Temperature measuring device, temperature measuring method and temperature measuring system

Abstract

The invention provides a temperature measuring device, a temperature measuring method and a temperature measuring system. The temperature measuring device comprises a temperature measuring circuit and a control circuit, the temperature measuring circuit comprises a divider resistor and a thermistor, the first end of the divider resistor is used for receiving power supply voltage, and the second end of the divider resistor and the first end of the thermistor are coupled to a temperature measuring node; the control circuit comprises an open-drain structure and a sampling module, the output end of the open-drain structure is coupled to the second end of the thermistor, and the sampling module is coupled to the temperature measurement node. When the temperature measurement circuit needs to measure the temperature, the output end of the open-drain structure pulls down the second end of the thermistor to the ground, so that the temperature measurement circuit is in a conducting state. When the temperature measurement circuit does not need to measure temperature, the output end of the open-drain structure is in a high-resistance state to disconnect the second end of the thermistor, so that the temperature measurement circuit is in an open-circuit state; the sampling module collects the voltage of the thermistor so as to obtain the to-be-measured temperature. According to the invention, the power consumption of the temperature measuring device (such as an NTC temperature measuring circuit) can be effectively reduced while the temperature measuring precision is ensured.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a temperature measuring device, a temperature measuring method and a temperature measuring system. Background Art

[0002] In the field of automotive electronic controllers, automotive grade certification has become an important standard to ensure the stable operation of various components and the overall reliability of the system. This certification requires that automotive electronic controllers can maintain the stability and reliability of their performance under various harsh conditions, such as extreme temperature, vibration, electromagnetic interference, etc. Therefore, it is particularly important to monitor the temperature of the controller cavity and circuit board in real time, which can not only prevent damage to components caused by overheating, but also is a key link in meeting automotive grade certification.

[0003] At present, in the automotive industry, temperature detection is mostly achieved through thermistors. This detection method usually connects a thermistor in series with a pull-up or pull-down resistor. By measuring the voltage divider value at both ends of the thermistor, the current temperature can be indirectly calculated. However, although this method is simple and effective, with the continuous advancement of automotive electronic technology and increasingly stringent environmental regulations, higher requirements are placed on the low-power design of automotive electronic controllers. The traditional NTC temperature measurement method requires continuous application of voltage to the thermistor, which is particularly disadvantageous in the context of the automotive industry that increasingly emphasizes energy efficiency and environmental protection, because it runs counter to the concept of low-power design of the controller and can no longer meet the high-efficiency and low-energy consumption requirements of modern automotive electronics.

[0004] Therefore, how to further reduce the power consumption of the NTC temperature measurement circuit while ensuring the temperature measurement accuracy has become one of the technical problems that need to be solved urgently in the current field of automotive electronic controller design.

[0005] It should be noted that the information disclosed in the background technology section of the invention is only intended to deepen the understanding of the general background technology of the invention, and should not be regarded as an admission or suggestion in any form that the information constitutes prior art already known to those skilled in the art. Summary of the invention

[0006] The object of the present invention is to provide a temperature measuring device, a temperature measuring method and a temperature measuring system, so as to effectively reduce the power consumption of the temperature measuring device (for example, an NTC temperature measuring circuit) while ensuring the temperature measurement accuracy.

[0007] In order to achieve the above-mentioned object, the present invention is implemented by the following technical scheme: a temperature measuring device, the temperature measuring device includes a temperature measuring circuit and a control circuit, the temperature measuring circuit includes a voltage dividing resistor and a thermistor, the first end of the voltage dividing resistor is used to receive a power supply voltage, the second end of the voltage dividing resistor and the first end of the thermistor are coupled to a temperature measuring node, the control circuit includes an open drain structure and a sampling module, the output end of the open drain structure is coupled to the second end of the thermistor, and the sampling module is coupled to the temperature measuring node;

[0008] The open drain structure is configured such that when the temperature measuring circuit is required to measure temperature, the output end of the open drain structure pulls the second end of the thermistor down to the ground so that the temperature measuring circuit is in a conducting state; when the temperature measuring circuit is not required to measure temperature, the output end of the open drain structure is in a high impedance state to disconnect the second end of the thermistor, thereby putting the temperature measuring circuit in an open circuit state;

[0009] The sampling module is configured to collect the voltage of the thermistor to obtain the temperature to be measured.

