Temperature detection circuit and device

Abstract

The application discloses a temperature detection circuit and device, comprising a reference current generation module, a temperature detection module, a mirror current output module and a detection voltage output module; the temperature detection module converts the detection temperature of a to-be-detected temperature object into an initial detection voltage according to the reference current, and the reference current is generated by the reference current generation module when an input bias voltage is input; the temperature detection module outputs a mirror base voltage according to the initial detection voltage and a rail voltage; the mirror current output module outputs a mirror detection current according to the mirror base voltage and the rail voltage; and the detection voltage output module outputs a detection voltage corresponding to the detection temperature according to the mirror detection current, and the detection voltage is used for conversion of the current temperature of the to-be-detected temperature object. The conversion from high-voltage end temperature detection to low-voltage output is realized, the influence of the fluctuation of the rail voltage on the temperature detection circuit is reduced, the accuracy of temperature detection is improved, and the safety and reliability of the to-be-detected temperature object during work are ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of temperature detection, in particular to a temperature detection circuit and device. BACKGROUND

[0002] At present, the commonly used temperature detection circuit adopts the mode of dividing voltage by upper end pull-up resistor and lower end thermistor, when the resistance value of the thermistor changes with temperature, the divided voltage at both ends will also change accordingly, so as to measure the temperature value according to the change of voltage, since the track voltage of the object to be measured is generally high, and the working voltage of the temperature measurement circuit is low, so it is necessary to supply power to the temperature measurement circuit alone, which leads to low accuracy of temperature measurement value, and cannot guarantee the safety of the equipment during operation. SUMMARY

[0003] The main purpose of the present application is to provide a temperature detection circuit and device, which aims to solve the technical problem of low accuracy of temperature measurement value in the prior art.

[0004] In order to achieve the above purpose, the present application provides a temperature detection circuit, which comprises: a reference current generation module, a temperature detection module, a mirror current output module and a detection voltage output module.

[0005] The first end of the reference current generation module is used for connecting a bias power supply, the second end of the reference current generation module is connected with the temperature detection module, and the temperature detection module is connected with the track voltage end of the object to be measured and the second end of the mirror current output module; one end of the mirror current output module is connected with the track voltage end, and the other end is connected with the voltage detection module;

[0006] The temperature detection module is used for converting the detection temperature of the object to be measured into an initial detection voltage according to the reference current, and the reference current is generated by the reference current generation module when the bias voltage is input by the bias power supply.

[0007] The temperature detection module is also used for outputting a mirror base voltage to the mirror current output module according to the initial detection voltage and the track voltage of the track voltage end.

[0008] The mirror current output module is used for outputting a mirror detection current to the detection voltage output module according to the mirror base voltage and the track voltage.

[0009] The detection voltage output module is used for outputting the detection voltage corresponding to the detection temperature according to the mirror detection current, and the detection voltage is used for converting the current temperature of the object to be measured.

[0010] Optionally, the temperature detection module comprises a temperature detection unit and a mirror base voltage output unit, a first end of the temperature detection unit is connected with the rail voltage end, a second end of the temperature detection unit is connected with a first end of the mirror base voltage output unit, a second end of the mirror base voltage output unit is connected with the mirror current output module, and a third end of the mirror base voltage output unit is connected with the reference current generation module.

[0011] The temperature detection unit is configured to detect a temperature of the object to be measured and convert the detected temperature into an initial detection voltage according to the reference current.

[0012] The mirror base voltage output unit is configured to output a mirror base voltage to the mirror current output module according to a rail voltage of the rail voltage end and the initial detection voltage.

[0013] Optionally, the mirror current output module comprises a mirror voltage conversion unit and a mirror current output unit, a second end of the mirror voltage conversion unit is connected with the temperature detection module, a first end of the mirror voltage conversion unit is connected with a second end of the mirror current output unit, a third end of the mirror voltage conversion unit is connected with the detection voltage output module, and a first end of the mirror current output unit is connected with the rail voltage end.

