A temperature detection circuit

Abstract

The application provides a temperature detection circuit, comprising: a constant current source for outputting a constant current; a thermistor electrically connected with the constant current source, for sensing an ambient temperature and generating a corresponding resistance value change; a temperature output module electrically connected with the thermistor, for calculating the ambient temperature based on a voltage difference between the thermistor; and a temperature drift correction module electrically connected with the constant current source and the thermistor, respectively, wherein the temperature drift correction module is in the same environment as the thermistor and has a drift characteristic opposite to a resistance temperature drift change trend of the thermistor; the temperature drift correction module is used for adjusting the size of the constant current based on a temperature drift change amount generated by the temperature drift correction module itself, so that the output current of the constant current source has a current drift opposite to the resistance temperature drift of the thermistor, thereby offsetting the inherent resistance temperature drift of the thermistor. The temperature detection circuit provided by the application solves the problems of significant temperature drift influence, insufficient anti-interference capability, lack of hardware compensation and high system complexity in the prior art.

Description

Technical Field

[0001] This invention relates to the field of electronic measurement technology, and in particular to a temperature detection circuit. Background Technology

[0002] The temperature detection principle of a thermistor is based on the fact that its resistance value changes with temperature in a quasi-linear positive temperature coefficient. The resistance signal is converted into a voltage signal that can be processed by a microprocessor or analog-to-digital converter (ADC), which usually relies on a bridge circuit or a constant current source drive circuit.

[0003] Existing technologies mostly use discrete constant current sources, general-purpose operational amplifiers, or common commercial constant current devices to drive thermistors.

[0004] However, such solutions generally suffer from drawbacks such as large temperature drift of the excitation current and poor long-term consistency. In addition, traditional circuits are susceptible to common-mode interference and lead resistance coupling during long lead transmission, making it difficult to meet the high-reliability measurement requirements under industrial-grade temperatures of -40℃ to 125℃. Summary of the Invention

[0005] This invention provides a temperature detection circuit that solves the problems of significant temperature drift, insufficient anti-interference capability, lack of hardware compensation, and high system complexity in existing temperature detection circuits by using reverse current compensation to offset the measurement error caused by the temperature drift of the inherent resistance of the thermistor.

[0006] In a first aspect, an embodiment of the present invention provides a temperature detection circuit, comprising: a constant current source for outputting a constant current; a thermistor electrically connected to the constant current source for sensing ambient temperature and generating a corresponding resistance change; a temperature output module electrically connected to the thermistor for calculating the ambient temperature based on the voltage difference across the thermistor; and a temperature drift correction module electrically connected to both the constant current source and the thermistor, wherein the temperature drift correction module is in the same environment as the thermistor and has a drift characteristic opposite to the temperature drift trend of the thermistor; the temperature drift correction module is used to adjust the magnitude of the constant current based on its own temperature drift change with temperature, so that the output current of the constant current source has a current drift opposite to the temperature drift of the thermistor, thereby offsetting the inherent resistance temperature drift of the thermistor itself.

[0007] Optionally, the temperature drift correction module includes: a reference unit for generating a constant base control current; a temperature drift sensing unit, which is located in the same temperature field as the thermistor and has a negative temperature characteristic where the voltage drop across its terminals decreases as the temperature increases; and a current correction unit, which is electrically connected to the drive terminals of the reference unit, the temperature drift sensing unit, and the constant current source, respectively, for generating a correction current based on the voltage drop generated by the temperature drift sensing unit as the temperature changes; the base control current and the correction current are superimposed to form a total control current to control the output current of the constant current source.

[0008] Optionally, the temperature output module includes: a differential amplifier unit, electrically connected to the thermistor, for acquiring and amplifying the voltage difference across the thermistor; and an analog-to-digital converter unit, electrically connected to the differential amplifier unit, for converting the voltage difference across the thermistor into ambient temperature based on a preset conversion rule.

[0009] Optionally, the temperature output module also includes a nonlinear correction unit, which is electrically connected to the analog-to-digital converter unit, and is used to perform nonlinear correction on the signal output by the analog-to-digital converter unit to compensate for the resistance-temperature nonlinearity of the thermistor.

[0010] Optionally, the constant current source includes an input terminal, an output terminal, and a control terminal; the input terminal of the constant current source is electrically connected to a reference power supply; the output terminal of the constant current source is electrically connected to a thermistor; and the control terminal of the constant current source is electrically connected to the output terminal of the constant current source via a reference unit.

