Temperature protection circuit, high-voltage integrated circuit and driving chip

Abstract

The invention discloses a temperature protection circuit, a high-voltage integrated circuit and a driving chip, the temperature protection circuit comprises a temperature detection unit, a reference voltage unit and a hysteresis comparison unit, the temperature detection unit is used for obtaining temperature change conditions and outputting real-time voltage corresponding to the temperature to a first input end of the hysteresis comparison unit; the reference voltage unit is used for generating a reference voltage with a zero temperature coefficient to a second input end of the hysteresis comparison unit; the hysteresis comparison unit is used for comparing the real-time voltage with the reference voltage and outputting a temperature protection signal corresponding to the temperature according to a comparison result; according to the temperature protection circuit disclosed by the invention, the hysteresis comparison unit can output the temperature protection signal corresponding to the temperature by comparing the real-time voltage output by the temperature detection unit with the reference voltage output by the reference voltage unit, so that the sensitivity of temperature protection is improved, and error protection caused by temperature fluctuation can be effectively avoided; and the reliability and the stability of the circuit during working are enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature detection circuit design, and in particular to a temperature protection circuit, a high-voltage integrated circuit and a driving chip. Background Art

[0002] Temperature detection technology is crucial for power electronic devices. With the rapid development of science and technology and industry, the replacement speed of power electronic devices is accelerating, and users' requirements for equipment performance are also increasing. In this context, on-chip temperature detection technology is a key component of monolithic integrated intelligent power driver chips, and its accuracy has a decisive impact on the efficiency and stability of the application system in actual operation.

[0003] In order to achieve the design goals of high precision, low energy consumption and easy integration, the research and development of temperature detection modules is continuously optimized, especially in the high-voltage integrated intelligent drive chip HVIC. Key parts such as high-voltage level and pulse generation circuits will heat up rapidly under abnormal conditions. If the on-chip temperature detection module cannot accurately output temperature information, that is, there is a large error between the output detection temperature and the actual temperature, the microcontroller may perform improper operations after receiving the wrong temperature signal; this will not only reduce the system's operating efficiency, but may also delay the adoption of protective measures, resulting in continuous accumulation of heat, seriously threatening the reliability of the system and the safety of the chip, and may eventually cause chip damage.

[0004] It can be seen that the existing technology still needs further optimization and enhancement in improving the accuracy and stability of chip temperature monitoring. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a temperature protection circuit, which can not only improve the sensitivity of temperature protection, but also effectively avoid false protection caused by temperature fluctuations, so as to enhance the reliability and stability of the circuit during operation.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A temperature protection circuit comprises a temperature detection unit, a reference voltage unit and a hysteresis comparison unit, wherein the temperature detection unit is used to obtain temperature changes and output a real-time voltage corresponding to the temperature to a first input terminal of the hysteresis comparison unit; the reference voltage unit is used to generate a reference voltage with a zero temperature coefficient to a second input terminal of the hysteresis comparison unit; the hysteresis comparison unit is used to compare the real-time voltage and the reference voltage, and output a temperature protection signal corresponding to the temperature according to the comparison result.

[0008] In the temperature protection circuit, the temperature detection unit includes a current generating part, a current copying part and a ratio adjustment part, one end of the current generating part and one end of the current copying part are respectively used to connect to an external power supply device, the gate end of the current generating part is connected to the gate end of the current copying part, the gate end of the ratio adjustment part is connected to the other end of the current copying part, the other end of the current generating part and the source end of the ratio adjustment part are respectively grounded; the output end of the current copying part is connected to the first input end of the hysteresis comparison unit.

[0009] In the temperature protection circuit, the current generating unit includes a first PMOS tube PM1 and a first NMOS tube NM1, the current copying unit includes a second PMOS tube PM2 and a second NMOS tube NM2, and the ratio adjusting unit includes a third NMOS tube NM3; the source of the first PMOS tube and the source of the second PMOS tube are respectively used to connect to an external power supply device, the drain of the first PMOS tube PM1 is connected to the drain of the first NMOS tube NM1, and the drain of the second PMOS tube PM2 is connected to the drain of the second NMOS tube NM2 and the first input end of the hysteresis comparison unit; the gate of the first PMOS tube PM1 is respectively connected to the gate of the second PMOS tube PM2, the gate of the first NMOS tube NM1 and the gate of the second NMOS tube NM2; the source of the second NMOS tube NM2 is respectively connected to the gate and drain of the third NMOS tube NM; the source of the first NMOS tube NM1 and the source of the third NMOS tube NM3 are respectively grounded.