[0010] Optionally, the open-drain structure includes an interface of a configurable open-drain output of a microcontroller;

[0011] The interface with configurable open-drain output is configured to pull the second end of the thermistor down to ground when the temperature measurement circuit is required to measure temperature so that the temperature measurement circuit is in an on state; when the temperature measurement circuit is not required to measure temperature, the output end of the open-drain structure is in a high-impedance state.

[0012] Optionally, the sampling module includes an analog-to-digital converter interface of the microcontroller.

[0013] Optionally, the open-drain structure includes a MOS tube, a first end of the MOS tube is coupled to a second end of the thermistor, a second end of the MOS tube is coupled to ground, and a control end of the MOS tube is used to receive a temperature measurement control signal;

[0014] The temperature measurement control signal is configured to turn on the MOS tube when the temperature measurement circuit is required to measure the temperature, and to turn off the MOS tube when the temperature measurement circuit is not required to measure the temperature.

[0015] Optionally, the sampling module includes an analog-to-digital converter.

[0016] Optionally, the thermistor includes a positive temperature coefficient thermistor or a negative temperature coefficient thermistor.

[0017] Optionally, the duty cycle of the temperature measurement circuit is required to be greater than or equal to 25% and less than or equal to 75%.

[0018] In order to achieve the above object, the present invention further provides a temperature measurement method for controlling any of the above-mentioned temperature measurement devices, the temperature measurement method comprising:

[0019] When the temperature measurement circuit is required to measure temperature, the output end of the open-drain structure is controlled to pull the second end of the thermistor down to the ground, so that the temperature measurement circuit is in a conducting state; and the voltage of the thermistor is collected through the sampling module to obtain the temperature to be measured;

[0020] When the temperature measurement circuit is not needed to measure temperature, the output end of the open-drain structure is controlled to be in a high-impedance state to disconnect the second end of the thermistor, thereby putting the temperature measurement circuit in an open-circuit state.

[0021] In order to achieve the above object, the present invention further provides a temperature measurement system, which includes any of the temperature measurement devices described above.

[0022] Optionally, the temperature measurement system further includes a microcontroller, an analog-to-digital converter interface of the microcontroller is coupled to the temperature measurement node of the temperature measurement device, and a configurable open-drain output interface of the microcontroller is coupled to the second end of the thermistor.

[0023] Compared with the prior art, the temperature measuring device, temperature measuring method and temperature measuring system provided by the present invention have the following advantages:

[0024] The temperature measuring device provided by the present invention includes a temperature measuring circuit and a control circuit, wherein the temperature measuring circuit includes a voltage dividing resistor and a thermistor, wherein the first end of the voltage dividing resistor is used to receive a power supply voltage, and the second end of the voltage dividing resistor is coupled to a temperature measuring node with the first end of the thermistor, and the control circuit includes an open-drain structure and a sampling module, wherein the output end of the open-drain structure is coupled to the second end of the thermistor, and the sampling module is coupled to the temperature measuring node; the open-drain structure is configured such that when the temperature measuring circuit is required to measure the temperature, the output end of the open-drain structure pulls the second end of the thermistor down to the ground so that the temperature measuring circuit is in a conducting state; when the temperature measuring circuit is not required to measure the temperature, the output end of the open-drain structure is in a high-impedance state so as to disconnect the second end of the thermistor, thereby making the temperature measuring circuit in an open-circuit state; the sampling module is configured to collect the voltage of the thermistor to obtain the temperature to be measured. It can be seen that the temperature measuring device provided by the present invention has an open-drain structure that can make the temperature measuring circuit in a conducting state when the temperature measuring circuit is needed to measure the temperature, and make the temperature measuring circuit in an open-circuit state when the temperature measuring circuit is not needed to measure the temperature. With such a configuration, the present invention can collect temperature values ​​according to actual needs and realize the on-demand measurement function. While ensuring the temperature measurement accuracy, it can effectively reduce the power consumption of the temperature measurement circuit (for example, the NTC temperature measurement circuit); further, the logic of the present invention is simple and easy to implement.