[0014] The mirror voltage conversion unit is configured to convert the mirror voltage into a mirror detection voltage based on the rail voltage.

[0015] The mirror current output unit is configured to generate a mirror detection current according to the mirror detection voltage output by the mirror voltage conversion unit.

[0016] Optionally, the reference current generation module comprises a bias voltage input unit and a reference current output unit, a first end of the bias voltage input unit is configured to be connected with the bias power supply, a second end of the bias voltage input unit is connected with the temperature detection module, a third end of the bias voltage input unit is connected with a first end of the reference current output unit, and a second end of the reference current output unit is grounded.

[0017] The bias voltage input unit is configured to output a reference voltage based on a bias voltage input by the bias power supply.

[0018] The reference current output unit is configured to generate a reference current based on the reference voltage.

[0019] Optionally, the temperature detection unit comprises a thermistor, and the mirror base voltage output unit comprises a first triode and a second resistor.

[0020] The first end of the thermistor is connected with the track voltage end, the second end of the thermistor is connected with the emitter of the first triode, the base of the first triode is connected with the collector of the first triode, the collector of the first triode is also connected with the first end of the second resistance, and the second end of the second resistance is connected with the reference current generation module.

[0021] Optionally, the mirror voltage conversion unit comprises a third triode and a fifth resistance, and the mirror current output unit comprises a fourth resistance.

[0022] The first end of the fourth resistance is connected with the track voltage end, the second end of the fourth resistance is connected with the emitter of the third triode, the base of the third triode is connected with the temperature detection module, the collector of the third triode is connected with the first end of the fifth resistance, and the second end of the fifth resistance is connected with the detection voltage output module.

[0023] Optionally, the bias voltage input unit comprises a second triode, and the reference current output unit comprises a third resistance.

[0024] The base of the second triode is connected with the bias power supply, the collector of the second triode is connected with the temperature detection module, the emitter of the second triode is connected with the first end of the third resistance, and the second end of the third resistance is grounded.

[0025] Optionally, the detection voltage output module comprises a sixth resistance.

[0026] The first end of the sixth resistance is connected with the mirror current output module, the second end of the sixth resistance is grounded, and the first end of the sixth resistance is the output end of the detection voltage.

[0027] Optionally, the object to be measured is a power transistor, and the pad of the first end of the thermistor is connected with the heat dissipation copper skin of the power transistor.

[0028] To achieve the above object, the application further provides a temperature detection device comprising the temperature detection circuit.

[0029] The application provides a temperature detection circuit, which comprises a reference current generation module, a temperature detection module, a mirror current output module and a detection voltage output module; a first end of the reference current generation module is used for connecting a bias power supply, a second end of the reference current generation module is connected with the temperature detection module, the temperature detection module is connected with a track voltage end of a temperature object to be detected and a second end of the mirror current output module; one end of the mirror current output module is connected with the track voltage end, and the other end is connected with the voltage detection module; the temperature detection module is used for converting a detection temperature of the temperature object to be detected into an initial detection voltage according to a reference current, the reference current being generated by the reference current generation module when the bias power supply inputs a bias voltage; the temperature detection module is also used for outputting a mirror base voltage to the mirror current output module according to the initial detection voltage and a track voltage of the track voltage end; the mirror current output module is used for outputting a mirror detection current to the detection voltage output module according to the mirror base voltage and the track voltage; and the detection voltage output module is used for outputting a detection voltage corresponding to the detection temperature according to the mirror detection current, the detection voltage being used for converting a current temperature of the temperature object to be detected. In the application, the temperature detection module is directly connected with the track voltage end of the temperature object to be detected, so that the temperature detection module can keep a close distance with the temperature object to be detected, thereby improving the accuracy of the temperature value. The reference current generation module outputs the reference current, the temperature detection module converts the detection temperature into the initial detection voltage based on the reference current, the mirror current output module outputs the mirror detection current based on the mirror base voltage and the track voltage, and the detection voltage output module outputs the detection voltage based on the mirror detection current, so that the conversion from the high-voltage end temperature detection to the low-voltage output is realized, the influence of the track voltage fluctuation on the temperature detection circuit is reduced, the accuracy of the temperature detection is improved, and the safety and reliability of the temperature object to be detected during operation are ensured. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from the drawings shown without any creative effort.