[0011] Optionally, the reference unit includes a first resistor; the temperature drift sensing unit includes a first diode; the current correction unit includes a second resistor; the control terminal of the constant current source is electrically connected to the output terminal of the constant current source via the first resistor. The anode of the first diode is electrically connected to the output terminal of the constant current source, and the cathode is electrically connected to a thermistor; the second resistor is electrically connected to both the control terminal of the constant current source and the cathode of the first diode.

[0012] Optionally, the differential amplifier unit includes an operational amplifier; the analog-to-digital converter unit includes an analog-to-digital converter, a third resistor, a fourth resistor, a fifth resistor, and a sixth resistor: the non-inverting input of the operational amplifier is electrically connected to the first terminal of the thermistor through the third resistor and grounded through the fourth resistor; the inverting input of the operational amplifier is electrically connected to the second terminal of the thermistor through the fifth resistor and grounded; the output of the operational amplifier is electrically connected to the inverting input of the operational amplifier through the sixth resistor; and the analog-to-digital converter is electrically connected to the output of the operational amplifier.

[0013] Optionally, the differential amplification unit has a magnification factor of 10-12 times.

[0014] Optionally, the temperature drift correction module has a temperature drift compensation range of -40℃ to 125℃.

[0015] Optionally, the thermistor is a two-wire platinum resistance thermometer.

[0016] This invention provides a temperature detection circuit in which a temperature drift correction module is deployed in the same environment as the thermistor and has opposite resistance temperature drift characteristics. The module can adjust the constant current source output current in real time according to changes in ambient temperature, causing the current to drift in the opposite direction to the thermistor's resistance temperature drift. This reverse current compensation method offsets the measurement error caused by the thermistor's inherent resistance temperature drift (a reversible change in resistance caused by changes in ambient temperature), stabilizing the detection voltage across the thermistor and effectively improving the linearity and accuracy of temperature detection across the entire temperature range. Furthermore, by employing a high-precision ΣΔ type ADC, the nonlinear characteristics of the thermistor (including the slight nonlinearity remaining after compensation by the temperature drift correction module, or the irreversible change in resistance caused by long-term use of the component or environmental stress) are corrected for nonlinearity, thereby obtaining high-precision, high-linearity temperature detection results across the entire temperature range and measurement range. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a temperature detection circuit provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of another temperature detection circuit provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the circuit principle of a temperature detection circuit provided in an embodiment of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be fully described below with reference to the accompanying drawings in the embodiments of this invention, through specific implementation methods. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort fall within the protection scope of this invention.

[0019] Figure 1 This is a schematic diagram of a temperature detection circuit provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of another temperature detection circuit provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of a temperature detection circuit according to an embodiment of the present invention. The temperature detection circuit provided in this embodiment can be specifically applied in scenarios such as industrial sites, automotive electronics, or outdoor equipment where high accuracy is required and ambient temperature changes are drastic. This circuit is used to eliminate measurement errors caused by the temperature drift characteristics of the thermistor. (Reference) Figures 1 to 3This invention provides a temperature detection circuit, comprising: a constant current source U1 for outputting a constant current; a thermistor R electrically connected to the constant current source U1 for sensing ambient temperature and generating a corresponding resistance change; a temperature output module 10 electrically connected to the thermistor R for calculating the ambient temperature based on the voltage difference across the thermistor R; and a temperature drift correction module 20 electrically connected to both the constant current source U1 and the thermistor R, wherein the temperature drift correction module 20 is in the same environment as the thermistor R and has a drift characteristic opposite to the temperature drift trend of the thermistor R; the temperature drift correction module 20 is used to adjust the magnitude of the constant current based on its own temperature drift change with temperature, so that the output current of the constant current source U1 has a current drift opposite to the temperature drift of the thermistor R, thereby offsetting the inherent resistance temperature drift of the thermistor R.