[0025] Furthermore, in the temperature measuring device provided by the present invention, the open-drain structure includes an interface of a configurable open-drain output of a microcontroller; the interface of the configurable open-drain output is configured to pull the second end of the thermistor down to ground when the temperature measuring circuit is required to measure temperature so that the temperature measuring circuit is in a conducting state, and when the temperature measuring circuit is not required to measure temperature, the output end of the open-drain structure is in a high-impedance state. With such a configuration, the power consumption of the temperature measuring circuit (for example, the NTC temperature measuring circuit) can be effectively reduced by multiplexing the interface of the configurable open-drain output of the microcontroller without increasing any hardware cost.

[0026] Furthermore, in the temperature measuring device provided by the present invention, the sampling module includes the analog-to-digital converter interface of the microcontroller. With such a configuration, temperature measurement can be performed through the temperature measuring circuit by multiplexing the analog-to-digital converter interface of the microcontroller without increasing any hardware cost.

[0027] Since the temperature measurement method and temperature measurement system provided by the present invention belong to the same inventive concept as the temperature measurement device provided by the present invention, the temperature measurement method and temperature measurement system provided by the present invention at least have all the advantages of the temperature measurement device provided by the present invention. For details on the beneficial effects of the temperature measurement method and temperature measurement system provided by the present invention, please refer to the above description of the beneficial effects of the temperature measurement device provided by the present invention, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A structural block diagram of a temperature measuring device provided in Embodiment 1 of the present invention;

[0029] Figure 2 A schematic diagram of the structure of a specific example of the temperature measuring device provided in the first embodiment of the present invention;

[0030] Figure 3 A schematic diagram of the structure of another specific example of the temperature measuring device provided in the first embodiment of the present invention;

[0031] Figure 4 A schematic diagram showing a comparison of current waveforms of a temperature measuring circuit of a temperature measuring device provided by the present invention and a temperature measuring circuit in related art under a working mode with a duty cycle of 50%;

[0032] Figure 5 A schematic diagram of the overall flow of the temperature measurement method provided in the second embodiment of the present invention;

[0033] The reference numerals are as follows:

[0034] Temperature measurement circuit-100, voltage divider resistor-R1, thermistor-R2, power supply voltage-VDD, capacitor-C, microcontroller-MCU, configurable open-drain output interface-AP1, analog-to-digital converter interface-AP2;

[0035] Control circuit-200, open-drain structure-210, sampling module-220;

[0036] MOS tube-Q, analog-to-digital converter-ADC. DETAILED DESCRIPTION

[0037] The temperature measuring device, temperature measuring method and temperature measuring system proposed in the present invention are further described in detail below in conjunction with the accompanying drawings. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are in a very simplified form and all use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Any modification of the structure, change of the proportional relationship or adjustment of the size, in the case of the same or similar effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. The specific design features of the present invention disclosed herein include, for example, specific dimensions, directions, positions and shapes, which will be determined in part by the specific environment to be applied and used. And, in the embodiments described below, sometimes the same figure mark is used to represent the same part or part with the same function between different drawings, and its repeated description is omitted. In this specification, similar reference numerals and letters are used to refer to similar items, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures. In addition, if the method described herein includes a series of steps, the order of these steps presented herein is not necessarily the only order in which these steps can be performed, and some of the steps described may be omitted and / or some other steps not described herein may be added to the method.

[0038] 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 sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements. The singular forms "a", "an" and "the" include plural objects, the term "or" is generally used in a sense including "and / or", the term "several" is generally used in a sense including "at least one", and the term "at least two" is generally used in a sense including "two or more". In addition, the terms "first", "second" and "third" are used for descriptive purposes only and are not to be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features.