[0031] Figure 1 The functional module diagram of the first embodiment of the temperature detection circuit of the present application;

[0032] Figure 2 The functional module diagram of the second embodiment of the temperature detection circuit of the present application;

[0033] Figure 3 Fig. 1 is a schematic diagram of a circuit structure of a temperature detection circuit according to an embodiment of the present application;

[0034] Figure 4 Fig. 2 is a functional module diagram of a temperature detection circuit according to a third embodiment of the present application;

[0035] Figure 5 Fig. 1 is a schematic diagram of a circuit structure of a temperature detection circuit according to an embodiment of the present application;

[0036] Figure 6 Fig. 2 is a functional module diagram of a temperature detection circuit according to a third embodiment of the present application;

[0037] Figure 7 Fig. 1 is a schematic diagram of a circuit structure of a temperature detection circuit according to an embodiment of the present application.

[0038] Brief Description of the Drawings

[0039]

[0040]

[0041] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0043] It should be noted that all the directionality indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture (as shown in the drawings), and if the certain posture changes, the directionality indications also change accordingly.

[0044] In addition, the descriptions of "first", "second", etc. in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of the various embodiments can be combined with each other, but it must be based on the realization of the ordinary skilled in the art, and when the combination of the technical solutions contradicts each other or cannot be realized, it should be considered that the combination of the technical solutions does not exist, and is not within the protection scope of the present application.

[0045] The application provides a temperature detection circuit.

[0046] Referring to Figure 1 In the first embodiment of the temperature detection circuit, the temperature detection circuit comprises a reference current generation module 10, a temperature detection module 20, a mirror current output module 30 and a detection voltage output module 40.

[0047] The first end of the reference current generation module 10 is connected with a bias power supply Vb, the second end of the reference current generation module 10 is connected with the temperature detection module 20, the temperature detection module 20 is connected with a track voltage end p of a temperature object to be detected and the second end of the mirror current output module 30, one end of the mirror current output module 30 is connected with the track voltage end p, and the other end is connected with the voltage detection module 40.

[0048] The temperature detection module 20 is configured to convert a detection temperature of the temperature object to be detected into an initial detection voltage according to a reference current, wherein the reference current is generated by the reference current generation module 10 when the bias power supply inputs a bias voltage.

[0049] It can be understood that the temperature object to be detected can be an object that needs to be detected in temperature; the track voltage end can provide a working voltage for the temperature object to be detected; the voltage value of the bias voltage input by the bias power supply can be determined according to specific scenes; and the initial detection voltage can be a voltage generated based on a resistance corresponding to the reference current and the detection temperature.

[0050] The temperature detection module 20 is further configured to output a mirror base voltage to the mirror current output module 30 according to the initial detection voltage and a track voltage Vp of the track voltage end.

[0051] It can be understood that the mirror base voltage can be a high voltage capable of representing the detection temperature of the temperature object to be detected.

[0052] The mirror current output module 30 is configured to output a mirror detection current to the detection voltage output module 40 according to the mirror base voltage and the track voltage Vp.

[0053] It can be understood that the mirror detection current can be a low current capable of representing the detection temperature of the temperature object to be detected; and the mirror current output module can convert the high voltage representing the detection temperature of the temperature object to be detected into a low current output.

[0054] The detection voltage output module 40 is configured to output a detection voltage corresponding to the detection temperature according to the mirror detection current, and the detection voltage is used to convert a current temperature of the temperature object to be detected.

[0055] In the embodiment of the present application, the temperature detection module is directly connected with the track voltage end of the object to be measured, the bias power supply inputs bias voltage, the reference current generation module generates reference current, the temperature detection module converts the detection temperature of the object to be measured into initial detection voltage according to the reference current, and the mirror base voltage capable of representing the detection temperature is output according to the initial detection voltage and the track voltage of the track voltage end, the mirror current output module outputs mirror detection current according to the mirror base voltage and the track voltage, and the detection voltage output module outputs detection voltage used for converting the detection temperature of the object to be measured according to the mirror detection current.