[0020] Specifically, during operation, the constant current source U1 outputs a basic constant current I, which flows through the thermistor R connected in parallel with the temperature output module 10 to generate a voltage. This voltage is acquired by the temperature output module 10, which then calculates the current ambient temperature corresponding to the voltage. Simultaneously, the temperature drift correction module 20, located in the same environment, senses the ambient temperature in real time and adjusts the output current of the constant current source U1 based on its opposite resistance temperature drift trend to the thermistor R (i.e., when the thermistor R is NTC, the temperature drift correction module 20 selects PTC; conversely, the temperature drift correction module 20 adjusts the temperature drift to maintain the stability of the voltage across the thermistor R). When the ambient temperature rises and causes the resistance of the thermistor R to decrease, the temperature drift correction module 20 simultaneously reduces the output current of the constant current source U1, thereby maintaining the stability of the voltage across the thermistor R; conversely, when the temperature decreases, it increases the output current. Through reverse drift compensation, the output current of the constant current source U1 has a current drift that is opposite to the resistance temperature drift of the thermistor R, thus offsetting the inherent resistance temperature drift of the thermistor R itself and improving the linearity and full-temperature-range accuracy of temperature detection.

[0021] The temperature detection circuit provided in this invention features a constant current source outputting a constant current, a thermistor sensing the ambient temperature and generating a resistance change, and a temperature output module calculating the ambient temperature based on the voltage difference across the thermistor. A temperature drift correction module, deployed in the same environment as the thermistor, possesses opposite resistance temperature drift characteristics. It can adjust the constant current source output current in real time according to changes in ambient temperature, causing the current to drift in the opposite direction to the thermistor's resistance temperature drift. This reverse current compensation method offsets the measurement error caused by the inherent resistance temperature drift of the thermistor, stabilizes the detection voltage across the thermistor, and effectively improves the linearity and full-temperature-range detection accuracy of the temperature detection.

[0022] It should be noted that resistor temperature drift includes aging temperature drift (irreversible change in resistance caused by long-term use of components or environmental stress) and temperature drift (reversible change in resistance caused by changes in ambient temperature). This application addresses the temperature drift of the thermistor R, that is, by using reverse drift compensation of the circuit to make the temperature output module 10 linear across the entire temperature range.

[0023] Furthermore, in an optional embodiment, the temperature output module 10 employs a high-precision ΣΔ ADC. This ADC performs high-resolution sampling of the analog voltage difference across the thermistor R, and uses an internally integrated digital filter and lookup table (or polynomial fitting algorithm) to perform nonlinear correction on the nonlinear characteristics of the thermistor R (including the slight nonlinearity remaining after compensation by the temperature drift correction module 20, or the irreversible change in resistance caused by long-term use of the component or environmental stress), thereby obtaining high-precision and high-linearity temperature detection results across the entire temperature range and measurement range.

[0024] Optionally, the temperature drift correction module 20 includes: a reference unit 21 for generating a constant base control current; a temperature drift sensing unit 22, which is set in the same temperature field as the thermistor R and has a negative temperature characteristic that the voltage drop across its terminals decreases as the temperature increases; and a current correction unit 23, which is electrically connected to the reference unit 21, the temperature drift sensing unit 22, and the driving terminal of the constant current source U1, respectively, for generating a correction current based on the voltage drop generated by the temperature drift sensing unit 22 as the temperature changes; the base control current generated by the reference unit 21 and the correction current generated by the current correction unit 23 are superimposed to form a total control current to control the output current of the constant current source U1.

[0025] Specifically, the reference unit 21 outputs a constant base control current that does not change with temperature. The temperature drift sensing unit 22 and the thermistor R are installed in the same temperature field, and the voltage drop across its terminals decreases as the temperature rises. This voltage drop is converted to generate a correction current proportional to the voltage drop of the temperature drift sensing unit 22. This correction current is superimposed on the base control current generated by the reference unit 21 at the input node of the constant current source U1 to form the total control current. The total control current determines the magnitude of the output current of the constant current source U1 based on the internal proportional relationship of the constant current source U1. The correction current increases accordingly with the rise in ambient temperature, thus causing the output current of the constant current source U1 to rise synchronously with the temperature. For the NTC type thermistor R, its resistance decreases with the rise in temperature. At this time, the increasing trend of the output current of the constant current source U1 and the decreasing trend of the resistance of the thermistor R compensate for each other, which can stabilize the voltage across the thermistor R and effectively suppress the interference caused by ambient temperature fluctuations on the temperature measurement signal.

[0026] Optionally, the temperature output module 10 includes: a differential amplifier unit 11, electrically connected to the thermistor R, for acquiring and amplifying the voltage difference across the thermistor R; and an analog-to-digital converter unit 12, electrically connected to the differential amplifier unit 11, for converting the voltage difference across the thermistor R into ambient temperature based on a preset conversion rule.