[0010] In the temperature protection circuit, the reference voltage unit includes a voltage generating part, a positive voltage part and a negative voltage part, one end of the voltage generating part and one end of the positive voltage part are respectively used to connect to an external power supply device, the gate end of the voltage generating part is connected to the gate end of the positive voltage part, and the negative voltage part is respectively connected to the voltage generating part and the positive voltage part; the output end of the positive voltage part is connected to the second input end of the hysteresis comparison unit.

[0011] In the temperature protection circuit, the voltage generating unit includes a first field effect transistor M1, a fourth field effect transistor M4 and a first transistor Q1, and the positive voltage unit includes a second field effect transistor M2, a third field effect transistor M3, a fifth field effect transistor M5, a first resistor R1, a second resistor R2 and a second transistor Q2; the source of the first field effect transistor M1, the source of the second field effect transistor M2 and the source of the third field effect transistor M3 are respectively used to connect to an external power supply device, the drain of the first field effect transistor M1 is respectively connected to the drain and gate of the fourth field effect transistor M4 and the gate of the fifth field effect transistor M5, the source of the fourth field effect transistor M4 is connected to the collector of the first transistor Q1; the second field effect transistor M2 is connected to the collector of the first transistor Q1, and the source of the second field effect transistor M3 is connected to the collector of the first transistor Q1. The gate and drain of the field effect transistor M2 are respectively connected to the gate of the first field effect transistor M1, the drain of the fifth field effect transistor M5 and the gate of the third field effect transistor M3; the source of the fifth field effect transistor M5 is connected to the collector of the second transistor Q2 through the first resistor R1; the base of the first transistor Q1 and the base of the second transistor Q2 are respectively connected to the base end of the negative voltage part; the drain of the third field effect transistor M3 and one end of the second resistor R2 are respectively connected to the second input end of the hysteresis comparison unit; the other end of the second resistor R2 is connected to the collector end of the negative voltage part; the emitter of the first transistor Q1 and the emitter of the second transistor Q2 are respectively grounded.

[0012] In the temperature protection circuit, the negative voltage part includes a third transistor Q3, the base of the third transistor Q3 is respectively connected to the base of the first transistor Q1 and the base of the second transistor Q2, the collector of the third transistor Q3 is connected to the other end of the second resistor R2, and the emitter of the third transistor Q3 is grounded.

[0013] In the temperature protection circuit, the third transistor Q3 is a bipolar transistor.

[0014] In the temperature protection circuit, the hysteresis comparison unit includes a hysteresis comparator, a first input end of the hysteresis comparator is connected to the output end of the temperature detection unit, and a second input end of the hysteresis comparator is connected to the output end of the reference voltage unit; the output end of the hysteresis comparator is used to compare the real-time voltage and the reference voltage, and output a temperature protection signal corresponding to the temperature according to the comparison result.

[0015] The present invention also accordingly provides a high-voltage integrated circuit, including a fault logic control circuit, a pulse circuit, an output circuit and the temperature protection circuit as described above, wherein the output end of the temperature protection circuit is connected to the input end of the fault logic control circuit, the output end of the fault logic control circuit is connected to the input end of the pulse circuit, the output end of the pulse circuit is connected to the input end of the output circuit, and the output end of the output circuit is used to output a driving pulse signal.

[0016] The present invention also provides a driver chip accordingly, on which the high-voltage integrated circuit as described above is integrated.

[0017] Beneficial effects:

[0018] The present invention provides a temperature protection circuit. Firstly, the temperature change is converted into a corresponding real-time voltage signal through a temperature detection unit, and the signal is stably output to the first input end of a hysteresis comparison unit, thereby ensuring the accuracy and real-time performance of the temperature data and providing a reliable basis for subsequent temperature protection actions. Secondly, a reference voltage with a zero temperature coefficient is generated through a reference voltage unit, and the signal is stably output to the second input end of the hysteresis comparison unit. Since the reference voltage has extremely high stability and is almost unaffected by changes in ambient temperature, measurement errors caused by temperature drift are effectively avoided. Finally, the real-time voltage is compared with the reference voltage through a hysteresis comparison unit. The hysteresis comparison unit has a built-in hysteresis characteristic and can effectively filter out short-term interference caused by temperature fluctuations to avoid the occurrence of false protection. This not only improves the sensitivity and response speed of the temperature protection, but also greatly enhances the overall reliability and stability of the circuit, thereby ensuring that the driver chip can operate safely and efficiently in various temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A circuit block diagram of the temperature protection circuit provided by the present invention;

[0020] Figure 2 A circuit schematic diagram of the temperature protection circuit provided by the present invention;

[0021] Figure 3 This is a circuit structure diagram of the high-voltage integrated circuit provided by the present invention.