[0056] The present application provides a temperature detection circuit, which comprises a reference current generation module, a temperature detection module, a mirror current output module and a detection voltage output module; a first end of the reference current generation module is used for connecting a bias power supply, a second end of the reference current generation module is connected with the temperature detection module, the temperature detection module is connected with a track voltage end of an object to be measured and a second end of the mirror current output module; one end of the mirror current output module is connected with the track voltage end, and the other end is connected with the voltage detection module; the temperature detection module is used for converting the detection temperature of the object to be measured into initial detection voltage according to reference current, the reference current is generated by the reference current generation module when the bias power supply inputs bias voltage; the temperature detection module is also used for outputting mirror base voltage to the mirror current output module according to the initial detection voltage and the track voltage of the track voltage end; the mirror current output module is used for outputting mirror detection current to the detection voltage output module according to the mirror base voltage and the track voltage; and the detection voltage output module is used for outputting detection voltage corresponding to the detection temperature according to the mirror detection current, and the detection voltage is used for converting the current temperature of the object to be measured. In the present application, the temperature detection module is directly connected with the track voltage end of the object to be measured, so that the temperature measurement module can keep a close distance with the object to be measured, thereby improving the accuracy of the temperature measurement value; the reference current generation module outputs reference current, the temperature detection module converts the detection temperature into initial detection voltage based on the reference current, and outputs mirror base voltage according to the initial detection voltage and the track voltage, the mirror current output module outputs mirror detection current according to the mirror base voltage and the track voltage, and the detection voltage output module outputs detection voltage according to the mirror detection current, thereby realizing the conversion from high-voltage temperature detection to low-voltage output, reducing the influence of track voltage fluctuation on the temperature measurement circuit, improving the accuracy of temperature detection, and thereby ensuring the safety and reliability of the object to be measured during operation.

[0057] Reference Figure 2In the second embodiment of the temperature detection circuit, the temperature detection module 20 comprises a temperature detection unit 201 and a mirror base voltage output unit 202, a first end of the temperature detection unit 201 is connected with the rail voltage end p, a second end of the temperature detection unit 201 is connected with a first end of the mirror base voltage output unit 202, a second end of the mirror base voltage output unit 202 is connected with the mirror current output module 30, and a third end of the mirror base voltage output unit 202 is connected with the reference current generation module 10.

[0058] The temperature detection unit 201 is configured to detect the temperature of the object to be measured and convert the detected temperature into an initial detection voltage according to the reference current.

[0059] The mirror base voltage output unit 202 is configured to output a mirror base voltage to the mirror current output module 30 according to the rail voltage of the rail voltage end and the initial detection voltage.

[0060] In the embodiment, the temperature detection unit in the temperature detection module detects the temperature of the object to be measured and converts the detected temperature into an initial detection voltage according to the reference current, and the mirror base voltage output unit outputs a mirror base voltage to the mirror current output module according to the rail voltage and the initial detection voltage.

[0061] Further, in order to improve the accuracy of the temperature measurement value, the temperature detection unit 201 comprises a thermistor R1, and the mirror base voltage output unit 202 comprises a first triode T1 and a second resistor R2. Figure 3 The first end of the thermistor R1 is connected with the rail voltage end p, the second end of the thermistor R1 is connected with the emitter of the first triode T1, the base of the first triode T1 is connected with the collector of the first triode T1, the collector of the first triode T1 is further connected with the first end of the second resistor R2, and the second end of the second resistor R2 is connected with the reference current generation module 10.

[0062] It can be understood that the initial detection voltage is the voltage across the thermistor R1, and the mirror voltage is the base voltage of the first triode T1. Since the first triode T1 works in an amplification state, the current flowing through the thermistor R1 is equal to the reference current output by the reference current generation module, and the reference current can be represented as Iin, so that the base voltage of the first triode T1 is Vp-Veb-Iin*R1, wherein Veb is the voltage between the emitter and the base of the first triode. The second resistor R2 is a voltage dividing resistor.

