Temperature detection circuit

Abstract

The utility model discloses a temperature detection circuit. The device specifically comprises a voltage division module, an amplification module, a temperature sensor and a main control chip, the input end of the voltage dividing module is connected with the positive electrode of the first power supply, the output end of the voltage dividing module is connected with the first end of the temperature sensor, and the second end of the temperature sensor is connected with the reference voltage end; the input end of the amplification module is connected with the output end of the voltage division module, and the output end of the amplification module is connected with the main control chip. According to the embodiment of the invention, the precision of the temperature detected by the temperature sensor can be improved.

Description

Technical Field

[0001] The present application relates to a temperature detection circuit, and in particular to a temperature detection circuit based on a temperature sensor. Background Art

[0002] At present, multiple components in electric vehicle domain controllers need to be thermally managed, such as motor temperature, AC / DC charging port temperature, and battery pack water inlet and outlet temperature. The above temperatures are all detected by temperature sensors, which are temperature-sensitive electronic components with different resistance values ​​at different temperatures. Usually, in the detection circuit, it is necessary to connect voltage-dividing resistors with different resistance values ​​in series with the temperature sensor for voltage division. In actual applications, the resistance value of the temperature sensor spans a large range, and voltage-dividing resistors with larger resistance values ​​are often selected, resulting in the voltage value at the pin of the main control chip in the detection circuit not being able to meet the temperature detection accuracy of the main control chip, resulting in low temperature accuracy detected by the temperature sensor. Utility Model Content

[0003] The embodiment of the present application provides a temperature detection circuit, which can improve the temperature accuracy detected by a temperature sensor.

[0004] In a first aspect, an embodiment of the present application provides a temperature detection circuit, comprising:

[0005] Voltage divider module, amplifier module, temperature sensor and main control chip;

[0006] The input end of the voltage divider module is connected to the positive electrode of the first power supply, the output end of the voltage divider module is connected to the first end of the temperature sensor, and the second end of the temperature sensor is connected to the reference voltage end;

[0007] The input end of the amplifying module is connected to the output end of the voltage dividing module, and the output end of the amplifying module is connected to the main control chip.

[0008] In the embodiment of the present application, a voltage divider module, an amplification module, a temperature sensor and a main control chip are arranged in the temperature detection circuit, wherein the voltage divider module plays a role of voltage division in the temperature detection circuit, and the amplification module can amplify the voltage at the pin of the main control chip so that the voltage value at the pin of the main control chip satisfies the temperature detection accuracy of the main control chip, thereby improving the temperature detection accuracy of the entire temperature detection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0010] Figure 1A schematic diagram of an exemplary temperature detection circuit provided for one embodiment of the present application.

[0011] Figure 2 A schematic diagram of a temperature detection circuit provided in accordance with an embodiment of the present application.

[0012] Figure 3 A schematic diagram of another temperature detection circuit provided by an embodiment of the present application. DETAILED DESCRIPTION

[0013] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0014] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0015] At present, multiple components in electric vehicle domain controllers need to be thermally managed, such as motor temperature, AC / DC charging port temperature, and battery pack inlet and outlet temperature. The temperature ranges of the above-mentioned different components are different, and appropriate temperature sensors are often selected according to the temperature range of different parts to be tested. Commonly used temperature sensor models may be PT100 or NTC-100k.

[0016] like Figure 1 The current temperature detection circuit is often composed of a voltage-dividing resistor R, a temperature sensor T and a main control chip. The first end of the voltage-dividing resistor R is connected to the positive pole of the power supply V, the second end of the voltage-dividing resistor R is connected to the first end of the temperature sensor T, the second end of the temperature sensor is connected to the reference voltage end, and the second end of the voltage-dividing resistor R is also connected to the main control chip.

[0017] As a temperature-sensitive electronic component, the temperature sensor will show different resistance values ​​at different temperatures. In the detection circuit, the appropriate voltage divider resistor R is often selected according to the resistance range of the temperature sensor. For example, the resistance of the PT100 temperature sensor may be 100Ω at 0℃; at 100℃, the resistance may be 140Ω. When selecting the appropriate voltage divider resistor R for PT100, a resistor with a resistance value of 100Ω may be selected to be connected in series with the PT100 temperature sensor.