[0039] It should be understood that when an element is referred to as being "connected," "connected to," or "coupled to" another element, it can be directly connected to the other element, or there can be intervening elements. Conversely, when an element is referred to as being "directly connected" or "directly connected to" another element, there are no intervening elements.

[0040] In addition, unless otherwise stated or apparent from the context, as used herein, the term "about" is understood to be within the normal tolerance range in the art, such as within 2 standard deviations of the mean. "About" may be understood to be within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the value. Unless otherwise clear from the context, all numerical values ​​provided herein are modified by the term "about".

[0041] The core idea of ​​the present invention is to provide a temperature measuring device, a temperature measuring method and a temperature measuring system, so as to effectively reduce the power consumption of the temperature measuring device (for example, an NTC temperature measuring circuit) while ensuring the temperature measurement accuracy.

[0042] Embodiment 1

[0043] In order to realize the above idea, this embodiment provides a temperature measuring device. For example, see Figure 1 , Figure 1 The structure block diagram of the temperature measuring device provided by the present invention. Figure 1It can be seen that the temperature measuring device includes a temperature measuring circuit 100 and a control circuit 200. The temperature measuring circuit 100 includes a voltage dividing resistor R1 and a thermistor R2. The first end of the voltage dividing resistor R1 is used to receive the power supply voltage VDD. The second end of the voltage dividing resistor R1 and the first end of the thermistor R2 are coupled to a temperature measurement node. The control circuit 200 includes an open drain structure 210 and a sampling module 220. The output end of the open drain structure 210 is coupled to the second end of the thermistor R2. The sampling module 220 is coupled to the temperature measurement node. Furthermore, the open-drain structure 210 is configured such that when the temperature measurement circuit 100 is required to measure temperature, the output end of the open-drain structure 210 pulls the second end of the thermistor R2 down to the ground so that the temperature measurement circuit 100 is in an on state; when the temperature measurement circuit 100 is not required to measure temperature, the output end of the open-drain structure 210 is in a high-impedance state to disconnect the second end of the thermistor R2, thereby putting the temperature measurement circuit 100 in an open-circuit state; the sampling module 220 is configured to collect the voltage of the thermistor R2 to obtain the temperature to be measured.

[0044] It can be seen that the temperature measuring device provided by the present invention has an open-drain structure 210 that can make the temperature measuring circuit 100 in an on state when the temperature measuring circuit 100 needs to measure the temperature, and make the temperature measuring circuit 100 in an off state when the temperature measuring circuit 100 does not need to measure the temperature. With such a configuration, the present invention can collect temperature values ​​according to actual needs and realize the on-demand measurement function. While ensuring the temperature measurement accuracy, it can effectively reduce the power consumption of the temperature measuring circuit 100 (for example, the NTC temperature measurement circuit); further, the logic of the present invention is simple and easy to implement.

[0045] It should be noted that, according to the description herein, those skilled in the art should be able to understand that the core idea of ​​the present invention is that, according to the actual need for temperature measurement, when temperature measurement is required, the loop where the thermistor R2 is located is turned on so that the temperature measurement circuit 100 is in a conducting state, and when measurement is not required, the loop where the thermistor R2 is located is turned off so that the temperature measurement circuit 100 is in a disconnected state, so as to reduce current consumption. Figure 2 and Figure 3 Two different implementations of the control circuit 200 for the temperature measurement circuit 100 provided by the present invention are exemplified. Obviously, this is only an exemplification of a preferred implementation and not a limitation. It should be understood that the present invention does not impose too many limitations on the specific implementation of the open-drain structure 210 and the sampling module 220.

[0046] Preferably, in some of the exemplary embodiments, see Figure 2 , Figure 2The following is a schematic diagram of a specific example of the temperature measuring device provided by the present invention. Figure 2 It can be seen that the open-drain structure 210 includes an interface AP1 with a configurable open-drain output of the microcontroller MCU; the interface AP1 with a configurable open-drain output is configured to pull the second end of the thermistor R2 to the ground when the temperature measurement circuit 100 is required to measure the temperature so that the temperature measurement circuit 100 is in a conducting state, and when the temperature measurement circuit 100 is not required to measure the temperature, the output end of the open-drain structure 210 is in a high-impedance state.