[0022] Explanation of main component symbols: 1-temperature detection unit, 11-current generating unit, 12-current copying unit, 13-proportional adjustment unit, 2-reference voltage unit, 21-voltage generating unit, 22-positive voltage unit, 23-negative voltage unit, 3-hysteresis comparison unit, 4-fault logic control circuit, 5-pulse circuit, 6-output circuit. DETAILED DESCRIPTION

[0023] The present invention provides a temperature protection circuit, a high voltage integrated circuit and a driver chip. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below with reference to the accompanying drawings and examples.

[0024] In the description of the present invention, it should be understood that the terms "installation", "connection" and the like should be understood in a broad sense, and a person skilled in the art can understand the specific meanings of the above terms in the present invention according to specific circumstances.

[0025] See also Figure 1 and Figure 2 The present invention provides a temperature protection circuit, including a temperature detection unit 1, a reference voltage unit 2 and a hysteresis comparison unit 3, wherein the temperature detection unit 1 is used to obtain temperature changes and output a real-time voltage corresponding to the temperature to a first input terminal of the hysteresis comparison unit 3; the reference voltage unit 2 is used to generate a reference voltage with a zero temperature coefficient to a second input terminal of the hysteresis comparison unit 3; the hysteresis comparison unit 3 is used to compare the real-time voltage and the reference voltage, and output a temperature protection signal corresponding to the temperature according to the comparison result.

[0026] The temperature protection circuit disclosed in the present application, first, converts the temperature change into a corresponding real-time voltage signal through the temperature detection unit 1, and stably outputs it to the first input end of the hysteresis comparison unit 3, thereby ensuring the accuracy and real-time nature of the temperature data and providing a reliable basis for subsequent temperature protection actions; secondly, generates a reference voltage with a zero temperature coefficient through the reference voltage unit 2, and stably outputs it to the second input end of the hysteresis comparison unit 3. Since the reference voltage has extremely high stability and is almost unaffected by changes in ambient temperature, measurement errors caused by temperature drift are effectively avoided; finally, the real-time voltage is compared with the reference voltage through the hysteresis comparison unit 3. The hysteresis comparison unit 3 has a built-in hysteresis characteristic, which can effectively filter out short-term interference caused by temperature fluctuations and avoid the occurrence of false protection. It not only improves the sensitivity and response speed of the temperature protection, but also greatly enhances the overall reliability and stability of the circuit, ensuring that the driver chip can operate safely and efficiently in various temperature environments.

[0027] For further information, see Figure 1 and Figure 2The temperature detection unit 1 includes a current generating unit 11, a current copying unit 12 and a ratio adjustment unit 13. One end of the current generating unit 11 and one end of the current copying unit 12 are respectively used to connect to an external power supply device, the gate end of the current generating unit 11 is connected to the gate end of the current copying unit 12, the gate end of the ratio adjustment unit 13 is connected to the other end of the current copying unit 12, the other end of the current generating unit 11 and the source end of the ratio adjustment unit 13 are respectively grounded; the output end of the current copying unit 12 is connected to the first input end of the hysteresis comparison unit 3.

[0028] For further information, see Figure 2 The current generating unit 11 includes a first PMOS transistor PM1 and a first NMOS transistor NM1, the current copying unit 12 includes a second PMOS transistor PM2 and a second NMOS transistor NM2, and the ratio adjusting unit 13 includes a third NMOS transistor NM3; the source of the first PMOS transistor and the source of the second PMOS transistor are respectively used to connect to an external power supply device, the drain of the first PMOS transistor PM1 is connected to the drain of the first NMOS transistor NM1, the drain of the second PMOS transistor PM2 is connected to the drain of the second NMOS transistor NM2 and the first input end of the hysteresis comparison unit 3; the gate of the first PMOS transistor PM1 is respectively connected to the gate of the second PMOS transistor PM2, the gate of the first NMOS transistor NM1 and the gate of the second NMOS transistor NM2; the source of the second NMOS transistor NM2 is respectively connected to the gate and drain of the third NMOS transistor NM; the source of the first NMOS transistor NM1 and the source of the third NMOS transistor NM3 are respectively grounded.