[0018] It is conceivable that in Figure 1 In the temperature detection circuit, the resistance of the temperature sensor T is variable, and the resistance of the voltage divider resistor R connected in series with it is also variable. The change of the resistance of the voltage divider resistor R and the temperature sensor T in the circuit causes the voltage value at the pin of the main control chip to change accordingly. For the temperature sensor with a large resistance span, the voltage value at the pin of the main control chip cannot meet the temperature detection accuracy of the main control chip. The accuracy of the component temperature detected by the temperature sensor is low, which affects the normal use of the vehicle.

[0019] Therefore, an embodiment of the present application provides a temperature detection circuit that can solve the above problems.

[0020] like Figure 2 As shown, an embodiment of the present application provides a temperature detection circuit, including:

[0021] A voltage divider module 201, an amplifying module 202, a temperature sensor 203 and a main control chip 204; the input end of the voltage divider module 201 is connected to the positive pole of the first power supply V1, the output end of the voltage divider module 201 is connected to the first end of the temperature sensor 203, and the second end of the temperature sensor 203 is connected to the reference voltage end GND; the input end of the amplifying module 202 is connected to the output end of the voltage divider module 201, and the output end of the amplifying module 202 is connected to the main control chip 204.

[0022] In such Figure 2 In the circuit shown, the voltage divider module 201 is connected in series with the temperature sensor 203. In the loop of the first power supply-voltage divider module 201-temperature sensor 203, the voltage divider module 201 mainly plays the role of dividing the voltage for the temperature sensor 203. A variable resistor with a variable resistance value can be set in the voltage divider module 201. For example, multiple resistors with different resistance values ​​can be selected for parallel connection, and the resistance value of the voltage divider module 201 can be adjusted by adjusting the number of different parallel branches.

[0023] like Figure 2In the embodiment of the present application, an amplification module 202 is further provided in the temperature detection circuit. The amplification module 202 is connected in series with the main control chip 204 and is mainly used to amplify the voltage at the pin of the main control chip 204. A device capable of amplifying the voltage may be provided in the amplification module, such as an amplifier. An operational amplifier may be selected here, which can amplify the voltage at the pin of the main control chip 204 by multiples so that it meets the detection accuracy of the main control chip 204 for the temperature.

[0024] In the embodiment of the present application, a voltage divider module, an amplification module, a temperature sensor and a main control chip are arranged in the temperature detection circuit, wherein the voltage divider module plays a role of voltage division in the temperature detection circuit, and the amplification module can amplify the voltage at the pin of the main control chip. In the embodiment of the present application, two functional modules, the voltage divider module and the amplification module, are used to adjust the voltage at the pin of the main control chip, so that the voltage value at the pin of the main control chip can meet the temperature detection accuracy of the main control chip, thereby improving the temperature detection accuracy of the entire temperature detection circuit.

[0025] In some embodiments, Figure 3 The voltage divider module 201 includes a first resistor R1 and at least one voltage divider submodule 2011; the first end of the first resistor R1 is connected to the positive electrode of the first power supply V1, and the second end of the first resistor R1 is connected to the first end of the temperature sensor 203; the voltage divider submodule 2011 is connected in parallel with the first resistor.

[0026] The first resistor R1 is connected in series with the temperature sensor 203 as a voltage-dividing resistor, and plays a role in dividing the voltage for the temperature sensor 203 in the loop of the first power supply V1-first resistor R1-temperature sensor 203. At the same time, the embodiment of the present application also sets at least one voltage-dividing submodule 2011 in parallel with the first resistor R1. It can be imagined that the number of voltage-dividing submodules 2011 can be set manually, and there is no specific limitation. The resistance value of the voltage-dividing module 201 can be adjusted by setting the number of voltage-dividing submodules connected to the circuit.

[0027] In some examples, a switch device may be provided in each voltage-dividing submodule to control whether the voltage-dividing submodule is connected to the circuit, and the connection of the voltage-dividing submodule is controlled by the switch device, so that the resistance value of the voltage-dividing module 201 can be changed so that it can correspond to the resistance value of the temperature sensor 203. Specifically, when the resistance value of the temperature sensor 203 becomes smaller, the switch devices in the multiple voltage-dividing submodules are controlled to be closed accordingly, and when the resistance value of the temperature sensor 203 becomes larger, the switch devices in the multiple voltage-dividing submodules are controlled to be disconnected.

[0028] By setting the first resistor R1 in the voltage divider module, the temperature sensor 203 can be stably divided. At the same time, at least one voltage divider sub-module is set to adjust the resistance value of the voltage divider module 201, so that the resistance value of the voltage divider module 201 is variable, which is beneficial for the voltage value at the pin of the main control chip to meet the temperature detection accuracy of the main control chip.

