sends a high-level signal to the third switch device Q1, connecting the first resistor unit (corresponding to the first resistor R6) and the voltage-dividing resistor R1 to generate a first voltage signal. 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 normal operating mode, GPIO1 is the temperature detection signal. GPIO1 sends a low-level signal to the third switch device Q1, disconnecting the first resistor unit (corresponding to the first resistor R6) and the voltage-dividing resistor R1.

[0063] Flexible configuration of high-side and / or low-side switch units adapts to different circuit layout requirements and achieves reliable on / off control of the self-test circuit. The high-side switch ensures controllable power supply side and prevents abnormal power supply; the low-side switch provides redundant ground paths, ensuring reliable grounding and doubly protecting circuit safety.

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

[0065] The switching device in this embodiment can be a transistor (such as a triode, MOSFET, or BJT), or another switch that is turned on or off based on a control signal, such as a relay, and is used to connect or disconnect the circuit containing the first resistor and the voltage divider resistor in response to the control signal. The first resistor is a specific implementation of the first resistance unit, and together with the voltage divider resistor, it forms a voltage divider circuit for generating the first voltage signal during self-test.

[0066] In some embodiments, the switching devices in the switch unit are MOS tubes and / or triodes. Among them, the switching devices in the switch unit can all be MOS tubes, or all can be triodes. When there are multiple switching devices, they can also be a combination of MOS tubes and triodes. Furthermore, the high-side switch is usually a P-channel MOS tube and / or an N-channel MOS tube and / or a PNP triode and / or an NPN triode, and the low-side switch is usually an N-channel MOS tube and / or an NPN triode. Generally, MOS tubes are more suitable for high-precision, low-power scenarios, and triodes are more suitable for low-cost, strong anti-interference scenarios. Engineers can freely choose the device type according to cost, power consumption, speed and other requirements.

[0067] Figure 4 A schematic diagram of the specific structure of a temperature detection circuit with functional safety provided in this application Figure 2 ,like Figure 4 As shown, in some 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 switch device Q4 and a second switch device Q3, the low-side switch unit includes a third switch device Q1, and the first resistor unit includes a first resistor R6; wherein, the first end of the first switch device Q4 is connected to the control module, the second end of the first switch device Q4 is connected to the first end of the second switch device Q3, and the third end of the first switch device Q4 is grounded; the second end of the second switch device Q3 is connected to one end of the voltage divider resistor R1, and the third end of the second switch 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 switch device Q1; the first end of the third switch device Q1 is connected to the control module, and the third end of the third switch device Q1 is grounded.

[0068] In the self-test mode, GPIO3 is the first self-test signal (high-level signal) to turn on the first switching device Q4 and the second switching device Q3, and GPIO1 is the second self-test signal (high-level signal) to turn on the third switching device Q1; in the normal working 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] Wherein, the first switching device Q4 and the third switching device Q1 are NPN transistors, with the first terminal being the base, the second terminal being the collector, and the third terminal being the emitter. In some examples, N-channel MOSFETs may also be used. The second switching device Q3 is a PNP transistor, with the first terminal being the base, the second terminal being the emitter, and the third terminal being the collector. In some examples, P-channel MOSFETs may also be used.

[0070] The cascade structure of the high-side switch unit's two-stage devices ensures stable conduction of the high-side switch under high currents. The low-side switch unit, consisting of a single switching device, reduces power consumption in the control circuit. Furthermore, the switch unit is compatible with both triode devices and MOSFETs, meeting varying voltage / current requirements. This allows the self-test circuit to more precisely control the circuit's on and off states, thereby improving its accuracy and reliability.

[0071] Based on the above embodiment, the control module is also used to: after receiving the first voltage signal, compare the first voltage signal with a preset voltage value, and the preset voltage value is determined based on the voltage divider resistor and the resistance value of the first resistance unit in the self-test module; if the first voltage signal is different from the preset voltage value, output a circuit fault signal.

[0072] The preset voltage value is a standard voltage value pre-set based on voltage divider circuit theory, the resistance values ​​of the voltage divider resistors, and the first resistance unit in the self-test module, for comparison with the first voltage signal. In one example, during circuit design, engineers calculate the expected voltage value based on the resistance values ​​of the voltage divider resistors and the first resistance unit and store this value as the preset voltage value in the control module. Furthermore, the control module receives the first voltage signal from the self-test module via 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 assumes that the detection circuit is operating normally and does not perform any special operations. If the first voltage signal differs from the preset voltage value (e.g., the values ​​are inconsistent or outside the allowable error range), the control module assumes that the circuit is faulty and subsequently outputs a circuit fault signal.