[0047] In such a configuration, the temperature measurement device provided by the present invention, the open-drain structure 210 includes an interface AP1 of a microcontroller MCU that can be configured to have an open-drain output; the interface AP1 of the configurable open-drain output is configured to pull the second end of the thermistor R2 down to the ground when the temperature measurement circuit 100 is required to measure temperature so that the temperature measurement circuit 100 is in a conducting state, and when the temperature measurement circuit 100 is not required to measure temperature, the output end of the open-drain structure 210 is in a high-impedance state. In such a configuration, the power consumption of the temperature measurement circuit 100 (for example, an NTC temperature measurement circuit) can be effectively reduced by multiplexing the interface AP1 of the microcontroller MCU that can have an open-drain output, without increasing any hardware cost.

[0048] Preferably, in some exemplary embodiments, the sampling module 220 includes the analog-to-digital converter interface AP2 of the microcontroller MCU. With such configuration, the temperature measurement device provided by the present invention, wherein the sampling module 220 includes the analog-to-digital converter interface AP2 of the microcontroller MCU, is configured such that the temperature measurement circuit 100 can be used to measure the temperature by multiplexing the analog-to-digital converter interface AP2 of the microcontroller MCU without increasing any hardware cost.

[0049] For example, Figure 2As shown, taking a certain microcontroller MCU as an example, by using its 12-bit high-precision analog-to-digital converter interface AP2 as a sampling module 220 for data acquisition, and using its configurable open-drain output interface AP1 as an open-drain structure 210 to control the conduction state of the thermistor R2 of the temperature measurement circuit 100, the core idea of ​​"when the temperature needs to be measured, the loop where the thermistor R2 is located is turned on to make the temperature measurement circuit 100 in a conduction state, and when no measurement is required, the loop where the thermistor R2 is located is turned off to make the temperature measurement circuit 100 in a disconnected state" is realized. Specifically, the temperature (digital) output function and the open-drain structure are realized by configuring the relevant registers of the microcontroller MCU. In terms of register configuration, reasonable configuration can be performed according to the pin description of the microcontroller MCU to ensure the normal operation of the control circuit 200. Exemplarily, when the temperature value needs to be read, the metal oxide semiconductor field effect transistor (MOS tube) inside the (corresponding) interface AP1 with configurable open drain output is activated, and the output of the port is pulled down to the ground (GND). At this time, the microcontroller MCU can read the voltage divider value of the thermistor R2, thereby completing the acquisition of the analog signal. When temperature measurement is not required, the MOS tube of the interface AP1 with configurable open drain output will be turned off. Observed from the outside of the microcontroller MCU, the impedance of the interface AP1 with configurable open drain output is in a high impedance state (Hi-Z) at this time. This means that the resistance value of the voltage divider loop becomes extremely large, almost equivalent to the open circuit state, so the current consumption of the temperature measurement circuit 100 (i.e., the circuit composed of the voltage divider resistor R1 and the thermistor R2) is almost zero. As a result, not only the demand for on-demand measurement is met, but also the energy efficiency performance of the circuit can be significantly improved.

[0050] It should be noted that, as those skilled in the art can understand, when the analog-to-digital converter interface AP2 of the microcontroller MCU is used as the sampling module 220 and the configurable open-drain output interface AP1 of the microcontroller MCU is used as the open-drain structure 210 to implement the temperature measuring device of the present invention, the present invention does not impose too many restrictions on the specific model and use of the microcontroller MCU.