[0027] The preset conversion rule can be understood as the voltage-temperature correspondence pre-stored in the analog-to-digital conversion unit 12.

[0028] Specifically, the temperature output module 10 includes a differential amplifier unit 11 and an analog-to-digital converter unit 12. The differential amplifier unit 11 acquires a weak voltage difference signal from across the thermistor R and amplifies it (e.g., by 10-12 times) to make its amplitude match the full-scale input range of the subsequent analog-to-digital converter unit 12. The amplified voltage signal is then sent to the analog-to-digital converter unit 12. The analog-to-digital converter unit 12 converts the currently input voltage value into the corresponding ambient temperature output in real time according to a preset voltage-temperature correspondence rule.

[0029] Optionally, the temperature output module 10 also includes a nonlinear correction unit 13, which is electrically connected to the analog-to-digital conversion unit 12, for performing nonlinear correction on the signal output by the analog-to-digital conversion unit 12 to compensate for the resistance-temperature nonlinear characteristics of the thermistor R.

[0030] Specifically, the temperature output module 10 also includes a nonlinear correction unit 13, which is electrically connected to the analog-to-digital converter 12. After the analog-to-digital converter 12 converts the voltage signal of the thermistor R into a raw digital value (proportional to the resistance value), the nonlinear correction unit 13 performs nonlinear correction calculations on the raw digital value according to the pre-calibrated resistance-temperature characteristic curve of the thermistor R, eliminating the error caused by the nonlinearity of resistance with temperature change due to the material properties of the thermistor R itself, and outputting a linearized temperature value.

[0031] refer to Figure 3 In an optional embodiment, the constant current source U1 includes an input terminal V+, an output terminal V-, and a control terminal R; the input terminal V+ of the constant current source U1 is electrically connected to a reference power supply; the output terminal V- of the constant current source U1 is electrically connected to a thermistor R; and the control terminal R of the constant current source U1 is electrically connected to the output terminal V- of the constant current source U1 via the reference unit 21.

[0032] Specifically, the constant current source U1 includes an input terminal V+, an output terminal V-, and a control terminal R. The input terminal V+ of the constant current source U1 is electrically connected to a reference power supply (such as a 5V or 3.3V regulated power supply) to obtain the operating voltage; the output terminal V- of the constant current source U1 is electrically connected to one end of a thermistor R, providing excitation current to the thermistor R; the control terminal R of the constant current source U1 is electrically connected to the output terminal V- of the constant current source U1 via a reference unit 21 (i.e., the reference unit 21 is located between the control terminal R and the output terminal V-), forming a feedback closed loop: the reference unit 21 stabilizes the voltage relationship between the output terminal V- and ground or the current relationship between the output terminal V- and the control terminal R, thereby ensuring that the current output by the constant current source U1 is only controlled by the temperature drift correction module 20 and the reference unit 21, and is not affected by load changes.

[0033] Optionally, the reference unit 21 includes a first resistor R1; the temperature drift sensing unit 22 includes a first diode D1; the current correction unit 23 includes a second resistor R2; the control terminal R of the constant current source U1 is electrically connected to the output terminal V- of the constant current source U1 via the first resistor R1. The anode of the first diode D1 is electrically connected to the output terminal V- of the constant current source U1, and the cathode is electrically connected to the thermistor R; the second resistor R2 is electrically connected to both the control terminal R of the constant current source U1 and the cathode of the first diode D1.

[0034] Specifically, when the ambient temperature rises, the forward voltage drop of the first diode D1 decreases, causing its cathode potential (i.e., the potential at the upper end of the thermistor R) to rise relative to the output terminal V-. This potential difference is converted into a correction current flowing into the control terminal R of the constant current source U1 through the second resistor R2. This correction current is superimposed on the reference current flowing through the first resistor R1, raising the reference potential of the control terminal R, thereby increasing the output current of the constant current source U1. Since the resistance of the thermistor R decreases (for NTC type) or increases (for PTC type) with increasing temperature, adjusting the circuit polarity can compensate for the direction of the output current change with the direction of the resistance change, stabilizing the voltage across the thermistor and offsetting the measurement error caused by the temperature drift of the resistor.