[0073] Optionally, the output form of the circuit fault signal can be a logic level signal (such as a GPIO output low level), a PWM alarm signal, a bus communication message (such as a CAN bus error frame), etc. The corresponding system of the circuit can respond to the fault based on the signal, such as triggering a system reset, lighting a fault indicator light, recording an error log, etc.

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

[0075] Based on the above embodiment, the temperature detection module includes a fourth switch device and a thermistor, the fourth switch device is respectively connected to the control module, the thermistor and ground, and the thermistor is connected to the voltage divider resistor; or the fourth switch device is respectively connected to the control module, the voltage divider resistor and the thermistor, and the thermistor is connected to the ground; wherein the fourth switch device is used to receive the temperature detection signal output by the control module and, in response to the temperature detection signal, conduct a path from the thermistor to the ground or from the thermistor to the voltage divider resistor; the thermistor is used to form a voltage divider circuit with the voltage divider resistor of the power supply module when it is conducted, to generate a second voltage signal.

[0076] The fourth switch device may be a transistor (such as a triode, MOSFET, or BJT), or another switch that is turned on or off based on a control signal, such as a relay, and is used to turn on or off the circuit where the thermistor and the voltage divider resistor are located according to the control signal.

[0077] In this embodiment, it is understood that with the rapid development of the new energy vehicle industry, various systems of new energy vehicles (such as onboard electronic systems, battery management systems, charging systems, motor control systems, etc.) need to perform real-time temperature detection to ensure the safety and reliability of the vehicle. Thermistors, as thermal elements with temperature detection functions in the new materials industry, are suitable for various occasions requiring precise temperature measurement and control. Therefore, the embodiments of this application can adopt negative temperature coefficient thermistors or positive temperature coefficient thermistors in the new materials industry to provide reliable temperature data support for various systems of new energy vehicles (such as onboard electronic systems).

[0078] The second voltage signal is generated by the thermistor and the voltage divider resistor forming a voltage divider circuit. It is output at the voltage divider point between the thermistor and the voltage divider resistor. This signal reflects the resistance value of the thermistor and, by extension, the temperature. Furthermore, when the thermistor's resistance value changes, the output voltage of the voltage divider circuit (i.e., the second voltage signal) also changes accordingly. This signal is captured by the control module and converted into a temperature value or processed in other ways through a preset internal circuit or algorithm.

[0079] In order to prevent the thermistor from interfering with the first voltage signal output by the self-test module during the self-test process, resulting in a large error between the actual voltage signal and the preset voltage value, in the self-test mode, the fourth switching device is also used to receive the self-test signal (low-level signal) output by the control module, and in response to the self-test signal, cut off the path from the thermistor to ground or from the thermistor to the voltage divider resistor.

[0080] Continue to refer to Figure 3 and Figure 4The first end of the fourth switch device Q2 (e.g., the base of an NPN transistor) is connected to the control module, the second end of the fourth switch device Q2 (e.g., the collector of an NPN transistor) is connected to one end of the thermistor R4, the third end of the fourth switch device Q2 (e.g., the emitter of an NPN transistor) is connected to ground, and the other end of the thermistor R4 is connected to one end of a voltage divider resistor R1. The voltage divider point corresponding to the second voltage signal is between the thermistor R4 and the voltage divider resistor R1. In self-test mode, GPIO2 is a self-test signal (a low-level signal) that turns off the fourth switch device Q2. In normal operating mode, GPIO2 is a temperature detection signal (a high-level signal) that turns on the fourth switch device Q2.

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

[0082] Based on the above embodiments, Figure 2 The temperature detection circuit also includes a signal amplification module, the input end of the signal amplification module is respectively connected to the output end of the power supply module, the self-test 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; accordingly, the control module is used to output a self-test signal or a temperature detection signal, and receive the amplified voltage signal to perform circuit function safety judgment or temperature calculation.