[0029] In this embodiment, the temperature detection principle of the temperature detection unit 1 is designed based on the working characteristics of the NMOS transistor in the saturation region; specifically, when the channel length of the NMOS tube is large, the influence of the channel modulation effect can be effectively ignored. At this time, the drain-source current IDS flowing through the NMOS tube can be expressed by a clear formula, which involves the gate-source voltage VGS, the threshold voltage VTH and a series of process-related parameters. Since the two key parameters of the electron mobility μn and the threshold voltage VTH are negatively correlated with the temperature, this means that as the temperature increases, the values ​​of these two parameters will decrease accordingly. Therefore, by utilizing the characteristics of the NMOS tube, accurate temperature detection can be achieved; in the circuit design of the temperature detection unit 1, the NMOS The currents of NMOS tube 1, NM2 tube and NM3 tube are set to ID1 and ID2 respectively, and ensure that the two are equal; the precise control of the current is achieved through the current mirror composed of PM1 and PM2, and its function is to ensure the stability and consistency of the current; based on the working characteristics of the NMOS tube in the saturation region and the temperature dependence of the relevant physical parameters, it can be determined that there is a first-order linear positive proportional relationship between the output voltage VOUT and the temperature T, which shows that any change in the ambient temperature will cause the output voltage VOUT to change accordingly, and this change presents an obvious linear characteristic; it is based on this principle that when the working state of the high-voltage integrated circuit changes, VOUT can output a voltage value corresponding to the current temperature, thereby realizing accurate detection of the temperature.

[0030] For further information, see Figure 1 and Figure 2 The reference voltage unit 2 includes a voltage generating unit 21, a positive voltage unit 22 and a negative voltage unit 23. One end of the voltage generating unit 21 and one end of the positive voltage unit 22 are respectively used to connect to an external power supply device. The gate end of the voltage generating unit 21 is connected to the gate end of the positive voltage unit 22. The negative voltage unit 23 is respectively connected to the voltage generating unit 21 and the positive voltage unit 22. The output end of the positive voltage unit 22 is connected to the second input end of the hysteresis comparison unit 3.

[0031] For further information, see Figure 2The voltage generating unit 21 includes a first field effect transistor M1, a fourth field effect transistor M4 and a first transistor Q1, and the positive voltage unit 22 includes a second field effect transistor M2, a third field effect transistor M3, a fifth field effect transistor M5, a first resistor R1, a second resistor R2 and a second transistor Q2; the source of the first field effect transistor M1, the source of the second field effect transistor M2 and the source of the third field effect transistor M3 are respectively used to connect to an external power supply device, the drain of the first field effect transistor M1 is respectively connected to the drain and gate of the fourth field effect transistor M4 and the gate of the fifth field effect transistor M5, and the source of the fourth field effect transistor M4 is connected to the collector of the first transistor Q1; the second field effect transistor M2 The gate and drain of the first field effect transistor M1 are respectively connected to the gate of the first field effect transistor M1, the drain of the fifth field effect transistor M5 and the gate of the third field effect transistor M3; the source of the fifth field effect transistor M5 is connected to the collector of the second transistor Q2 through the first resistor R1; the base of the first transistor Q1 and the base of the second transistor Q2 are respectively connected to the base end of the negative voltage part 23; the drain of the third field effect transistor M3 and one end of the second resistor R2 are respectively connected to the second input end of the hysteresis comparison unit 3; the other end of the second resistor R2 is connected to the collector end of the negative voltage part 23; the emitter of the first transistor Q1 and the emitter of the second transistor Q2 are respectively grounded.

[0032] For further information, see Figure 2 The negative voltage unit 23 includes a third transistor Q3, the base of the third transistor Q3 is respectively connected to the base of the first transistor Q1 and the base of the second transistor Q2, the collector of the third transistor Q3 is connected to the other end of the second resistor R2, and the emitter of the third transistor Q3 is grounded; the third transistor Q3 is a bipolar transistor.

[0033] In this embodiment, the first transistor Q1 and the second transistor Q2 are also bipolar transistors.