[0035] Optionally, the differential amplifier unit 11 includes an operational amplifier U2.1; the analog-to-digital converter unit 12 includes an analog-to-digital converter (ADC), a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6. The non-inverting input terminal 3 of the operational amplifier U2.1 is electrically connected to the first terminal of the thermistor R through the third resistor R3, and grounded through the fourth resistor R4; The inverting input terminal 2 of operational amplifier U2.1 is electrically connected to the second terminal of the thermistor R through the fifth resistor R5, and is grounded; Output terminal 1 of operational amplifier U2.1 is electrically connected to the inverting input terminal of operational amplifier U2.1 through the sixth resistor R6; The analog-to-digital converter (ADC) is electrically connected to output terminal 1 of the operational amplifier U2.1.

[0036] Specifically, the voltage at the first terminal of the thermistor R is input to the non-inverting input 3 of operational amplifier U2.1 through the third resistor R3; simultaneously, this input is grounded through the fourth resistor R4, establishing a stable DC bias. The voltage at the second terminal of the thermistor R is input to the inverting input 2 of operational amplifier U2.1 through the fifth resistor R5; this input is simultaneously connected to the output 1 of operational amplifier U2.1 through the sixth resistor R6, forming negative feedback. In this differential amplifier topology, the overall differential gain of the circuit is G = R6 / R5. When the voltage difference ΔV across the thermistor R changes, the output voltage of operational amplifier U2.1 is Vout = (R6 / R5) × ΔV (the ratio of R3 / R4 is matched with R6 / R5). The amplified analog voltage signal V_out is directly fed into the analog-to-digital converter (ADC) for sampling and quantization, converting it into the corresponding digital temperature value. This differential amplifier structure has common-mode rejection characteristics, which can effectively suppress common-mode noise (such as ground potential noise and power supply ripple) on the two leads of the thermistor R, thereby improving the anti-interference capability of temperature detection.

[0037] Optionally, the differential amplification unit 11 has a magnification factor of 10-12 times.

[0038] Specifically, the amplification factor of the differential amplifier unit 11 is set to 10-12 times. This gain range is optimized based on the matching relationship between the output voltage swing of a conventional thermistor across the entire temperature range and the full-scale input voltage of the ADC. If the gain is less than 10 times, the amplified signal will be too small, failing to fully utilize the ADC's resolution and leading to increased temperature quantization error; if the gain is greater than 12 times, the output signal of the thermistor at the highest temperature may exceed the ADC's full-scale input, causing signal clipping distortion.

[0039] In one specific embodiment, the ratio of R3 / R4 is matched with that of R6 / R5 to achieve a gain range of 10-12 times. For example, R6 = 100kΩ, R5 = 10kΩ (gain of 10 times), or R6 = 110kΩ, R5 = 10kΩ (gain of 11 times), or R6 = 120kΩ, R5 = 10kΩ (gain of 12 times). By matching the ratio of R3 / R4 to R6 / R5, the common-mode rejection capability of the differential amplifier across the thermistor R is optimized, while the precise gain setting ensures that the amplified voltage signal is adapted to the optimal input range of the subsequent analog-to-digital converter (ADC).

[0040] Optionally, the temperature drift compensation range of the temperature drift correction module 20 is -40℃ to 125℃.

[0041] Specifically, the temperature drift compensation range of the temperature drift correction module 20 is set to -40℃ to 125℃. This range covers most of the operating temperature boundaries of automotive electronics, industrial control, and outdoor equipment. Within this range, the temperature drift correction module 20 uses its internal temperature drift sensing unit 22 (such as the first diode D1) with negative temperature characteristics to sense changes in ambient temperature in real time, and dynamically adjusts the output current of the constant current source U1 through the current correction unit 23, so that the output current increases with the temperature, thereby accurately offsetting the decrease in resistance of the thermistor R (NTC type) caused by the temperature increase. After compensation, the voltage fluctuation across the thermistor R is compressed within a preset error band (e.g., ±0.1%), ensuring that the temperature output module 10 can stably and linearly calculate the ambient temperature across the entire temperature range.

[0042] Optionally, the thermistor R is a two-wire platinum resistance thermometer.