[0083] It is understandable that the signal amplification module can be a circuit including an operational amplifier, which can be set according to the actual circuit conditions and detection requirements. In the self-test mode, the signal amplification module receives the first voltage signal output by the self-test module, amplifies the first voltage signal, generates a corresponding amplified voltage signal and outputs it to the control module; after receiving the amplified voltage signal, the control module makes a circuit function safety judgment based on this signal (such as whether the detection circuit is working properly). In the normal working mode, the signal amplification module receives the second voltage signal output by the temperature detection module, amplifies the second voltage signal, generates a corresponding amplified voltage signal and outputs it 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-divided signal is amplified to the optimal detection range of the control module's detection interface (such as ADC), improving the circuit's ability to detect weak signals and enhancing the accuracy of circuit functional safety judgment and temperature detection.

[0085] Based on the above embodiment, the signal amplification module includes a differential amplifier and a second resistance 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 resistance 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 capable of amplifying the difference between two input signals. It is often used to amplify weak signals and is composed of various circuit components, including but not limited to operational amplifiers. In a temperature detection circuit, the differential amplifier is used to differentially amplify a first voltage signal or a second voltage signal to generate an amplified voltage signal. For example, the differential amplifier can be an integrated circuit chip, such as an LM741 or OP07. These amplifiers feature high gain, low noise, and high input impedance, making them suitable for precision analog signal processing.

[0087] In addition, the second resistance unit may include multiple feedback resistors and input resistors. By adjusting the resistance values ​​of these resistors, the gain and input impedance of the differential amplifier 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 circuit's response ability to the input signal.

[0088] In addition, under normal circumstances, the signal amplification module uses a single-stage differential amplifier circuit, that is, a 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 power or gain of the single-stage differential amplifier circuit does not meet the requirements, a second differential amplifier circuit can be added after it to achieve multi-stage amplification of the signal. For example, in scenarios where weak signals need to be amplified or signal driving capabilities need to be improved, each additional differential amplifier circuit can further improve the circuit's gain and signal quality.

[0089] The differential amplifier enables the circuit to accurately perform differential amplification on weak first or second voltage signals, thereby improving the signal's anti-interference capability and transmission efficiency. Furthermore, the second resistor unit allows the circuit to flexibly adjust gain and input impedance to meet the practical 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 used in various applications requiring precise temperature monitoring.

[0090] Based on the above embodiment, 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-test module and the temperature detection module respectively 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 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, continue to refer 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 operational amplifier) ​​is connected to one end of R1 in the power supply module, one end of R6 in the self-test module or the second end of Q3, and one end of R4 in the temperature detection module through the third resistor R3; 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 operational amplifier), 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 operational amplifier) ​​is connected to the output terminal of the operational amplifier (i.e., the "OUT1" terminal of the operational amplifier) ​​through the fourth resistor R5, and the output terminal of the operational amplifier (i.e., the "OUT1" terminal of the operational amplifier) ​​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 operational amplifier), 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 between the fourth resistor R5 and the fifth resistor R7.

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

[0094] Below Figure 3 and Figure 4 Taking the example of FIG1 as an example, the structure and working principle of a temperature detection circuit with functional safety in an embodiment of the present application are further explained. The temperature detection circuit includes: a power supply module, a self-test module, a temperature detection module, a signal amplification module and a control module, wherein:

[0095] 1. Power supply module: including power supply VCC and voltage divider resistor R1.

[0096] 2. If Figure 3 The self-test module shown includes: a low-side switch composed of a third switch device Q1 and a first resistor R6. The third switch device Q1 is connected to the control module and receives a GPIO1 control signal sent by the control module.

[0097] like Figure 4 The self-test module shown includes a high-side switch consisting of a first switch Q4 and a second switch Q3, a low-side switch consisting of a third switch Q1, and a first resistor R6. The first switch Q4 is connected to the control module and receives a GPIO3 control signal from the control module, while the third switch Q1 is connected to the control module and receives a GPIO1 control signal from the control module.

[0098] 3. The temperature detection module includes: a thermistor R4 and a fourth switch device Q2. The fourth switch 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 op amp, a second resistor R2, a third resistor R3, a fourth resistor R5, and a fifth resistor R7. According to the principle of differential amplification circuits, the resistance values ​​of the second resistor R2 and the fourth resistor R5 are equal, and the resistance values ​​of the third resistor R3 and the fifth resistor R7 are equal. The amplification factor is equal to the ratio of the fourth resistor R5 to the fifth resistor R7.

[0100] 5. The control module includes an MCU control chip, which is used to collect analog voltage signals and output control signals. The control module's ADC interface is used to collect the amplified voltage signal (voltage value) output by the signal amplifier module. When in self-test mode, the control module outputs a control signal (self-test signal) with GPIO1 and GPIO3 set to high and GPIO2 set to low. When in normal operation mode, the control module outputs a control signal (temperature detection signal) with GPIO1 and GPIO3 set to low and GPIO2 set to high.