[0063] Further, the temperature detection circuit can be applied to temperature detection of a power transistor, in order to make the thermistor close to the object to be detected, so as to improve the accuracy of the temperature detection value.

[0064] The temperature detection module in the embodiment comprises a temperature detection unit and a mirror base voltage output unit, a first end of the temperature detection unit is connected with the rail voltage end, a second end of the temperature detection unit is connected with a first end of the mirror base voltage output unit, a second end of the mirror base voltage output unit is connected with the mirror current output module, and a third end of the mirror base voltage output unit is connected with the reference current generation module; the temperature detection unit is used for detecting the temperature of the object to be detected and converting the detected temperature into an initial detection voltage according to the reference current; and the mirror base voltage output unit is used for outputting a mirror base voltage to the mirror current output module according to the rail voltage of the rail voltage end and the initial detection voltage. The detected temperature of the object to be detected is converted into an initial detection temperature by the temperature detection unit, and then the mirror base voltage output unit outputs a mirror base voltage to the mirror current output module according to the initial detection temperature, so that high-voltage temperature detection is converted into low-voltage output, the influence of rail voltage fluctuation on the temperature detection circuit is reduced, and the accuracy of the temperature detection value is improved.

[0065] Reference Figure 4 In the third embodiment of the temperature detection circuit, the mirror current output module 30 comprises a mirror voltage conversion unit 301 and a mirror current output unit 302, a second end of the mirror voltage conversion unit 301 is connected with the temperature detection module 20, a first end of the mirror voltage conversion unit 301 is connected with a second end of the mirror current output unit 302, a third end of the mirror voltage conversion unit 301 is connected with the detection voltage output module 40, and a first end of the mirror current output unit 301 is connected with the rail voltage end p.

[0066] The mirror voltage conversion unit 301 is used for converting the mirror voltage into a mirror detection voltage based on the rail voltage.

[0067] It can be understood that the mirror detection voltage can be a voltage used for generating a mirror detection current.

[0068] The mirror current output unit 302 is used for generating a mirror detection current according to the mirror detection voltage output by the mirror voltage conversion unit.

[0069] In the embodiment of the present application, the mirror voltage conversion unit generates a mirror detection voltage according to the track voltage and the mirror voltage input by the temperature detection module, the mirror current output module generates a mirror detection current based on the mirror detection voltage, and the detection voltage output module converts the mirror detection current into a detection voltage corresponding to the detection temperature, so that the temperature corresponding to the to-be-measured temperature can be calculated through the detection voltage.

[0070] Further, in order to reduce the influence of track voltage fluctuation on the temperature measurement circuit and improve the accuracy of the temperature measurement value, with reference to Figure 5 The mirror voltage conversion unit 301 comprises a third transistor T3 and a fifth resistor R5, and the mirror current output unit 302 comprises a fourth resistor R4. The first end of the fourth resistor R4 is connected with the track voltage end p, the second end of the fourth resistor R4 is connected with the emitter of the third transistor T3, the base of the third transistor T3 is connected with the temperature detection module 20, the collector of the third transistor T3 is connected with the first end of the fifth resistor R5, and the second end of the fifth resistor R5 is connected with the detection voltage output module 40.

[0071] It can be understood that the fifth resistor R5 is a voltage dividing resistor, the base voltage of the third transistor T3 is equal to the mirror voltage, the third transistor T3 works in an amplification state, and the voltage across the fourth resistor R4 is Vp-(Vp-Veb-Iin*R1)-Veb. The current flowing through the fourth resistor R4 is Iin*R1 / R4, and the voltage across the fourth resistor R4 is the mirror detection voltage.