[0034] In the present embodiment, the reference voltage unit 2 is a voltage reference circuit of a current mirror structure. The core idea of ​​the current mirror structure is to generate equipotentials through precise current replication technology, thereby ensuring the stability and reliability of the circuit. In the circuit design of the reference voltage unit 2, M1 and M2, as proportional current mirrors, have exactly the same size and characteristics, so the currents flowing through them are also exactly the same. Similarly, since M4 and M5 have the same current and the same size, their source potentials are also exactly the same, that is, VX=VY. Since VX=VY, the voltage drop on the first resistor R1 is precisely controlled within the range of VBE(Q1)-VBE(Q2). This voltage drop generates a stable PTAT current on the first resistor R1. After the PTAT current is mirrored, a corresponding PTAT voltage is generated on the second resistor R2. In this process, In the process, the base-emitter voltage difference VBE of the third transistor Q3 shows a negative temperature coefficient characteristic, that is, it decreases with the increase of temperature; because the third transistor Q3 is a bipolar device BJT, its base-emitter voltage VBE is inversely proportional to the absolute temperature, that is, it will show a CTAT characteristic; according to the classic PN junction current formula, it can be derived that VBE=VTln(IC / IS), where VT is the thermal voltage, IC and IS are functions of temperature T, it can be seen that VBE changes with the change of temperature and has a negative temperature coefficient; by cleverly combining the voltages with positive temperature coefficient and negative temperature coefficient, the reference voltage unit 2 finally outputs a reference voltage VREF with a zero temperature coefficient. This reference voltage VREF is not only stable and reliable, but also can maintain a high degree of consistency when the temperature changes, providing a solid voltage foundation for the temperature protection circuit.

[0035] For further information, see Figure 2 The hysteresis comparison unit 3 includes a hysteresis comparator, a first input end of the hysteresis comparator is connected to the output end of the temperature detection unit 1, and a second input end of the hysteresis comparator is connected to the output end of the reference voltage unit 2; the output end of the hysteresis comparator is used to compare the real-time voltage and the reference voltage, and output a temperature protection signal corresponding to the temperature according to the comparison result.

[0036] In this embodiment, the hysteresis comparator has a hysteresis characteristic, which means that when the input signal changes, there is a hysteresis interval for the change of the output state, that is, the input signal needs to change to exceed a certain interval before the change of the output state is triggered; this characteristic is realized through an internal positive feedback mechanism, which can resist external interference to a certain extent and maintain the stable output of the circuit; in the temperature protection circuit, the hysteresis comparator is used to monitor the temperature signal, and the temperature signal is first input into the hysteresis comparator through the temperature detection unit 1, and the comparator has two threshold voltages: a positive threshold voltage and a negative threshold voltage; when the temperature signal exceeds the positive threshold voltage, the circuit outputs a protection signal to trigger the protection mechanism to prevent the chip or device from being damaged due to overheating; and when the temperature signal drops below the negative threshold voltage, the circuit will release the protection signal and allow the device to resume normal operation; due to the existence of the hysteresis characteristic, even if the temperature signal fluctuates between the positive threshold voltage and the negative threshold voltage, the output state of the circuit will remain stable, and the protection mechanism will not be frequently triggered due to slight temperature changes, which can not only reduce the malfunction of the circuit, but also improve the stability and reliability of the temperature protection circuit when it is working.

[0037] See also Figure 3 The present invention also provides a high-voltage integrated circuit accordingly, including a fault logic control circuit 4, a pulse circuit 5, an output circuit 6 and the temperature protection circuit as described above, wherein the output end of the temperature protection circuit is connected to the input end of the fault logic control circuit 4, the output end of the fault logic control circuit 4 is connected to the input end of the pulse circuit 5, the output end of the pulse circuit 5 is connected to the input end of the output circuit 6, and the output end of the output circuit 6 is used to output a driving pulse signal.

[0038] The present invention also provides a driver chip accordingly, on which the high-voltage integrated circuit as described above is integrated.

[0039] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the present invention.

Claims

1. A temperature protection circuit, characterized in that: It includes a temperature detection unit, a reference voltage unit and a hysteresis comparison unit. The temperature detection unit is used to obtain temperature changes and output a real-time voltage corresponding to the temperature to the first input end of the hysteresis comparison unit; the reference voltage unit is used to generate a reference voltage with a zero temperature coefficient to the second input end of the hysteresis comparison unit; the hysteresis comparison unit is used to compare the real-time voltage and the reference voltage, and output a temperature protection signal corresponding to the temperature according to the comparison result.

2. A temperature protection circuit according to claim 1, characterized in that: The temperature detection unit includes a current generating unit, a current copying unit and a ratio adjustment unit. One end of the current generating unit and one end of the current copying unit are respectively used to connect to an external power supply device, the gate end of the current generating unit is connected to the gate end of the current copying unit, the gate end of the ratio adjustment unit is connected to the other end of the current copying unit, the other end of the current generating unit and the source end of the ratio adjustment unit are respectively grounded; the output end of the current copying unit is connected to the first input end of the hysteresis comparison unit.