[0101] like Figure 3The operating principle of the temperature detection circuit shown is as follows: when the control module outputs a self-test signal, it enters self-test mode. GPIO1 is high, the low-side switch is turned on, and the voltage divider circuit establishes VCC-R1-R6-ground. The self-test module outputs a first voltage signal (i.e., a fixed voltage value corresponding to the voltage divider point between the voltage divider resistors R1 and R6) divided by the voltage divider resistors R1 and R6. This signal is input to the signal amplification module, where it undergoes differential amplification to generate an amplified voltage signal, which is then output to the ADC interface of the control module. When the amplified voltage signal detected by the control module matches a preset voltage value, the temperature detection circuit is determined to be in a normal state, completing the self-test of the detection circuit. When the amplified voltage signal does not match the preset voltage value, a circuit fault signal is output. Furthermore, when GPIO2 is low, the fourth switch device Q2 is turned off, disconnecting thermistor R4 and preventing it from affecting the fixed voltage value output by the self-test module.

[0102] When the control module outputs a temperature detection signal, it enters normal operating mode, wherein GPIO1 is a low-level signal, GPIO2 is a high-level signal, the fourth switch device Q2 is turned on, the low-side switch is turned off, and the voltage divider circuit is established as VCC-R1-R4-ground. The temperature detection module will output a second voltage signal obtained by dividing the voltage by the voltage divider resistor R1 and the thermistor R4 (i.e., the voltage value corresponding to the voltage dividing point between the voltage divider 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 determine the current temperature based on the temperature-resistance correspondence table of the thermistor R4.

[0103] like Figure 4 The operating principle of the temperature detection circuit shown is as follows: when the control module outputs a self-test signal, it enters self-test mode. GPIO1 and GPIO3 are both high-level signals, the high-side switch and the low-side switch are both on, and the voltage divider circuit is established as VCC-R1-R6-ground. The self-test module outputs a first voltage signal (i.e., a fixed voltage value corresponding to the voltage divider point between the voltage divider resistor R1 and the first resistor R6) divided by the voltage divider resistor R1 and the first resistor R6. This signal is input to the signal amplification module, where it undergoes differential amplification to generate an amplified voltage signal, which is then output to the ADC interface of the control module. When the amplified voltage signal detected by the control module matches the preset voltage value, the temperature detection circuit is determined to be in a normal state, completing the self-test of the detection circuit. When the amplified voltage signal does not match the preset voltage value, a circuit fault signal is output. Furthermore, when GPIO2 is low-level, the fourth switch device Q2 is turned off, disconnecting the thermistor R4 and preventing the thermistor R4 from affecting the fixed voltage value output by the self-test module.

[0104] When the control module outputs a temperature detection signal, it enters a normal operating mode, wherein GPIO1 and GPIO3 are both low-level signals, GPIO2 is a high-level signal, the fourth switch device Q2 is turned on, the high-side switch and the low-side switch are both turned off, and the voltage divider circuit is established as VCC-R1-R4-ground. The temperature detection module will output a second voltage signal obtained by dividing the voltage by the voltage divider resistor R1 and the thermistor R4 (i.e., the voltage value corresponding to the voltage dividing point between the voltage divider 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 obtain the current temperature based on the temperature-resistance correspondence table of the thermistor R4.

[0105] The functionally safe temperature detection circuit provided in the embodiments of the present application includes a self-test mode and a normal operating mode. This circuit can self-test the reliability of the detection circuit and promptly detect any anomalies, thereby improving the reliability and intelligence of the circuit. Furthermore, the circuit has the advantages of a simple and reliable circuit system, requiring few peripheral components, and being low-cost.

[0106] The present application also provides a server including the temperature detection circuit with functional safety in various possible embodiments described above. In this embodiment, the specific definition of the server can be found in the definition of the temperature detection circuit with functional safety described above, and will not be repeated here.

[0107] It should be noted that the various modules or component structures that may be involved in the server can be implemented in whole or in part through software, hardware, or a combination thereof. Each module or component structure can be embedded in or independent of the processor in the display device in hardware form, or can be stored in the memory of the display device in software form, so that the processor can call and execute the corresponding operations of the above server.

