Temperature monitoring circuit
By designing a temperature monitoring circuit that uses the constant current source and uses time -sharing sampling technology, the problem of high circuits and costs of multiple power devices in the existing technologies is solved, and the circuit simplification and miniaturization are achieved.
Patent Information
- Application Number
- CN202310919072.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-24
- Publication Date
- 2025-01-24
AI Technical Summary
When multiple power devices are connected in parallel, an additional constant current source and temperature monitoring circuit are needed to increase the PCB area and circuit complexity, and the cost is also increased accordingly, which is not conducive to product miniaturization.
Design a temperature monitoring circuit. Through a constant current source and a temperature sensing module, the signal control module is used to realize time-sharing sampling of the first temperature sensor and the second temperature sensor. The constant current source is shared, reducing circuit complexity and PCB area, and borrowing The existing voltage source simplifies the power supply structure.
The size of the temperature monitoring circuit is reduced, the structure is simplified, and the cost is reduced, which avoids the need for additional constant flow sources and temperature monitoring circuits when multiple power devices are connected in parallel, and promote the miniaturization of the product.
Smart Images
Figure CN119354358A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of circuits, and more particularly to temperature monitoring circuits. Background Art
[0002] In the field of power electronics, as power increases, more power devices (such as IGBTs, MOSFETs, etc.) need to be connected in parallel. Due to differences in power devices, location layout and other factors, the current flowing through each power device will be different, resulting in current imbalance, which in turn leads to inconsistent and random temperatures of the power devices. In order to ensure safe operation of the system and to identify possible faults as early as possible, each power device needs to be temperature monitored.
[0003] With the demand for miniaturization of power electronic products (such as motor controllers, power supplies, etc.), the internal circuit board space is getting smaller and smaller. As the degree of chip integration increases, the cost-effectiveness of multi-functional chips is obvious, so multi-functional chips are widely used.
[0004] At present, the isolation chip used to drive power devices has built-in constant current source in addition to driving and diagnostic functions. The constant current source is loaded on the temperature sampling diode or thermistor to form a voltage. The chip detects the voltage value and transmits it to the secondary control chip in isolation to complete the temperature measurement function. Existing driver chips such as BM6112FV-C or ACPL344JT have only one constant current source inside. When multiple power devices are connected in parallel, it is necessary to add additional constant current source and temperature monitoring circuit, or use new isolation sampling chips such as BM66002FV-C. This increases the PCB area and circuit complexity, while increasing costs and is not conducive to product miniaturization.
[0005] Therefore, a temperature monitoring circuit capable of reducing the size is required. Summary of the invention
[0006] One object of the present invention is to provide a temperature monitoring circuit capable of reducing the volume. Another object of the present invention is to provide a temperature monitoring circuit capable of simplifying the structure. Another object of the present invention is to provide a temperature monitoring circuit capable of reducing the cost.
[0007] One aspect of the present invention provides a temperature monitoring circuit, comprising: a constant current source for providing a constant current; a temperature sensing module, comprising a first temperature sensor and a second temperature sensor, wherein the temperature sensing module is configured to receive a constant current from the constant current source and provide an analog signal representing a temperature through the first temperature sensor and the second temperature sensor; and a signal control module, which is used to provide a control signal so that the constant current can flow through the first temperature sensor and the second temperature sensor in a time-sharing manner.
[0008] According to an embodiment of the present invention, the temperature sensing module also includes a first switch tube and a second switch tube, wherein the first switch tube is connected to the first temperature sensor, and the second switch tube is connected to the second temperature sensor; and the signal control module controls the time-sharing conduction of the first switch tube and the second switch tube through a control signal, wherein when the first switch tube is turned on, a constant current can flow through the first temperature sensor, and when the second switch tube is turned on, a constant current can flow through the second temperature sensor.
[0009] According to an embodiment of the present invention, the temperature monitoring circuit also includes: a voltage source, which is used to provide a negative first potential and a second potential of zero, wherein the voltage source is connected to a signal control module so that the first potential and the second potential serve as a low potential and a high potential of the signal control module respectively; and a potential conversion module, which is used to convert the potential range of the control signal of the signal control module from the second potential to the first potential to from a positive third potential to the second potential.
