Integrated temperature sensor

Abstract

The invention relates to an integrated temperature sensor which is powered by an external power supply, and the integrated temperature sensor comprises a first power supply pin and a second power supply pin, and the first power supply pin and the second power supply pin are connected to the positive electrode and the negative electrode of the external power supply respectively; the resistance value of the thermistor changes along with the change of the ambient temperature under the excitation of the external power supply; the voltage dividing element and the thermistor are connected in series between the first power supply pin and the second power supply pin; and a first output pin and a second output pin, wherein the first output pin and the second output pin are respectively connected to two ends of the thermistor.

Description

Technical Field

[0001] The present invention relates to the field of temperature sensing, and more particularly, to an integrated temperature sensor. Background Art

[0002] Temperature sensors are widely used in vehicles. For example, temperature sensors are required in the engine cooling system of a vehicle to monitor the engine temperature. The engine temperature is a key parameter necessary for the normal operation of the engine. Generally, the temperature sensor is installed in the engine or the cooling system to monitor the temperature of the coolant in real time. By monitoring the engine temperature, the vehicle system can adjust the operating speed of the cooling fan or activate the auxiliary cooling system to ensure that the engine remains within an appropriate operating temperature range, thereby improving fuel efficiency and extending the service life of the engine.

[0003] In addition, temperature sensors can also be applied to the air conditioning system of a vehicle. These temperature sensors are usually installed inside the vehicle to monitor the ambient temperature in the driver's cabin and the passenger cabin. According to the collected temperature information, the vehicle air conditioning system can accordingly adjust the fan speed and cooling effect to ensure that the interior of the vehicle always maintains a comfortable temperature, which helps to improve the comfort of the driver and passengers.

[0004] Conventional temperature sensor products on the market require different pull-up resistors to be configured for temperature sensing elements in different temperature ranges. This not only increases the complexity of circuit design but also limits the application scenarios of the sensor. In particular, customers need to match the pull-up resistors themselves when using relevant temperature sensor products, which seriously affects the customer experience.

[0005] Furthermore, for conventional temperature sensor products, the vehicle ECU needs to collect signals from the temperature sensor at regular intervals, and a large amount of calculations are involved between collecting the signals and finally determining the temperature value, which increases the computing load of the ECU. Summary of the Invention

[0006] The present invention aims to solve the above-mentioned defects existing in existing temperature sensors and provides an integrated temperature sensor that can simplify circuit design, improve the application flexibility of the sensor, and reduce the computing load of the ECU.

[0007] An exemplary embodiment of the present invention provides an integrated temperature sensor that is powered by an external power supply. Among them, the integrated temperature sensor includes:

[0008] A first power supply pin and a second power supply pin, the first power supply pin and the second power supply pin are respectively connected to the positive and negative poles of the external power supply;

[0009] A thermistor, the resistance value of which changes with the change of the ambient temperature under the excitation of the external power supply;

[0010] A voltage dividing element, which is connected in series with the thermistor between the first power supply pin and the second power supply pin; and

[0011] A first output pin and a second output pin, which are respectively connected to both ends of the thermistor.

[0012] According to an optional embodiment, a processing circuit is integrated in the integrated temperature sensor, and the processing circuit is configured to collect the voltage values at both ends of the first output pin and the second output pin at every predetermined time interval, and calculate the ambient temperature around the thermistor based on the collected voltage values.

[0013] According to an optional embodiment, the processing circuit is further configured to perform an averaging calculation on a predetermined number of continuously obtained ambient temperatures, and determine the average result as the detected temperature of the integrated temperature sensor.

[0014] According to an optional embodiment, the processing circuit is further configured to provide the detected temperature to the electronic control unit of the vehicle to control corresponding vehicle functions.

[0015] According to an optional embodiment, the electronic control unit is selected from the group consisting of an engine control unit of the vehicle, a battery management unit, an air conditioning unit, and a transmission monitoring unit.

[0016] According to an optional embodiment, the thermistor is a negative temperature coefficient thermistor.

[0017] According to an optional embodiment, the voltage dividing element is a pull-up resistor.

[0018] According to an optional embodiment, the thermistor, the voltage dividing element, and the processing circuit are arranged on the same PCB board.

[0019] According to an optional embodiment, the integrated temperature sensor further includes a housing for encapsulating the PCB board.