[0072] In the embodiment of the present application, the mirror current output module comprises a mirror voltage conversion unit and a mirror current output unit. The second end of the mirror voltage conversion unit is connected with the temperature detection module, the first end of the mirror voltage conversion unit is connected with the second end of the mirror current output unit, the third end of the mirror voltage conversion unit is connected with the detection voltage output module, and the first end of the mirror current output unit is connected with the track voltage end. The mirror voltage conversion unit is configured to convert the mirror voltage into a mirror detection voltage based on the track voltage. The mirror current output unit is configured to generate a mirror detection current according to the mirror detection voltage output by the mirror voltage conversion unit. By converting the mirror voltage into the mirror detection voltage and then converting the mirror detection voltage into the mirror detection current, the influence of track voltage fluctuation on the temperature measurement circuit is reduced, and the accuracy of the temperature measurement value is improved.

[0073] With reference to Figure 6In the fourth embodiment of the temperature detection circuit, the reference current generation module 10 comprises a bias voltage input unit 101 and a reference current output unit 102, the first end of the bias voltage input unit 101 is connected to the bias power supply, the second end of the bias voltage input unit 101 is connected to the temperature detection module 20, the third end of the bias voltage input unit 101 is connected to the first end of the reference current output unit 102, and the second end of the reference current output unit 102 is grounded.

[0074] The bias voltage input unit 101 is configured to output a reference voltage based on the bias voltage input by the bias power supply.

[0075] The reference current output unit 102 is configured to generate a reference current based on the reference voltage.

[0076] In the embodiments of the present application, the bias voltage input unit outputs a reference voltage based on the bias voltage, and the reference current output unit generates a reference current based on the reference voltage.

[0077] Further, in order to improve the accuracy of the temperature measurement value, with reference to Figure 7 The bias voltage input unit 101 comprises a second transistor T3, and the reference current output unit 102 comprises a third resistor R3.

[0078] The base of the second transistor T2 is connected to the bias power supply, the collector of the second transistor T2 is connected to the temperature detection module 20, the emitter of the second transistor T2 is connected to the first end of the third resistor R3, and the second end of the third resistor R3 is grounded.

[0079] It can be understood that the bias voltage input at the base of the second transistor T2 is Vb, so that the voltage across the third resistor R3 is Vb-Veb, which is the reference voltage, wherein Vbe is the voltage between the base and the emitter of the second transistor, the current flowing through the third resistor R3 is Iin=(Vb-Veb) / R3, and the base current of the second transistor T2 is small and can be ignored, so the current flowing through the third resistor R3 is the reference current.

[0080] Further, in order to reduce the influence of the track voltage on the temperature measurement circuit and improve the accuracy of the temperature measurement value, with reference to Figure 7 The detection voltage output module 40 comprises a sixth resistor R6, the first end of the sixth resistor R6 is connected to the mirror current output module 30, the second end of the sixth resistor R6 is grounded, and the first end of the sixth resistor R6 is the output end of the detection voltage.

[0081] It can be understood that the detection voltage is the voltage across the sixth resistor R6, and the sixth resistor R6 converts the mirror detection current into a detection voltage output.

[0082] In an alternative embodiment, continuing to refer to Figure 7 , the temperature detection circuit comprises R1, R2, R3, R4, R5, R6, T1, T2 and T3, R1 is a thermistor for temperature measurement, T1 and T3 are PNP triodes, and T2 is an NPN triode; one end of R1 is directly connected to the rail voltage end of the power transistor, and the other end is connected to the emitter stage of T1, the base and the collector of T1 are connected to make the triode in an amplification state, the base of T1 is connected to the base of T3 to make the base currents equal, and changing the resistance value of R4 can change the detection voltage Vout, thereby playing a role in adjusting the output sensitivity of the temperature detection circuit; R2 and R5 are voltage dividing resistors and have the same resistance value; the base of T2 inputs a bias voltage Vb, and a reference current is generated in combination with resistor R3; Vout is the output of this temperature detection circuit, and one end of resistor R6 is grounded, so that the voltage value generated on resistor R6 by the mirror detection current of the detection output can realize temperature detection.