[0010] According to an embodiment of the present invention, a potential conversion module includes a first potential conversion submodule and a second potential conversion submodule, the first potential conversion submodule includes a third switch tube as an input stage and a fourth switch tube as an output stage, the third switch tube and the fourth switch tube are connected to each other, the third switch tube is connected to a signal control module to receive a control signal, and the fourth switch tube is connected to the first switch tube to provide the first switch tube with a control signal after potential conversion; and the second potential conversion submodule includes a fifth switch tube as an input stage and a sixth switch tube as an output stage, the fifth switch tube and the sixth switch tube are connected to each other, the fifth switch tube is connected to the signal control module to receive a control signal, and the sixth switch tube is connected to the second switch tube to provide the second switch tube with a control signal after potential conversion.
[0011] According to an embodiment of the present invention, the third switch tube, the fourth switch tube, the fifth switch tube and the sixth switch tube are bipolar transistors; the emitter of the third switch tube is connected to the first potential, the emitter of the fourth switch tube is connected to the second potential, and the collector of the fourth switch tube is connected to the third potential; and the emitter of the fifth switch tube is connected to the first potential, the emitter of the sixth switch tube is connected to the second potential, and the collector of the sixth switch tube is connected to the third potential.
[0012] According to an embodiment of the present invention, the temperature monitoring circuit also includes: an analog-to-digital conversion module, which is used to convert an analog signal representing the temperature received from the temperature sensing module into a digital signal; and a temperature calculation module, which is used to calculate the temperature measured by the first temperature sensor or the second temperature sensor based on the digital signal.
[0013] According to an embodiment of the present invention, the analog-to-digital conversion module and the constant current source are integrated in the driver, and the first potential and the second potential of the voltage source are connected to the driver.
[0014] According to an embodiment of the present invention, the first switching tube and the second switching tube are field effect transistors, the first end of the first temperature sensor is connected to a constant current source and the second end is connected to the drain of the first switching tube, the emitter of the fourth switching tube is connected to the gate of the first switching tube, and the source of the first switching tube is connected to the second potential; and the first end of the second temperature sensor is connected to the constant current source and the second end is connected to the drain of the second switching tube, the emitter of the sixth switching tube is connected to the gate of the second switching tube, and the source of the second switching tube is connected to the second potential.
[0015] According to an embodiment of the present invention, the first temperature sensor and the second temperature sensor are negative temperature coefficient thermistors.
[0016] According to an embodiment of the present invention, the signal control module includes a digital isolator.
[0017] Thus, the first temperature sensor and the second temperature sensor can share a constant current source, and through the control of the signal control module, the time-sharing sampling of the first temperature sensor and the second temperature sensor can be realized, so that there is no need to introduce a new constant current source, thereby reducing the circuit complexity and PCB area and reducing the cost. In addition, the signal control module (digital isolator) can borrow the existing voltage source with a negative potential as the reference potential (from a second potential of zero to a negative first potential), so there is no need to provide another voltage source separately, thereby simplifying the power supply structure. In addition, the potential conversion module can convert the reference potential of the control signal from a negative potential to a zero potential based on the on-off characteristics of the switch tube, so that the on-off of the first switch tube and the second switch tube can be normally controlled, and the temperature sensing module can work normally. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 is a schematic diagram of a temperature monitoring circuit according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION
[0019] Hereinafter, embodiments of the present invention are described with reference to the accompanying drawings. The following detailed description and the accompanying drawings are used to exemplarily illustrate the principles of the present invention, and the present invention is not limited to the preferred embodiments described. The scope of the present invention is defined by the claims. The present invention is now described in detail with reference to exemplary embodiments, and some embodiments are illustrated in the accompanying drawings. The following description is made with reference to the accompanying drawings, and unless otherwise indicated, the same reference numerals in different drawings represent the same or similar elements. The schemes described in the following exemplary embodiments do not represent all schemes of the present invention. On the contrary, these schemes are merely examples of systems and methods of various aspects of the present invention involved in the appended claims.
[0020] To solve the above technical problems, the present invention provides a temperature monitoring circuit. Below, exemplary embodiments of the present invention are described with reference to the accompanying drawings. It should be understood that the accompanying drawings only show certain embodiments of the present invention, and the scope of the present invention should be determined according to the claims.
[0021] Figure 1 is a schematic diagram of a temperature monitoring circuit according to an exemplary embodiment of the present invention. According to an embodiment of the present invention, the temperature monitoring circuit includes a constant current source, a voltage source, a temperature sensing module, a signal control module, a potential conversion module, an analog-to-digital conversion module and a temperature calculation module.