[0029] In some embodiments, Figure 3 The voltage divider module includes a first switch S1 and a second resistor R2; the first end of the first switch S1 is connected to the positive electrode of the first power supply V1, the second end of the first switch S1 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is connected to the first end of the temperature sensor.

[0030] The voltage divider submodule may include a first switch S1 and a second resistor R2 connected in series, and whether the second resistor R2 is connected to the circuit is adjusted by closing or opening the first switch S1, thereby adjusting the resistance value of the voltage divider module 201. For example, when the first switch S1 is closed, the voltage divider module 201 includes the first resistor R1 and the second resistor R2 connected in parallel, and the resistance of the voltage divider module is reduced compared to the case where only the first resistor R1 is connected to the circuit, the voltage divided by the voltage divider module 201 is reduced, and the voltage at the pin of the main control chip 204 is increased.

[0031] In some examples, the voltage divider resistors R1 and R2 in the voltage divider module can have different levels of resistance values, for example, the resistance value of R1 is about 100Ω, and the resistance value of R2 is about 1000Ω. Setting different levels of resistance values ​​can make the resistance value of the voltage divider module 201 and the resistance value of the temperature sensor 203 at the same level. For example, when the resistance value of the temperature sensor 203 is at the hundred ohm level, the resistance value of the voltage divider module 201 is also at the hundred ohm level.

[0032] The embodiment of the present application sets a first switch S1 and a second resistor R2 in the voltage divider submodule, so that the voltage divider submodule can set whether the second resistor R2 is connected to power by closing and opening the first switch S1, which is conducive to flexible adjustment of the voltage value at the pin of the main control chip to meet the detection accuracy of the main control chip for temperature.

[0033] In some embodiments, Figure 3 The amplification module 202 includes a fourth resistor R4, a fifth resistor R5 and an amplifier A; the first end of the fourth resistor R4 is connected to the positive electrode of the second power supply V2, and the second end of the fourth resistor R4 is connected to the inverting input end of the amplifier A; the non-inverting input end of the amplifier A is connected to the output end of the voltage divider module 201, and the output end of the amplifier A is respectively connected to the main control chip 204 and the first end of the fifth resistor R5, and the second end of the fifth resistor R5 is connected to the inverting input end of the amplifier.

[0034] An amplifier A may be provided in the amplification module 202, and the amplifier A may amplify the voltage at the pin of the main control chip 204. The second power supply V2 and the fourth resistor R4 are connected to the inverting input terminal of the amplifier, and the fifth resistor R5 is connected to the output terminal of the amplifier A. The fifth resistor R5 serves as a feedback resistor, and together with the fourth resistor R4 and the amplifier A, constitutes the amplification module 202 with an amplification function. It is conceivable that the amplification factor of the amplification module 202 is approximately the ratio of the resistance value of R5 to the resistance value of R4.

[0035] In the embodiment of the present application, the fourth resistor R4, the fifth resistor R5 and the amplifier A are set in the amplification module to amplify the voltage at the pin of the main control chip 204, so that the voltage value at the pin of the main control chip can meet the temperature detection accuracy of the main control chip, thereby improving the temperature detection accuracy of the temperature detection circuit.

[0036] In some embodiments, Figure 3 The amplification module 202 further includes a sixth resistor R6; a first end of the sixth resistor R6 is connected to the positive electrode of the second power supply, and a second end of the sixth resistor is connected to the first end of the fourth resistor R4.

[0037] A sixth resistor R6 is connected in series between the second power supply V2 and the fourth resistor R4. The sixth resistor R6 can play a voltage dividing role in the loop of the second power supply V2-sixth resistor R6-fourth resistor R4, and can also protect the amplifier A.

[0038] In some embodiments, Figure 3 The amplification module further includes a second switch S2; a first end of the second switch S2 is connected to the positive electrode of the second power supply V2, and a second end of the second switch S2 is connected to the first end of the sixth resistor R6.

[0039] A second switch S2 is connected in series between the second power supply V2 and the sixth resistor R6, and whether the amplifier A is connected to the circuit can be controlled by opening and closing the second switch S2. For example, when the second switch S2 is closed, the amplifier A is connected to the circuit, and the amplifier A can amplify the voltage at the pin of the main control chip 204; when the second switch is opened, the amplifier cannot amplify the voltage at the pin of the main control chip 204. It can be imagined that when the resistance value of the temperature sensor 203 is large, the second switch S2 can be closed to allow the amplifier A to amplify the voltage at the pin of the main control chip 204; when the resistance value of the temperature sensor 203 is small, the second switch S2 can be opened to control the amplifier A not to be connected to the circuit.