[0051] Preferably, in some other exemplary embodiments, see Figure 3 , Figure 3 The schematic diagram of the structure of another specific example of the temperature measuring device provided by the present invention. Figure 3It can be seen that the open-drain structure 210 includes a MOS tube Q, a first end of the MOS tube Q (such as the drain of a PMOS tube) is coupled to the second end of the thermistor R2, a second end of the MOS tube Q (such as the source of a PMOS tube) is coupled to ground, and a control end of the MOS tube Q is used to receive a temperature measurement control signal; the temperature measurement control signal is configured to turn on the MOS tube Q when the temperature measurement circuit 100 is required to measure temperature, and to turn off the MOS tube Q when the temperature measurement circuit 100 is not required to measure temperature. Thus, the MOS tube Q is used to implement the open-drain structure 210, which not only has a simple circuit structure and is easy to implement, but also is easy to obtain and inexpensive.

[0052] Preferably, please continue to see Figure 3 ,like Figure 3 As shown, the sampling module 220 includes an analog-to-digital converter ADC. Thus, the sampling module 220 is implemented by using the analog-to-digital converter ADC, and the circuit structure is simple and easy to implement. It should be noted that, as can be understood by those skilled in the art, the present invention does not impose too many restrictions on the acquisition accuracy of the analog-to-digital converter ADC, and when implementing the present invention, the analog-to-digital converter ADC of the corresponding accuracy can be reasonably selected according to actual needs.

[0053] Preferably, in some of the exemplary embodiments, please continue to refer to Figure 2 The thermistor R2 includes a positive temperature coefficient (PTC) thermistor or a negative temperature coefficient (NTC) thermistor.

[0054] Please continue to see Figure 2 ,like Figure 2 As shown, the temperature measuring device also includes a capacitor C, a first end of the capacitor C is coupled to the temperature measuring node, and a second end of the capacitor C is coupled to the second end of the thermistor R2, thereby further improving the stability and test accuracy of the temperature measuring device.

[0055] Preferably, in some exemplary embodiments, the resistance of the voltage-dividing resistor R1 is 10KΩ-30KΩ, and the typical impedance value of the thermistor R2 at 25° C. is 80KΩ-120KΩ. Preferably, the resistance of the voltage-dividing resistor R1 is 20KΩ, the typical impedance value of the thermistor R2 at 25° C. is 100KΩ, and the supply voltage VDD is 5V.

[0056] Preferably, in some exemplary embodiments, the duty cycle of the temperature measurement circuit is greater than or equal to 25% and less than or equal to 75%. Thus, by reasonably selecting the duty cycle of the temperature measurement circuit, power consumption and temperature measurement effect can be well balanced.

[0057] It should be noted that, as those skilled in the art can understand, the present invention does not impose too many restrictions on the specific value of the duty cycle of the temperature measurement circuit required for temperature measurement. When implementing the present invention, it should be reasonably selected according to actual needs. The smaller the duty cycle of the temperature measurement circuit required for temperature measurement, the lower the power consumption of the speed measurement circuit.

[0058] For example, see Figure 4 , Figure 4 The figure is a schematic diagram for comparing the current waveforms of the temperature measuring circuit of the temperature measuring device provided by the present invention and the temperature measuring circuit in the related art under the working mode with a duty cycle of 50%. Figure 4 In the embodiment, the resistance of the voltage divider resistor R1 is 20KΩ, the impedance of the thermistor R2 at 25°C is typically 100KΩ, and in the temperature measurement circuit in the related art, the measured current consumption is a constant 0.04mA. Assuming that the temperature to be measured remains unchanged and without considering the influence of temperature change on the impedance of the NTC resistor, the current consumption of the temperature measurement circuit in the related art is a constant value. By comparison, it can be seen that, using the temperature measurement device provided by the present invention, in the working mode with a duty cycle of 50%, the average current consumption of the temperature measurement circuit 100 is only half of that of the related art, which significantly reduces the power consumption of the temperature measurement circuit 100.