[0020] Compared with traditional temperature sensors, the present invention realizes the integration and one-stop development of temperature sensors. In addition to the NTC element, a pull-up resistor and even a processor are integrated in the integrated temperature sensor, which enables customers to avoid separately matching a pull-up resistor for each sensor product, saving the workload of customers and enhancing the product competitiveness. Additionally, the integrated temperature sensor according to the present invention also optimizes the calculation process of the sensor temperature, thereby saving the memory of the vehicle ECU. Moreover, this integrated design scheme also saves the total package size of the temperature sensor and helps simplify the design of the external sampling circuit, making the entire temperature measurement system easier to integrate and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] By incorporating the accompanying drawings herein and the following detailed description together with the specific embodiments used to illustrate certain principles of the present invention, other features and advantages of the method of the present invention will become clear or will be more specifically illustrated. Figure 1

[0022] Figure 1 FIG. shows a simplified circuit diagram of a conventional temperature sensor.

[0023] Figure 2 FIG. shows a simplified circuit diagram of an integrated temperature sensor according to an exemplary embodiment of the present invention.

[0024] Figure 3 FIG. shows a schematic diagram of the external package of an integrated temperature sensor according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The integrated temperature sensor according to the present invention will be described below with reference to the drawings and by way of examples. In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention to those skilled in the relevant art. However, it is obvious to those skilled in the relevant art that some of these specific details may not be required for the implementation of the present invention. On the contrary, the present invention can be implemented by considering any combination of the following features and elements, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments and advantages are for illustrative purposes only and should not be regarded as elements or limitations of the claims.

[0026] Figure 1 ​A simplified circuit diagram of a conventional temperature sensor is shown. Among them, the NTC (negative temperature coefficient) thermistor element is the core of the entire sensor, and its working principle is based on the thermoelectric effect. When the NTC temperature sensor is exposed to the surrounding environment, the temperature change of the surrounding environment will cause the electron activity level in the NTC semiconductor element to change, thereby affecting its resistance value. For example, as the ambient temperature increases, the carrier density in the semiconductor increases, which will cause the NTC resistance value to decrease. Due to this characteristic of NTC, the ambient temperature around the sensor can be monitored by observing the voltage / resistance value changes of the NTC element.

[0027] In a conventional temperature sensor, the NTC is directly connected to an external sampling circuit (eg, a sampling pin of an ECU) through output pins P1 and P2.

[0028] Since the resistance value of the NTC changes with temperature, in order to convert the signal of the NTC into a temperature value, a pull-up resistor needs to be connected in series with it. The pull-up resistor creates a voltage divider circuit so that the relative change in the resistance value of the NTC resistor and the pull-up resistor can be converted into a measurable voltage change.

[0029] Typically, NTC thermistors with different temperature ranges need to be matched with pull-up resistors of different resistance values ​​in order to maintain the appropriate sensitivity of the circuit over the entire temperature range. This not only increases the complexity of circuit design, but also limits the application scenarios of the sensor.

[0030] In order to realize the integration and one-stop development of temperature sensors, the present invention proposes to build a pull-up resistor into the temperature sensor and design a new calculation method (voltage-temperature relationship function) accordingly. When customers use the sensor product, they only need to power the sensor and collect the voltage signal at both ends of the sensor to obtain the desired temperature sampling result, which saves the workload of customers and improves the competitiveness of the product. In addition, the integrated temperature sensor of the present invention can also save the memory of the ECU used to receive and process the sensor signal.

[0031] Figure 2 FIG. 1 shows a simplified circuit diagram of an integrated temperature sensor according to an exemplary embodiment of the present invention. The integrated temperature sensor can be powered by an external power supply Uin. Figure 2 As shown in the figure, the core component of this temperature sensor is also a thermistor. Figure 2 The example is a negative temperature coefficient thermistor (NTC for short). Under the stimulation of an external power source, the resistance of the thermistor changes with the change of the surrounding temperature.

[0032] The integrated temperature sensor may include a total of four pins PIN1 to PIN4. Among them, PIN1 and PIN2 are power supply pins, which are respectively connected to the positive and negative poles of the external power supply Uin. PIN3 and PIN4 are output pins, which are respectively led out from both ends of the NTC.

[0033] The special feature of this integrated temperature sensor is that it also integrates a voltage-dividing element Rs. The voltage-dividing element Rs and the NTC are connected in series between the first power supply pin PIN1 and the second power supply pin PIN2. Figure 2 In the example of, the voltage-dividing element Rs is a pull-up resistor, which is connected between the positive pole of the external power supply Uin and one end of the NTC, and the other end of the NTC is connected to the negative pole of the external power supply Uin.

[0034] Based on the voltage division principle of the series circuit, the following derivation formula can be obtained:

[0035]

[0036] Among them, Uout is the sampling voltage across the thermistor NTC, Rs is the resistance value of the pull-up resistor (for example, it is 1000 ohms), and R NTC is the derived current resistance value of the NTC. Based on this resistance value R NTC the ambient temperature around the NTC can be determined using a pre-determined look-up table.