[0043] Specifically, the thermistor R is a two-wire platinum resistance thermometer. Platinum resistance thermometers offer advantages such as high accuracy, good long-term stability, and a wide temperature range (typically -50℃ to 500℃). While the lead resistance of a two-wire platinum resistance thermometer may introduce measurement errors, this error is negligible because the circuit uses a differential amplifier unit 11 to extract the voltage difference, and the lead resistance of the platinum resistance thermometer is typically small (on the order of 0.1Ω). By selecting a two-wire platinum resistance thermometer, the application range of this temperature detection circuit can be extended to industrial scenarios requiring higher accuracy and a wider temperature range.

[0044] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A temperature detection circuit, characterized in that, include: A constant current source is used to output a constant current. A thermistor, electrically connected to the constant current source, is used to sense the ambient temperature and generate a corresponding change in resistance. A temperature output module, electrically connected to the thermistor, is used to calculate the ambient temperature based on the voltage difference across the thermistor. The temperature drift correction module is electrically connected to the constant current source and the thermistor respectively. The temperature drift correction module is in the same environment as the thermistor and has drift characteristics that are opposite to the temperature drift trend of the thermistor. The temperature drift correction module is used to adjust the magnitude of the constant current based on the temperature drift change of the thermistor itself, so that the output current of the constant current source has a current drift opposite to the temperature drift of the thermistor, thereby offsetting the inherent resistance temperature drift of the thermistor itself.

2. The temperature detection circuit according to claim 1, characterized in that, The temperature drift correction module includes: Reference cell, used to generate a constant base control current; The temperature drift sensing unit is located in the same temperature field as the thermistor and has a negative temperature characteristic that the voltage drop across its terminals decreases as the temperature increases. The current correction unit is electrically connected to the reference unit, the temperature drift sensing unit, and the driving terminal of the constant current source, respectively, and is used to generate a correction current based on the voltage drop generated by the temperature drift sensing unit as the temperature changes. The base control current and the correction current are superimposed to form a total control current to control the output current of the constant current source.

3. The temperature detection circuit according to claim 1, characterized in that, The temperature output module includes: A differential amplifier unit, electrically connected to the thermistor, is used to acquire and amplify the voltage difference across the thermistor. An analog-to-digital converter, electrically connected to the differential amplifier unit, is used to convert the voltage difference across the thermistor into the ambient temperature based on a preset conversion rule.

4. The temperature detection circuit according to claim 3, characterized in that, The temperature output module also includes a nonlinear correction unit, which is electrically connected to the analog-to-digital conversion unit and is used to perform nonlinear correction on the signal output by the analog-to-digital conversion unit to compensate for the resistance-temperature nonlinearity of the thermistor.

5. The temperature detection circuit according to claim 2, characterized in that, The constant current source includes an input terminal, an output terminal, and a control terminal; The input terminal of the constant current source is electrically connected to the reference power supply; The output terminal of the constant current source is electrically connected to the thermistor. The control terminal of the constant current source is electrically connected to the output terminal of the constant current source via the reference unit.

6. The temperature detection circuit according to claim 5, characterized in that, The reference unit includes a first resistor; The temperature drift sensing unit includes a first diode; The current correction unit includes a second resistor; The control terminal of the constant current source is electrically connected to the output terminal of the constant current source via the first resistor; The anode of the first diode is electrically connected to the output terminal of the constant current source, and the cathode is electrically connected to the thermistor; The second resistor is electrically connected to the control terminal of the constant current source and the cathode of the first diode, respectively.

7. The temperature detection circuit according to claim 3, characterized in that, The differential amplifier unit includes an operational amplifier; the analog-to-digital converter unit includes an analog-to-digital converter, a third resistor, a fourth resistor, a fifth resistor, and a sixth resistor. The non-inverting input terminal of the operational amplifier is electrically connected to the first terminal of the thermistor through the third resistor, and grounded through the fourth resistor. The inverting input terminal of the operational amplifier is electrically connected to the second terminal of the thermistor through the fifth resistor and grounded. The output terminal of the operational amplifier is electrically connected to the inverting input terminal of the operational amplifier through the sixth resistor; The analog-to-digital converter is electrically connected to the output of the operational amplifier.

8. The temperature detection circuit according to claim 3, characterized in that, The differential amplification unit has a magnification factor of 10-12 times.

9. The temperature detection circuit according to claim 1, characterized in that, The temperature drift correction module has a temperature drift compensation range of -40℃ to 125℃.

10. The temperature detection circuit according to claim 1, characterized in that, The thermistor is a two-wire platinum resistance thermometer.

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