[0059] Embodiment 2

[0060] Based on the same inventive concept, this embodiment provides a temperature measurement method, which is used to control the temperature measurement device as described in any implementation method of the first embodiment. Figure 5 , Figure 5 The overall flow chart of the temperature measurement method provided in this embodiment is as follows. Figure 5 It can be seen that the temperature measurement method provided in this embodiment includes:

[0061] S100: When the temperature measurement circuit is required to measure temperature, the output end of the open-drain structure is controlled to pull the second end of the thermistor down to the ground, so that the temperature measurement circuit is in a conducting state; and the voltage of the thermistor is collected through the sampling module to obtain the temperature to be measured;

[0062] S200: When the temperature measurement circuit is not needed to measure temperature, the output end of the open-drain structure is controlled to be in a high-impedance state to disconnect the second end of the thermistor, thereby putting the temperature measurement circuit in an open-circuit state.

[0063] The temperature measurement method provided by the present invention can make the temperature measurement circuit be in a conducting state when the temperature measurement circuit is needed to measure the temperature, and make the temperature measurement circuit be in an open circuit state when the temperature measurement circuit is not needed to measure the temperature. It can be seen that the present invention realizes the on-demand measurement function, while ensuring the temperature measurement accuracy, it can effectively reduce the power consumption of the temperature measurement circuit (for example, the NTC temperature measurement circuit); further, the logic is simple and easy to implement.

[0064] Since the temperature measurement method provided by the present invention and the temperature measurement device provided by the present invention belong to the same inventive concept and have the same basic principles, the temperature measurement method provided by the present invention will not be described in detail herein. For more detailed contents of the temperature measurement method provided by the present invention, please refer to the relevant description of the temperature measurement device provided by the present invention above for adaptive understanding.

[0065] Embodiment 3

[0066] Based on the same inventive concept, this embodiment provides a temperature measurement system, which includes the temperature measurement device described herein. Therefore, the temperature measurement system provided by the present invention can effectively reduce the power consumption of the temperature measurement circuit 100 (eg, NTC temperature measurement circuit) while ensuring the temperature measurement accuracy.

[0067] For further information, see Figure 2 The temperature measurement system further includes a microcontroller MCU, an analog-to-digital converter interface AP2 of the microcontroller MCU is coupled to the temperature measurement node of the temperature measurement circuit 100, and an interface AP1 of the microcontroller MCU with a configurable open-drain output is coupled to the second end of the thermistor R2. Thus, by multiplexing the interface AP1 with a configurable open-drain output and the analog-to-digital converter interface AP2 of the microcontroller MCU, the power consumption of the temperature measurement circuit 100 (for example, an NTC temperature measurement circuit) can be effectively reduced without increasing any hardware cost.

[0068] Compared with the prior art, the temperature measuring device, temperature measuring method and temperature measuring system provided by the present invention have the following advantages:

[0069] (1) The temperature measuring device provided by the present invention has an open-drain structure that can make the temperature measuring circuit in a conducting state when the temperature measuring circuit is required to measure the temperature, and make the temperature measuring circuit in an open-circuit state when the temperature measuring circuit is not required to measure the temperature. With such a configuration, the present invention can collect temperature values ​​according to actual needs and realize the on-demand measurement function. While ensuring the temperature measurement accuracy, it can effectively reduce the power consumption of the temperature measuring circuit (for example, the NTC temperature measuring circuit); further, the present invention has simple logic and is easy to implement.

[0070] (2) In the temperature measuring device provided by the present invention, the open-drain structure includes an interface of a configurable open-drain output of a microcontroller; the interface of the configurable open-drain output is configured to pull the second end of the thermistor down to ground when the temperature measuring circuit is required to measure temperature so that the temperature measuring circuit is in a conducting state, and when the temperature measuring circuit is not required to measure temperature, the output end of the open-drain structure is in a high-impedance state. With such a configuration, the power consumption of the temperature measuring circuit (for example, the NTC temperature measuring circuit) can be effectively reduced by multiplexing the interface of the configurable open-drain output of the microcontroller without increasing any hardware cost.

[0071] (3) The temperature measuring device provided by the present invention has a sampling module including an analog-to-digital converter interface of the microcontroller. With such a configuration, the temperature can be measured through a temperature measuring circuit by multiplexing the analog-to-digital converter interface of the microcontroller without increasing any hardware cost.