[0037] According to an optional example, a processing circuit may also be integrated in this temperature sensor. The processing circuit is configured to collect the voltage value Uout across the first output pin PIN3 and the second output pin PIN4 at every predetermined time interval (for example, 100 s), and estimate the ambient temperature T around the thermistor NTC based on the collected voltage value.

[0038] Perform an average calculation on the continuously obtained predetermined number (for example, five times) of ambient temperatures, and determine the average result as the detection temperature T of this integrated temperature sensor. The detection temperature T can be provided to the electronic control unit ECU of the vehicle to control the corresponding vehicle functions. For example, the ECU can be selected from the group including the engine control unit, battery management unit, air conditioning unit, and transmission monitoring unit of the vehicle.

[0039] It can be understood that the above-described thermistor NTC, voltage-dividing element Rs, and processing circuit can be arranged on the same PCB board. In addition, this integrated temperature sensor may also include a housing for encapsulating the PCB board. Figure 3 Fig. shows a schematic diagram of the external package of the integrated temperature sensor according to an exemplary embodiment of the present invention.

[0040] Compared with traditional temperature sensors, the present invention realizes the integration and one-stop development of temperature sensors. In addition to the NTC element, a pull-up resistor and even a processor are integrated in the integrated temperature sensor, which enables customers to avoid separately matching pull-up resistors for each sensor product, saving the workload of customers and improving the product competitiveness. Additionally, the integrated temperature sensor according to the present invention also optimizes the calculation process of the sensor temperature, thereby saving the memory of the vehicle ECU. Moreover, this integrated design scheme also saves the total package size of the temperature sensor and helps to simplify the design of the external sampling circuit, making the entire temperature measurement system easier to integrate and use.

[0041] Compared with traditional temperature sensors, the present invention realizes the integration and one-stop development of temperature sensors. In addition to including the NTC element, the integrated temperature sensor also integrates a pull-up resistor and a processor, eliminating the need for customers to separately match pull-up resistors for each sensor product, thus reducing the workload of customers and improving the product competitiveness. Furthermore, the integrated temperature sensor of the present invention effectively saves the memory of the vehicle ECU by optimizing the temperature calculation process. Adopting this integrated design scheme also reduces the total package cost of the temperature sensor and helps to simplify the design complexity of the overall sensing and processing circuit.

[0042] Those skilled in the art can understand that in the present invention, terms such as "comprising" and "including" indicate that in addition to the steps directly and clearly described in the specification and claims, the technical solution of the present application does not exclude the situation of having other steps not directly or clearly described.

[0043] Although the present invention has been disclosed above with preferred embodiments, the present invention is not limited thereto. Any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. An integrated temperature sensor, which is powered by an external power supply, characterized in that, The integrated temperature sensor includes: A first power supply pin and a second power supply pin, where the first power supply pin and the second power supply pin are respectively connected to the positive and negative poles of the external power supply; A thermistor, whose resistance value changes with the change of the ambient temperature under the excitation of the external power supply; A voltage dividing element, which is connected in series with the thermistor between the first power supply pin and the second power supply pin; and A first output pin and a second output pin, where the first output pin and the second output pin are respectively connected to both ends of the thermistor.

2. The integrated temperature sensor according to claim 1, characterized in that, A processing circuit is integrated in the integrated temperature sensor. The processing circuit is configured to collect the voltage values at both ends of the first output pin and the second output pin at every predetermined time interval, and calculate the ambient temperature around the thermistor based on the collected voltage values.

3. The integrated temperature sensor according to claim 2, characterized in that, The processing circuit is further configured to calculate the average value of a predetermined number of continuously obtained ambient temperatures, and determine the average result as the detected temperature of the integrated temperature sensor.

4. The integrated temperature sensor according to claim 3, characterized in that, The processing circuit is further configured to provide the detected temperature to the electronic control unit of the vehicle to control the corresponding vehicle functions.

5. The integrated temperature sensor according to claim 4, characterized in that, The electronic control unit is selected from the group including the engine control unit, battery management unit, air conditioning unit, and transmission monitoring unit of the vehicle.

6. The integrated temperature sensor according to any one of claims 1 to 5, characterized in that, The thermistor is a negative temperature coefficient thermistor.

7. The integrated temperature sensor according to any one of claims 1 to 5, characterized in that, The voltage dividing element is a pull-up resistor.

8. The integrated temperature sensor according to any one of claims 2 to 5, characterized in that, The thermistor, the voltage dividing element, and the processing circuit are arranged on the same PCB board.

9. The integrated temperature sensor according to claim 8, characterized in that, The integrated temperature sensor further includes a housing for encapsulating the PCB board.

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