[0040] By setting a second switch S2 in the amplification module of the temperature detection circuit to control whether the amplifier A is connected to the circuit, it is possible to flexibly control whether the amplifier amplifies the voltage at the pin of the main control chip 204, so that the voltage at the pin of the main control chip 204 can meet the temperature detection accuracy of the main control chip 204, thereby improving the temperature detection accuracy of the temperature detection circuit.

[0041] In some embodiments, Figure 3 The amplifying module 202 further includes a control module 2021, an input end of the control module 2021 is connected to the second end of the sixth resistor R6, and an output end of the control module 2021 is connected to the reference voltage end GND.

[0042] A control module 2021 is also provided in the amplifying module 202, and a complete loop of the second power supply V2-sixth resistor R6-control module 2021-reference voltage terminal GND is formed in the amplifying module 202. The control module 2021 can control the voltage value at the inverting input pin of the amplifier A, thereby controlling the amplification factor of the amplifier A.

[0043] In this embodiment, by setting the control module 2021 to control the amplification factor of the amplifier A, the voltage at the pin of the main control chip 204 can be flexibly amplified so that it can meet the temperature detection accuracy of the main control chip 204 and improve the temperature detection accuracy of the temperature detection circuit.

[0044] In some examples, a variable resistance resistor may be provided in the control module 2021 , and the voltage at the inverting input pin of the amplifier A may be flexibly controlled by changing the resistance of the resistor in the control module 2021 .

[0045] In some embodiments, Figure 3 The control module 2021 includes a seventh resistor R7 and a third switch S3; the first end of the seventh resistor R7 is connected to the second end of the sixth resistor R6, and the second end of the seventh resistor R7 is connected to the reference voltage terminal GND; the third switch S3 is connected in parallel with the seventh resistor R7.

[0046] The seventh resistor R7 and the third switch S3 connected in parallel therewith are provided in the control module 2021. By setting the closing and opening of the third switch S3, whether the seventh resistor R7 is short-circuited can be controlled, thereby adjusting the amplification factor of the amplifier A. It can be imagined that when the third switch S3 is closed, the seventh resistor R7 is short-circuited, which is equivalent to the seventh resistor R7 not being connected to the circuit, and the amplification factor of the amplifier A is approximately the resistance value of R5 / the resistance value of R4; when the third switch S3 is disconnected, the seventh resistor R7 is connected to the circuit, and the amplification factor of the amplifier A is approximately the resistance value of R5 / (the resistance value of R4+the resistance value of R7).

[0047] By setting the seventh resistor R7 and the third switch S3 in parallel in the control module 2021, the amplification factor of the amplifier A can be flexibly controlled by controlling the opening and closing of the third switch S3, so that the voltage at the pin of the main control chip 204 can meet the temperature detection accuracy of the main control chip 204, thereby improving the temperature detection accuracy of the temperature detection circuit.

[0048] In some embodiments, Figure 3 The amplification module 202 also includes an eighth resistor R8; a first end of the eighth resistor R8 is connected to the output end of the voltage divider module 201, and a second end of the eighth resistor R8 is connected to the non-inverting input end of the amplifier A.

[0049] An eighth resistor R8 is directly connected in series between the output end of the voltage divider module 201 and the non-inverting input end of the amplifier A, so as to divide the voltage at the non-inverting input pin of the amplifier A and protect the amplifier A.

[0050] In some embodiments, Figure 3 The temperature detection circuit also includes a ninth resistor R9; the ninth resistor R9 is connected in parallel with the temperature sensor 203.

[0051] The embodiment of the present application further provides a ninth resistor R9 connected in parallel with the temperature sensor, which can reduce the voltage across the temperature sensor in the loop of the first power supply V1 - voltage dividing module 201 - temperature sensor 203 .

[0052] In some examples, a switch device can be connected in series with the ninth resistor R9. When the resistance value of the temperature sensor is large, the switch is closed to connect the ninth resistor R9 in parallel with the temperature sensor, thereby reducing the voltage across the temperature sensor; when the resistance value of the temperature sensor 203 is small, the switch is disconnected to prevent the ninth resistor R9 from being connected in parallel with the temperature sensor 203.