[0022] The constant current source is used to provide a constant current. In an exemplary embodiment, Figure 1 As shown, the constant current source is provided by the driver U1. Specifically, the driver U1 has a built-in constant current source and outputs a constant current through the pin TC. The driver U1 may be a gate driver chip. It should be understood that the driver U1 may also include other pins not shown in the figure.
[0023] The temperature sensing module is used to receive a constant current from a constant current source and provide an analog signal representing the temperature. Figure 1 As shown, the temperature sensing module includes a first temperature sensor R1, a second temperature sensor R2, a first switch tube Q1 and a second switch tube Q2.
[0024] In an exemplary embodiment, the first temperature sensor R1 and the second temperature sensor R2 are thermistors, in particular, negative temperature coefficient (NTC) thermistors. For example, the first temperature sensor R1 and the second temperature sensor R2 can be respectively arranged near a power device whose temperature needs to be monitored, so as to detect the temperature change of the corresponding power device. When a constant current source flows through the first temperature sensor R1 or the second temperature sensor R2, an analog signal representing the temperature can be provided.
[0025] In an exemplary embodiment, the first switch tube Q1 and the second switch tube Q2 may be field effect transistors, in particular metal oxide semiconductor field effect transistors (MOSFETs). More specifically, the first switch tube Q1 and the second switch tube Q2 may be N-channel MOSFETs.
[0026] In an exemplary embodiment, the first temperature sensor R1 has a first terminal connected to a constant current source of the driver U1 (pin TC of the driver U1), and a second terminal connected to the drain of the first switch Q1. The source of the first switch Q1 is connected to a second potential (described below).
[0027] In an exemplary embodiment, a first end of the second temperature sensor R2 is connected to a constant current source of the driver U1 (pin TC of the driver U1), and a second end is connected to a drain of the second switch tube Q2. A source of the second switch tube Q2 is connected to a second potential (described below).
[0028] The voltage source is used to provide a negative first potential (eg, -4V) and a zero second potential (GND). Figure 1 As shown, a first potential (eg, -4V) and a second potential (0V) of the voltage source are respectively connected to (pins VEE2 and GND2 of) the driver U1, providing a supply voltage (eg, from 0V to -4V) for the output side of the driver U1.
[0029] The signal control module is used to provide a control signal so that the constant current can flow through the first temperature sensor R1 and the second temperature sensor R2 in a time-sharing manner. Specifically, the signal control module can control the on and off of the first switch tube Q1 and the second switch tube Q2, thereby controlling the constant current to flow through the first temperature sensor R1 or the second temperature sensor R2 respectively. According to an embodiment of the present invention, Figure 1 As shown, the signal control module includes a digital isolator U2. The digital isolator U2 may be a digital isolation chip. The digital isolator U2 includes two output pins OUTA and OUTB. It should be understood that the digital isolator U2 may also include other pins not shown in the figure.
[0030] In an exemplary embodiment, the voltage source is connected to the signal control module so that the first potential (e.g., -4V) and the second potential (0V) are respectively used as the low potential and the high potential of the signal control module, that is, the signal control module uses the negative first potential (e.g., -4V) as the reference potential. Specifically, the first potential (e.g., -4V) and the second potential (0V) of the voltage source are respectively connected to the pins VCC2 and GND2 of the digital isolator U2 to provide a power supply voltage (e.g., from 0V to -4V) for the output side of the digital isolator U2. Thus, the digital isolator U2 can share the first potential and the second potential of the voltage source with the driver U1 to provide it with a power supply voltage, that is, borrow the voltage source of the driver U1, without having to set up another voltage source separately for the digital isolator U2.
[0031] When the digital isolator U2 uses the voltage source of the driver U1, since the potential range of the voltage source is from the second potential of zero to the negative first potential, for example, from 0V to -4V, the output signal of the digital isolator U2 also has a potential range from 0V to -4V. At the same time, since the reference potential of the first switch tube Q1 and the second switch tube Q2 is 0V, the control signal with a potential range of 0V to -4V cannot directly drive the first switch tube Q1 and the second switch tube Q2.
[0032] To this end, according to an embodiment of the present invention, a potential conversion module may also be provided to convert the potential range of the control signal of the signal control module from the second potential to the first potential (e.g., from 0 to -4V) to from the third potential to the second potential (e.g., from 15V to 0V). In an exemplary embodiment, the third potential is 15V.
[0033] In an exemplary embodiment, if Figure 1 As shown, the potential conversion module includes a first potential conversion submodule and a second potential conversion submodule.