[0072] In addition, the functional modules in the various embodiments of this document may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0073] The above description is only a description of the preferred embodiments of the temperature measuring device, temperature measuring method and temperature measuring system provided by the present invention, and is not intended to limit the scope of the present invention. Any changes and modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the present invention. Obviously, a person skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations fall within the scope of the present invention and its equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A temperature measuring device, characterized in that: The temperature measuring device comprises a temperature measuring circuit and a control circuit, wherein the temperature measuring circuit comprises a voltage-dividing resistor and a thermistor, wherein a first end of the voltage-dividing resistor is used to receive a power supply voltage, and a second end of the voltage-dividing resistor and a first end of the thermistor are coupled to a temperature measuring node, wherein the control circuit comprises an open-drain structure and a sampling module, wherein an output end of the open-drain structure is coupled to a second end of the thermistor, and the sampling module is coupled to the temperature measuring node; The open drain structure is configured such that when the temperature measurement circuit needs to measure temperature, the output end of the open drain structure pulls the second end of the thermistor down to the ground so that the temperature measurement circuit is in a conducting state; When the temperature measurement circuit is not needed to measure temperature, the output end of the open-drain structure is in a high-impedance state to disconnect the second end of the thermistor, thereby putting the temperature measurement circuit in an open-circuit state; The sampling module is configured to collect the voltage of the thermistor to obtain the temperature to be measured.

2. The temperature measuring device according to claim 1, characterized in that: The open-drain structure includes an interface for a configurable open-drain output of a microcontroller; The interface with configurable open-drain output is configured to pull the second end of the thermistor down to ground when the temperature measurement circuit is required to measure temperature so that the temperature measurement circuit is in an on state; when the temperature measurement circuit is not required to measure temperature, the output end of the open-drain structure is in a high-impedance state.

3. The temperature measuring device according to claim 2, characterized in that: The sampling module includes an analog-to-digital converter interface of the microcontroller.

4. The temperature measuring device according to claim 1, characterized in that: The open-drain structure includes a MOS tube, a first end of the MOS tube is coupled to the second end of the thermistor, the second end of the MOS tube is coupled to the ground, and a control end of the MOS tube is used to receive a temperature measurement control signal; The temperature measurement control signal is configured to turn on the MOS tube when the temperature measurement circuit is required to measure the temperature, and to turn off the MOS tube when the temperature measurement circuit is not required to measure the temperature.

5. The temperature measuring device according to claim 1, characterized in that: The sampling module includes an analog-to-digital converter.

6. The temperature measuring device according to claim 1, characterized in that: The thermistor includes a positive temperature coefficient thermistor or a negative temperature coefficient thermistor.

7. The temperature measuring device according to any one of claims 1 to 6, characterized in that: The temperature measurement circuit is required to have a temperature measurement duty cycle greater than or equal to 25% and less than or equal to 75%.

8. A temperature measurement method, characterized in that: Used to control the temperature measuring device according to any one of claims 1 to 7, the temperature measuring method comprising: When the temperature measurement circuit is required to measure temperature, the output end of the open-drain structure is controlled to pull the second end of the thermistor down to the ground, so that the temperature measurement circuit is in a conducting state; and the voltage of the thermistor is collected through the sampling module to obtain the temperature to be measured; When the temperature measurement circuit is not needed to measure temperature, the output end of the open-drain structure is controlled to be in a high-impedance state to disconnect the second end of the thermistor, thereby putting the temperature measurement circuit in an open-circuit state.

9. A temperature measurement system, characterized in that: The temperature measurement system comprises the temperature measurement device according to any one of claims 1 to 7.

10. The temperature measurement system according to claim 9, characterized in that: The temperature measurement system further includes a microcontroller, an analog-to-digital converter interface of the microcontroller is coupled to the temperature measurement node of the temperature measurement device, and a configurable open-drain output interface of the microcontroller is coupled to the second end of the thermistor.

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