[0083] Specifically, the base of triode T2 inputs Vb, so that the current flowing through resistor R3 is Iin=(Vb-Vbe) / R3, the base current is small and can be ignored, and since triodes T1 and T2 work in an amplification state, the current values flowing through resistors R2 and thermistor R1 are also Iin, so that the base voltage of triode T1 is Vp-Veb-Iin*R1, since the bases of T1 and T3 are connected, the base voltage of T3 is also Vp-Veb-Iin*R1, and T3 also works in an amplification state, so that the current flowing through resistor R4 is IOUT=[Vp-(Vp-Veb-Iin*R1)-Veb] / R4=Iin*R1 / R4, and the currents flowing through resistors R5 and R6 are also IOUT, so the detection voltage output is:

[0084] Vout=IOUT*R6=Iin*R1 / R4*R6=(Vb-Vbe)*R1*R6 / (R3*R4), wherein Vb, Vbe, R6, R3 and R4 are known quantities, so that the resistance value of thermistor R1 can be obtained through the detection voltage value, thereby obtaining the detected temperature value, and temperature detection and protection of the power transistor are realized.

[0085] It needs to be explained that one end of the thermistor is connected with the track voltage end of the power transistor, the pad of the thermistor can be directly connected with the heat dissipation copper skin of the power transistor in electrical connection, the accuracy and sensitivity of temperature measurement are enhanced, the safety and reliability of the equipment during working are improved by more accurate temperature measurement, and the user obtains better experience;Through the design of the mirror current source, the thermistor can realize temperature detection under high voltage, and relatively low output voltage is obtained at the output end of the mirror current source, so that the conversion from high voltage detection to low voltage output is realized, which is convenient for further processing of the rear circuit, and through derivation, it can be obtained that the detection voltage of the final output of the circuit is irrelevant to the track voltage of the power transistor, on the one hand, the stability of the temperature detection circuit is further improved, and on the other hand, the circuit has greater flexibility, and accurate temperature measurement and protection can be realized under different working voltages of different equipment.

[0086] The reference current generation module of the embodiment of the application comprises a bias voltage input unit and a reference current output unit, a first end of the bias voltage input unit is used for connecting the bias power supply, a second end of the bias voltage input unit is connected with the temperature detection module, a third end of the bias voltage input unit is connected with a first end of the reference current output unit, and a second end of the reference current output unit is grounded;The bias voltage input unit is used for outputting a reference voltage based on the bias voltage input by the bias power supply;The reference current output unit is used for generating a reference current based on the reference voltage. The mirror base voltage can be output based on the reference current, and the accuracy of the temperature detection circuit is improved.

[0087] To achieve the above object, the application further provides a temperature detection device comprising the temperature detection circuit as described above. The specific structure of the circuit is referred to the above embodiment. Since the device adopts all the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0088] The above only describes the preferred embodiments of the application, and does not limit the patent scope of the application, any equivalent structural transformation made by referring to the content of the specification and drawings of the application, or direct / indirect application in other related technical fields is included in the patent protection scope of the application.

Claims

1. A temperature detection circuit, characterized by comprising: The temperature detection circuit comprises a reference current generation module, a temperature detection module, a mirror current output module and a detection voltage output module; A first end of the reference current generation module is used for connecting a bias power supply, a second end of the reference current generation module is connected with the temperature detection module, the temperature detection module is connected with a track voltage end of a temperature object to be detected and a second end of the mirror current output module; one end of the mirror current output module is connected with the track voltage end, and the other end is connected with the voltage detection module, and the track voltage end can provide a working voltage for the temperature object to be detected; The temperature detection module is used for converting a detection temperature of the temperature object to be detected into an initial detection voltage according to a reference current, the reference current is generated by the reference current generation module when a bias voltage is input by the bias power supply, and the initial detection voltage is a voltage generated based on a resistance corresponding to the reference current and the detection temperature; The temperature detection module is further used for outputting a mirror base voltage to the mirror current output module according to the initial detection voltage and a track voltage of the track voltage end, and the mirror base voltage is a high voltage representing the detection temperature; The mirror current output module is used for outputting a mirror detection current to the detection voltage output module according to the mirror base voltage and the track voltage, and the mirror detection current is a low current representing the detection temperature, and the mirror current output module can convert the high voltage into the low current; The detection voltage output module is used for outputting a detection voltage corresponding to the detection temperature according to the mirror detection current, and the detection voltage is used for converting a current temperature of the temperature object to be detected.