[0034] The first potential conversion submodule includes a third switch tube Q3 as an input stage and a fourth switch tube Q4 as an output stage. In an exemplary embodiment, the third switch tube Q3 is a bipolar transistor, such as an NPN transistor; the fourth switch tube Q4 is a bipolar transistor, such as a PNP transistor. The third switch tube Q3 and the fourth switch tube Q4 are connected to each other. The third switch tube Q3 is connected to the signal control module (pin OUTA of the digital isolator U2) to receive a control signal, and the fourth switch tube Q4 is connected to the first switch tube Q1 to provide the first switch tube Q1 with a control signal converted by potential. In an exemplary embodiment, the emitter of the third switch tube Q3 is connected to the first potential, the emitter of the fourth switch tube Q4 is connected to the second potential, and the collector of the fourth switch tube Q4 is connected to the third potential. In addition, the first potential conversion submodule may also include resistors R3, R4, R5, R6 and R7.
[0035] Specifically, the output pin OUTA of the digital isolator U2 is connected to the first end of the resistor R3, and the second end of the resistor R3 is connected to the base of the third switch tube Q3. The first end of the resistor R4 is connected to the base of the third switch tube Q3, and the second end is connected to the emitter of the third switch tube Q3 and connected to the first potential (e.g., -4V). The first end of the resistor R5 is connected to the collector of the third switch tube Q3, and the second end is connected to the base of the fourth switch tube Q4. The first end of the resistor R6 is connected to the base of the fourth switch tube Q4, and the second end is connected to the collector of the fourth switch tube Q4 and connected to the third potential (e.g., 15V). The first end of the resistor R7 is connected to the emitter of the fourth switch tube Q4 and to the gate of the first switch tube Q1, and the second end is connected to the second potential (0V). The emitter of the fourth switch tube Q4 is also connected to the gate of the first switch tube Q1.
[0036] The second potential conversion submodule includes a fifth switch tube Q5 as an input stage and a sixth switch tube Q6 as an output stage. In an exemplary embodiment, the fifth switch tube Q5 is a bipolar transistor, such as an NPN transistor; the sixth switch tube Q6 is a bipolar transistor, such as a PNP transistor. The fifth switch tube Q5 and the sixth switch tube Q6 are connected to each other. The fifth switch tube Q5 is connected to the signal control module (pin OUTB of the digital isolator U2) to receive a control signal, and the sixth switch tube Q6 is connected to the second switch tube Q2 to provide a control signal converted by potential to the second switch tube Q2. In an exemplary embodiment, the emitter of the fifth switch tube Q5 is connected to the first potential, the emitter of the sixth switch tube Q6 is connected to the second potential, and the collector of the sixth switch tube Q6 is connected to the third potential. In addition, the first potential conversion submodule may also include resistors R8, R9, R10, R11 and R12.
[0037] Specifically, the output pin OUTA of the digital isolator U2 is connected to the first end of the resistor R8, and the second end of the resistor R8 is connected to the base of the fifth switch tube Q5. The first end of the resistor R9 is connected to the base of the fifth switch tube Q5, and the second end is connected to the emitter of the fifth switch tube Q5 and connected to the first potential (e.g., -4V). The first end of the resistor R10 is connected to the collector of the fifth switch tube Q5, and the second end is connected to the base of the sixth switch tube Q6. The first end of the resistor R11 is connected to the base of the sixth switch tube Q6, and the second end is connected to the collector of the sixth switch tube Q6 and connected to the third potential (e.g., 15V). The first end of the resistor R12 is connected to the emitter of the sixth switch tube Q6 and to the gate of the second switch tube Q2, and the second end is grounded and connected to the second potential (0V). The emitter of the sixth switch tube Q6 is also connected to the gate of the second switch tube Q2.
[0038] The analog-to-digital conversion module is used to convert the analog signal representing the temperature received from the temperature sensing module into a digital signal. In an exemplary embodiment, the analog-to-digital conversion module and the constant current source are both integrated in the driver U1.
[0039] The temperature calculation module is used to calculate the temperature measured by the first temperature sensor R1 or the second temperature sensor R2 according to the above digital signal. In an exemplary embodiment, the temperature calculation module can be set in the microprocessor MCU. In an exemplary embodiment, the pin SENSOR of the driver U1 can be connected to the interface GPIO1 of the microprocessor MCU, so that the converted digital signal can be sent to the microprocessor MCU for temperature calculation.