[0053] By setting the ninth resistor R9 in parallel with the temperature sensor 203, the voltage across the temperature sensor 203 is further reduced, so that the voltage value at the pin of the main control chip 204 can meet the temperature detection accuracy of the main control chip 204, thereby improving the temperature detection accuracy of the temperature detection circuit.

[0054] In some examples, such as Figure 3 In the temperature detection circuit shown, the first switch S1, the second switch S2 and the third switch S3 can be selected from MOS tubes. Specifically, the first switch S1 and the second switch S2 can be selected from P-type MOS tubes, and the third switch S3 can be selected from N-type MOS tubes.

[0055] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present application (including the claims) is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0056] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0057] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or devices based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0058] The above reference is according to the method of the embodiment of the present application, the flow chart of the device (device) and the computer program product and / or the block diagram described various aspects of the present application.It should be understood that each square box in the flow chart and / or the block diagram and the combination of each square box in the flow chart and / or the block diagram can be realized by computer program instructions.These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the realization of the function / action specified in one or more square boxes of the flow chart and / or the block diagram.Such a processor can be but is not limited to a general-purpose processor, a special-purpose processor, a special application processor or a field programmable logic circuit.It can also be understood that each square box in the block diagram and / or the flow chart and the combination of the square boxes in the block diagram and / or the flow chart can also be realized by the dedicated hardware that performs the specified function or action, or can be realized by the combination of dedicated hardware and computer instructions.

[0059] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the above-described devices, modules and units can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application.

Claims

1. A temperature detection circuit, characterized in that: include: Voltage divider module, amplifier module, temperature sensor and main control chip; The input end of the voltage divider module is connected to the positive electrode of the first power supply, the output end of the voltage divider module is connected to the first end of the temperature sensor, and the second end of the temperature sensor is connected to the reference voltage end; The input end of the amplification module is connected to the output end of the voltage divider module, and the output end of the amplification module is connected to the main control chip; The voltage dividing module comprises a first resistor and at least one voltage dividing submodule; The first end of the first resistor is connected to the positive electrode of the first power supply, and the second end of the first resistor is connected to the first end of the temperature sensor; The voltage dividing submodule is connected in parallel with the first resistor; The voltage dividing submodule includes a first switch and a second resistor; The first end of the first switch is connected to the positive electrode of the first power supply, the second end of the first switch is connected to the first end of the second resistor, and the second end of the second resistor is connected to the first end of the temperature sensor.

2. The temperature detection circuit according to claim 1, characterized in that: The amplification module includes a fourth resistor, a fifth resistor and an amplifier; A first end of the fourth resistor is connected to the positive electrode of the second power supply, and a second end of the fourth resistor is connected to the inverting input terminal of the amplifier; The non-inverting input terminal of the amplifier is connected to the output terminal of the voltage divider module, the output terminal of the amplifier is respectively connected to the main control chip and the first end of the fifth resistor, and the second end of the fifth resistor is connected to the inverting input terminal of the amplifier.

3. The temperature detection circuit according to claim 2, characterized in that: The amplification module further includes a sixth resistor; A first end of the sixth resistor is connected to the positive electrode of the second power supply, and a second end of the sixth resistor is connected to the first end of the fourth resistor.

4. The temperature detection circuit according to claim 3, characterized in that: The amplification module further includes a second switch; a first end of the second switch is connected to the positive electrode of the second power supply, and a second end of the second switch is connected to the first end of the sixth resistor.

5. The temperature detection circuit according to claim 3, characterized in that: The amplification module further includes a control module, an input end of the control module is connected to the second end of the sixth resistor, and an output end of the control module is connected to a reference voltage end.

6. The temperature detection circuit according to claim 5, characterized in that: The control module includes a seventh resistor and a third switch; The first end of the seventh resistor is connected to the second end of the sixth resistor, and the second end of the seventh resistor is connected to the reference voltage end; The third switch is connected in parallel with the seventh resistor.

7. The temperature detection circuit according to claim 2, characterized in that: The amplification module further includes an eighth resistor; A first end of the eighth resistor is connected to the output end of the voltage divider module, and a second end of the eighth resistor is connected to the non-inverting input end of the amplifier.

8. The temperature detection circuit according to claim 1, characterized in that: Also included is a ninth resistor; The ninth resistor is connected in parallel with the temperature sensor.

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