2. The temperature detection circuit according to claim 1, wherein The temperature detection module comprises a temperature detection unit and a mirror base voltage output unit, a first end of the temperature detection unit is connected with the track voltage end, a second end of the temperature detection unit is connected with a first end of the mirror base voltage output unit, a second end of the mirror base voltage output unit is connected with the mirror current output module, and a third end of the mirror base voltage output unit is connected with the reference current generation module; The temperature detection unit is used for detecting a temperature of the temperature object to be detected and converting the detection temperature into an initial detection voltage according to the reference current; The mirror base voltage output unit is used for outputting a mirror base voltage to the mirror current output module according to a track voltage of the track voltage end and the initial detection voltage.

3. The temperature detection circuit according to claim 1, wherein The mirror current output module comprises a mirror voltage conversion unit and a mirror current output unit, a second end of the mirror voltage conversion unit is connected with the temperature detection module, a first end of the mirror voltage conversion unit is connected with a second end of the mirror current output unit, a third end of the mirror voltage conversion unit is connected with the detection voltage output module, and a first end of the mirror current output unit is connected with the track voltage end; The mirror voltage conversion unit is used for converting the mirror voltage into a mirror detection voltage based on the track voltage. The mirror current output unit is configured to generate a mirror detection current according to a mirror detection voltage output by the mirror voltage conversion unit.

4. The temperature detection circuit according to any one of claims 1 to 3, wherein The reference current generation module comprises a bias voltage input unit and a reference current output unit, a first end of the bias voltage input unit is configured to be connected to the bias power supply, a second end of the bias voltage input unit is connected to the temperature detection module, a third end of the bias voltage input unit is connected to a first end of the reference current output unit, and a second end of the reference current output unit is grounded. The bias voltage input unit is configured to output a reference voltage based on a bias voltage input by the bias power supply. The reference current output unit is configured to generate a reference current based on the reference voltage.

5. The temperature sensing circuit of claim 2, wherein, The temperature detection unit comprises a thermistor, and the mirror base voltage output unit comprises a first transistor and a second resistor. A first end of the thermistor is connected to the rail voltage end, a second end of the thermistor is connected to an emitter of the first transistor, a base of the first transistor is connected to a collector of the first transistor, the collector of the first transistor is also connected to a first end of the second resistor, and a second end of the second resistor is connected to the reference current generation module.

6. The temperature sensing circuit of claim 3, wherein, The mirror voltage conversion unit comprises a third transistor and a fifth resistor, and the mirror current output unit comprises a fourth resistor. A first end of the fourth resistor is connected to the rail voltage end, a second end of the fourth resistor is connected to an emitter of the third transistor, a base of the third transistor is connected to the temperature detection module, a collector of the third transistor is connected to a first end of the fifth resistor, and a second end of the fifth resistor is connected to the detection voltage output module.

7. The temperature sensing circuit of claim 4, wherein, The bias voltage input unit comprises a second transistor, and the reference current output unit comprises a third resistor. A base of the second transistor is connected to the bias power supply, a collector of the second transistor is connected to the temperature detection module, an emitter of the second transistor is connected to a first end of the third resistor, and a second end of the third resistor is grounded.

8. The temperature sensing circuit of any one of claims 1-3, wherein, The detection voltage output module comprises a sixth resistor. A first end of the sixth resistor is connected to the mirror current output module, a second end of the sixth resistor is grounded, and the first end of the sixth resistor is an output end of the detection voltage.

9. The temperature sensing circuit of claim 5, wherein, The object to be measured is a power transistor, and a pad of the first end of the thermistor is connected to a heat dissipation copper skin of the power transistor.

10. A temperature detecting device characterized by comprising: The device comprises the temperature detection circuit according to any one of claims 1-9.

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