[0040] In an exemplary embodiment, the interface GPIO2 of the microprocessor MCU can be connected to the input pins INA and INB of the digital isolator U2 respectively. The microprocessor MCU can control the high and low levels of the input pins INA and INB of the digital isolator U2 under software control, so as to control the output pins OUTA and OUTB of the digital isolator U2 to output control signals.
[0041] The operation process of the temperature monitoring circuit according to the exemplary embodiment of the present invention will be described below with reference to the accompanying drawings.
[0042] When the signal control module is required to control and provide a control signal so that the constant current can flow through the first temperature sensor R1, the input pin INA of the digital isolator U2 is set to a high level and the input pin INB is set to a low level, so that the digital isolator U2 will provide the control signal to the first potential conversion submodule of the potential conversion module through the pin OUTA, wherein the potential range of the control signal is from the second potential (0V) to the first potential (e.g., -4V). The first potential conversion submodule will convert the potential range of the control signal (e.g., from 0V to -4V) to from the third potential (e.g., 15V) to the second potential (0V) by turning on and off the third switch tube Q3 and the fourth switch tube Q4. Afterwards, the control signal after potential conversion will turn on the first switch tube Q1, while the second switch tube Q2 will be in the off state, so that the constant current from the constant current source (pin TC of the driver chip U1) can flow through the first temperature sensor R1 to provide a corresponding analog signal representing the temperature. The analog-to-digital conversion module (driver U1) can convert the analog signal into a digital signal and send it to the temperature calculation module (microprocessor MCU). The temperature calculation module can calculate the temperature measured by the first temperature sensor R1 according to the digital signal.
[0043] When the signal control module is required to control and provide a control signal so that the constant current can flow through the second temperature sensor R2, the input pin INA of the digital isolator U2 is set to a low level and the input pin INB is set to a high level, so that the digital isolator U2 will provide the control signal to the second potential conversion submodule of the potential conversion module through the pin OUTB, wherein the potential range of the control signal is from the second potential (0V) to the first potential (e.g., -4V). The second potential conversion submodule will convert the potential range of the control signal (e.g., from 0V to -4V) to from the third potential (e.g., 15V) to the second potential (0V) by turning on and off the fifth switch tube Q5 and the sixth switch tube Q6. Afterwards, the control signal after potential conversion will turn on the second switch tube Q2, while the first switch tube Q1 will be in the off state, so that the constant current from the constant current source (pin TC of the driver chip U1) can flow through the second temperature sensor R2 to provide a corresponding analog signal representing the temperature. The analog-to-digital conversion module (driving chip U1) can convert the analog signal into a digital signal and send it to the temperature calculation module (microprocessor MCU). The temperature calculation module can calculate the temperature measured by the second temperature sensor R2 according to the digital signal.
[0044] Thus, the first temperature sensor and the second temperature sensor can share a constant current source, and through the control of the signal control module, the time-sharing sampling of the first temperature sensor and the second temperature sensor can be realized, so that there is no need to introduce a new constant current source, thereby reducing the circuit complexity and PCB area and reducing the cost. In addition, the signal control module (digital isolator) can borrow the existing voltage source with a negative potential as the reference potential (from a second potential of zero to a negative first potential), so there is no need to provide another voltage source separately, thereby simplifying the power supply structure. In addition, the potential conversion module can convert the reference potential of the control signal from a negative potential to a zero potential based on the on-off characteristics of the switch tube, so that the on-off of the first switch tube and the second switch tube can be normally controlled, and the temperature sensing module can work normally.
[0045] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the configuration and method of the above-described embodiments. On the contrary, the present invention is intended to cover various modifications and equivalent configurations. In addition, although the various elements and method steps of the disclosed invention are shown in various exemplary combinations and configurations, other combinations including more or less elements or methods also fall within the scope of the present invention.
[0046] Reference numerals list
[0047] U1 driver;
[0048] U2 digital isolator;
[0049] R1 first temperature sensor;
[0050] R2 second temperature sensor;
[0051] R3-R12 resistors;
[0052] Q1 first switch tube;
[0053] Q2 second switch tube;
[0054] Q3 the third switch tube;
[0055] Q4 the fourth switch tube;
[0056] Q5 is the fifth switch tube;
[0057] Q6 the sixth switch tube;
[0058] MCU microprocessor.