3. A temperature protection circuit according to claim 2, characterized in that: The current generating unit includes a first PMOS tube PM1 and a first NMOS tube NM1, the current copying unit includes a second PMOS tube PM2 and a second NMOS tube NM2, and the ratio adjusting unit includes a third NMOS tube NM3; the source of the first PMOS tube and the source of the second PMOS tube are respectively used to connect to an external power supply device, the drain of the first PMOS tube PM1 is connected to the drain of the first NMOS tube NM1, and the drain of the second PMOS tube PM2 is connected to the drain of the second NMOS tube NM2 and the first input end of the hysteresis comparison unit; the gate of the first PMOS tube PM1 is respectively connected to the gate of the second PMOS tube PM2, the gate of the first NMOS tube NM1 and the gate of the second NMOS tube NM2; the source of the second NMOS tube NM2 is respectively connected to the gate and drain of the third NMOS tube NM; the source of the first NMOS tube NM1 and the source of the third NMOS tube NM3 are respectively grounded.

4. A temperature protection circuit according to claim 1, characterized in that: The reference voltage unit includes a voltage generating unit, a positive voltage unit and a negative voltage unit, one end of the voltage generating unit and one end of the positive voltage unit are respectively used to connect to an external power supply device, the gate end of the voltage generating unit is connected to the gate end of the positive voltage unit, and the negative voltage unit is respectively connected to the voltage generating unit and the positive voltage unit; the output end of the positive voltage unit is connected to the second input end of the hysteresis comparison unit.

5. A temperature protection circuit according to claim 4, characterized in that: The voltage generating unit includes a first field effect transistor M1, a fourth field effect transistor M4 and a first transistor Q1, and the positive voltage unit includes a second field effect transistor M2, a third field effect transistor M3, a fifth field effect transistor M5, a first resistor R1, a second resistor R2 and a second transistor Q2; the source of the first field effect transistor M1, the source of the second field effect transistor M2 and the source of the third field effect transistor M3 are respectively used to connect to an external power supply device, the drain of the first field effect transistor M1 is respectively connected to the drain and gate of the fourth field effect transistor M4 and the gate of the fifth field effect transistor M5, and the source of the fourth field effect transistor M4 is connected to the collector of the first transistor Q1; the second field effect transistor M2 The gate and drain of the fifth field effect transistor M5 are respectively connected to the gate of the first field effect transistor M1, the drain of the fifth field effect transistor M5 and the gate of the third field effect transistor M3; the source of the fifth field effect transistor M5 is connected to the collector of the second transistor Q2 through the first resistor R1; the base of the first transistor Q1 and the base of the second transistor Q2 are respectively connected to the base end of the negative voltage part; the drain of the third field effect transistor M3 and one end of the second resistor R2 are respectively connected to the second input end of the hysteresis comparison unit; the other end of the second resistor R2 is connected to the collector end of the negative voltage part; the emitter of the first transistor Q1 and the emitter of the second transistor Q2 are respectively grounded.

6. A temperature protection circuit according to claim 5, characterized in that: The negative voltage unit includes a third transistor Q3, the base of the third transistor Q3 is respectively connected to the base of the first transistor Q1 and the base of the second transistor Q2, the collector of the third transistor Q3 is connected to the other end of the second resistor R2, and the emitter of the third transistor Q3 is grounded.

7. A temperature protection circuit according to claim 6, characterized in that: The third transistor Q3 is a bipolar transistor.

8. A temperature protection circuit according to claim 1, characterized in that: The hysteresis comparison unit includes a hysteresis comparator, a first input end of the hysteresis comparator is connected to the output end of the temperature detection unit, and a second input end of the hysteresis comparator is connected to the output end of the reference voltage unit; the output end of the hysteresis comparator is used to compare the real-time voltage and the reference voltage, and output a temperature protection signal corresponding to the temperature according to the comparison result.

9. A high voltage integrated circuit, characterized in that: It includes a fault logic control circuit, a pulse circuit, an output circuit and a temperature protection circuit as described in any one of claims 1 to 8, wherein the output end of the temperature protection circuit is connected to the input end of the fault logic control circuit, the output end of the fault logic control circuit is connected to the input end of the pulse circuit, the output end of the pulse circuit is connected to the input end of the output circuit, and the output end of the output circuit is used to output a driving pulse signal.

10. A driver chip, characterized in that: The driving chip is integrated with a high-voltage integrated circuit as claimed in claim 9.

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