[0108] It is understood that the various numerical numbers involved in the embodiments of the present application are only for the convenience of description and are not intended to limit the scope of the embodiments of the present application. In the embodiments of the present application, the order of the sequence numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0109] Finally, it should be noted that those skilled in the art will readily identify 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 that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The present invention is not limited to the precise structure described above and illustrated in the accompanying drawings, and various modifications and variations may be made without departing from the scope thereof. The scope of the present invention is limited solely by the appended claims.

Claims

1. A temperature detection circuit with functional safety, characterized in that: The temperature detection circuit includes a self-test module, a temperature detection module and a control module, which are connected to each other, and a power supply module, wherein the power supply module is connected to the self-test module and the temperature detection module respectively; The power supply module includes a power supply and a voltage divider resistor connected in sequence, and is used to provide voltage to the self-test module or the temperature detection module through the voltage divider resistor; The control module is used to output a self-test signal or a temperature detection signal; The self-test module is configured to be turned on in response to the self-test signal output by the control module, and to perform voltage division with the power supply module to generate a first voltage signal; The temperature detection module is configured to be turned on in response to the temperature detection signal output by the control module, and to perform voltage division with the power supply module to generate a second voltage signal; The control module is further configured to receive the first voltage signal or the second voltage signal to perform circuit function safety determination or temperature calculation; Wherein, the self-test module includes a switch unit and a first resistance unit; The switch unit is configured to receive a self-test signal output by the control module and turn on the first resistance unit in response to the self-test signal; The first resistor unit is configured to form a voltage divider circuit with the voltage divider resistor of the power supply module when in conduction, to generate a first voltage signal; 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 resistance unit, and is used to receive the first self-test signal output by the control module, and to connect the path between the voltage-dividing resistor and the first resistance 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 to open a path between the first resistor unit and the ground in response to the second self-test signal; The self-test signal includes a first self-test signal and / or a second self-test signal.

2. The temperature detection circuit according to claim 1, 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 switch device and a second switch device, the low-side switch unit includes a third switch device, and the first resistor unit includes a first resistor; wherein, A first end of the first switch device is connected to the control module, a second end of the first switch device is connected to a first end of the second switch device, and a third end of the first switch device is grounded; The second end of the second switch device is connected to one end of the voltage dividing resistor, and the third end of the second switch 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; A first end of the third switch device is connected to the control module, and a third end of the third switch device is grounded.

3. The temperature detection circuit according to claim 2, wherein: The switching devices in the switching unit are MOS tubes and / or triodes.

4. The temperature detection circuit according to any one of claims 1 to 3, characterized in that: The control module is further configured to: After receiving the first voltage signal, comparing the first voltage signal with a preset voltage value, the preset voltage value being determined according to the voltage divider resistor and the resistance value of the first resistance unit in the self-test module; If the first voltage signal is different from the preset voltage value, a circuit fault signal is output.

5. The temperature detection circuit according to any one of claims 1 to 3, characterized in that: The temperature detection module includes a fourth switch device and a thermistor, wherein the fourth switch device is connected to the control module, the thermistor and the ground respectively, and the thermistor is connected to the voltage divider resistor; or, the fourth switch device is connected to the control module, the voltage divider resistor and the thermistor respectively, and the thermistor is connected to the ground; wherein, The fourth switch device is configured to receive the temperature detection signal output by the control module and, in response to the temperature detection signal, conduct a path from the thermistor to the ground or from the thermistor to the voltage divider resistor; The thermistor is used to form a voltage divider circuit with the voltage divider resistor of the power supply module when it is turned on, so as to generate a second voltage signal.

6. The temperature detection circuit according to any one of claims 1 to 3, 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 output ends of the power supply module, the self-test module and the temperature detection module, and the output end of the signal amplification module is connected to the control module; The signal amplifying module is configured to amplify the first voltage signal or the second voltage signal to obtain an amplified voltage signal, and output the amplified voltage signal to the control module; Accordingly, The control module is used to output a self-test signal or a temperature detection signal, and receive the amplified voltage signal to perform circuit function safety judgment or temperature calculation.

7. The temperature detection circuit according to claim 6, characterized in that: The signal amplification module includes a differential amplifier and a second resistance 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 the amplified voltage signal to the control module; The second resistance unit is used to set the gain and input impedance of the signal amplification module and determine the amplification factor of the differential amplifier.

8. The temperature detection circuit according to claim 7, characterized in that: 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-test module and the temperature detection module respectively 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 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.

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