Claims
1. A temperature monitoring circuit, comprising: A constant current source, used for providing a constant current; A temperature sensing module, comprising a first temperature sensor (R1) and a second temperature sensor (R2), wherein the temperature sensing module is configured to receive the constant current from the constant current source and provide an analog signal representing the temperature through the first temperature sensor (R1) and the second temperature sensor (R2); and A signal control module is used to provide a control signal so that the constant current can flow through the first temperature sensor (R1) and the second temperature sensor (R2) in a time-sharing manner.
2. The temperature monitoring circuit according to claim 1, wherein: The temperature sensing module further comprises a first switch tube (Q1) and a second switch tube (Q2), wherein the first switch tube (Q1) is connected to the first temperature sensor (R1), and the second switch tube (Q2) is connected to the second temperature sensor (R2); and The signal control module controls the time-sharing conduction of the first switch tube (Q1) and the second switch tube (Q2) through the control signal, wherein when the first switch tube (Q1) is turned on, the constant current can flow through the first temperature sensor (R1), and when the second switch tube (Q2) is turned on, the constant current can flow through the second temperature sensor (R2).
3. The temperature monitoring circuit according to claim 2, further comprising: a voltage source for providing a negative first potential and a zero second potential, wherein the voltage source is connected to the signal control module so that the first potential and the second potential serve as a low potential and a high potential of the signal control module, respectively; and A potential conversion module is used to convert the potential range of the control signal of the signal control module from the second potential to the first potential to from a positive third potential to the second potential.
4. The temperature monitoring circuit according to claim 3, wherein: The potential conversion module includes a first potential conversion submodule and a second potential conversion submodule. The first potential conversion submodule comprises a third switch tube (Q3) as an input stage and a fourth switch tube (Q4) as an output stage, the third switch tube (Q3) and the fourth switch tube (Q4) are connected to each other, the third switch tube (Q3) is connected to the signal control module to receive the control signal, and the fourth switch tube (Q4) is connected to the first switch tube (Q1) to provide the first switch tube (Q1) with the control signal after potential conversion; and The second potential conversion submodule includes a fifth switch tube (Q5) as an input stage and a sixth switch tube (Q6) as an output stage, the fifth switch tube (Q5) and the sixth switch tube (Q6) are connected to each other, the fifth switch tube (Q5) is connected to the signal control module to receive the control signal, and the sixth switch tube (Q6) is connected to the second switch tube (Q2) to provide the control signal after potential conversion to the second switch tube (Q2).
5. The temperature monitoring circuit according to claim 4, wherein: The third switch tube (Q3), the fourth switch tube (Q4), the fifth switch tube (Q5) and the sixth switch tube (Q6) are bipolar transistors; The emitter of the third switch tube (Q3) is connected to the first potential, the emitter of the fourth switch tube (Q4) is connected to the second potential, and the collector of the fourth switch tube (Q4) is connected to the third potential; and The emitter of the fifth switch tube (Q5) is connected to the first potential, the emitter of the sixth switch tube (Q6) is connected to the second potential, and the collector of the sixth switch tube (Q6) is connected to the third potential.
6. The temperature monitoring circuit according to any one of claims 3 to 5, further comprising: An analog-to-digital conversion module, configured to convert the analog signal representing the temperature received from the temperature sensing module into a digital signal; and A temperature calculation module is used to calculate the temperature measured by the first temperature sensor (R1) or the second temperature sensor (R2) according to the digital signal.
7. The temperature monitoring circuit according to claim 6, wherein: The analog-to-digital conversion module and the constant current source are integrated in a driver (U1), and the first potential and the second potential of the voltage source are connected to the driver (U1).
8. The temperature monitoring circuit according to claim 4, wherein: The first switch tube (Q1) and the second switch tube (Q2) are field effect transistors. The first end of the first temperature sensor (R1) is connected to the constant current source and the second end is connected to the drain of the first switch tube (Q1), the emitter of the fourth switch tube (Q4) is connected to the gate of the first switch tube (Q1), and the source of the first switch tube (Q1) is connected to the second potential; and A first end of the second temperature sensor (R2) is connected to the constant current source and a second end is connected to the drain of the second switch tube (Q2), an emitter of the sixth switch tube (Q6) is connected to the gate of the second switch tube (Q2), and a source of the second switch tube (Q2) is connected to the second potential.
9. The temperature monitoring circuit according to any one of claims 1-5, 7-8, wherein: The first temperature sensor (R1) and the second temperature sensor (R2) are negative temperature coefficient thermistors.
10. The temperature monitoring circuit according to any one of claims 1-5, 7-8, wherein: The signal control module includes a digital isolator (U2).