Over-temperature protection circuit, power supply chip and electronic equipment

Abstract

The invention is suitable for the technical field of electronic circuits, and provides an over-temperature protection circuit, a power supply chip and electronic equipment. The over-temperature protection circuit comprises a band-gap reference module, a first current compensation module and a temperature detection module, the first current compensation module is connected with the band-gap reference module and the temperature detection module, and the band-gap reference module is connected with the temperature detection module. The first current compensation module, the band-gap reference module and the temperature detection module are used for being connected with the power supply module. The band-gap reference module is used for outputting a first voltage and a first current, and the first voltage is a voltage related to temperature. And the first current compensation module is used for outputting bias current to the temperature detection module according to the first current and the first level signal under a preset condition, and performing current compensation on the temperature detection module when the preset condition is changed. The temperature detection module is used for outputting a temperature detection signal and a first level signal according to the first voltage, the first current and the bias current.

Description

Technical Field

[0001] The present application belongs to the technical field of electronic circuits, and in particular relates to an over-temperature protection circuit, a power chip and an electronic device. Background Art

[0002] As the integration, power density and performance of modern electronic products continue to improve, the heat generated by circuits and components during operation is also gradually increasing. If the temperature of the device is too high, it may cause the performance of the components to deteriorate, shorten their lifespan, or even cause permanent damage, especially in high-power power management chips such as AC / DC (Alternating Current / Direct Current) converters and DC / DC (Direct Current / Direct Current) converters. Therefore, over-temperature protection circuits have become an indispensable part of many electronic products. They are mainly used to monitor the temperature of the device and take protective measures when the temperature is too high to ensure the reliability and safety of the system in high-temperature environments.

[0003] The traditional over-temperature protection circuit is mainly composed of IPTAT current (current positively correlated with temperature), resistor, comparator and field effect transistor. IPTAT current and resistor are used to output a voltage signal positively correlated with temperature, and the comparator is used to output a corresponding level signal according to the voltage signal related to temperature, so as to take protective measures when the temperature is too high. However, the resistance value of the resistor in the traditional over-temperature protection circuit is easily affected by the process conditions, resulting in inaccurate threshold of the over-temperature protection circuit, which in turn affects the stability and reliability of the system. Summary of the invention

[0004] The embodiments of the present application provide an over-temperature protection circuit, a power chip and an electronic device, which can solve the problem that the resistance value of the resistor in the traditional over-temperature protection circuit is easily affected by the process conditions, resulting in inaccurate threshold of the over-temperature protection circuit, thereby affecting the stability and reliability of the system.

[0005] In a first aspect, an embodiment of the present application provides an over-temperature protection circuit, including a bandgap reference module, a first current compensation module and a temperature detection module, wherein the first current compensation module is connected to the bandgap reference module and the temperature detection module respectively, the bandgap reference module is connected to the temperature detection module, and the first current compensation module, the bandgap reference module and the temperature detection module are all used to be connected to a power supply module;

[0006] The bandgap reference module is used to output a first voltage and a first current, wherein the first voltage is a voltage related to temperature; the first current compensation module is used to output a bias current to the temperature detection module according to the first current and a first level signal under preset conditions, and to perform current compensation on the temperature detection module when the preset conditions change; the temperature detection module is used to output a temperature detection signal and the first level signal according to the first voltage, the first current and the bias current.

[0007] In a possible implementation manner of the first aspect, the over-temperature protection circuit further includes a second current compensation module, the second current compensation module is connected to the first current compensation module, and the second current compensation module is used to be connected to the power supply module;

[0008] The second current compensation module is used to perform current compensation on the first current compensation module when the power supply voltage output by the power supply module changes.

[0009] In a possible implementation manner of the first aspect, the first current compensation module includes a first resistor, a second resistor, a third resistor, a first field effect transistor, a second field effect transistor, a third field effect transistor and a fourth field effect transistor, the gate of the first field effect transistor is connected to the bandgap reference module, the source of the first field effect transistor and the source of the second field effect transistor are both used to connect to the power supply module, the drain of the first field effect transistor is respectively connected to the gate of the third field effect transistor and the first end of the first resistor, the second end of the first resistor is respectively connected to the first end of the second resistor and the source of the fourth field effect transistor, the gate of the fourth field effect transistor is connected to the temperature detection module, the source of the third field effect transistor is respectively connected to the drain of the second field effect transistor, the gate of the second field effect transistor and the temperature detection module, the drain of the third field effect transistor is connected to the first end of the third resistor, and the drain of the fourth field effect transistor, the second end of the second resistor and the second end of the third resistor are all grounded.

[0010] In a possible implementation of the first aspect, the second current compensation module includes a fourth resistor, a fifth field effect transistor, a sixth field effect transistor and a seventh field effect transistor, the gate of the fifth field effect transistor is respectively connected to the gate of the sixth field effect transistor, the drain of the sixth field effect transistor and the source of the seventh field effect transistor, the source of the fifth field effect transistor and the source of the sixth field effect transistor are both used to connect to the power module, the drain of the fifth field effect transistor is connected to the first current compensation module, the gate of the seventh field effect transistor is respectively connected to the drain of the seventh field effect transistor and the first end of the fourth resistor, and the second end of the fourth resistor is grounded.

[0011] In a possible implementation manner of the first aspect, the bandgap reference module includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a first triode, a second triode, a third triode, a fourth triode, an operational amplifier, an eighth field effect transistor, a ninth field effect transistor, a tenth field effect transistor, an eleventh field effect transistor and a twelfth field effect transistor, the emitter of the first triode is respectively connected to the base of the second triode and the drain of the eighth field effect transistor, the emitter of the second triode is respectively connected to the first end of the fifth resistor, the drain of the ninth field effect transistor, the inverting input terminal of the operational amplifier and the temperature detection module, the non-inverting input terminal of the operational amplifier is respectively connected to the drain of the tenth field effect transistor, the first end of the sixth resistor and the first end of the eighth resistor, the second end of the eighth resistor is connected to the emitter of the third triode, the base of the third triode is respectively connected to the drain of the eleventh field effect transistor and The emitter of the fourth triode is connected, the drain of the twelfth field effect tube is connected to the first end of the seventh resistor, the output end of the operational amplifier is respectively connected to the gate of the eighth field effect tube, the gate of the ninth field effect tube, the gate of the tenth field effect tube, the gate of the eleventh field effect tube, the gate of the twelfth field effect tube, the first current compensation module and the temperature detection module, the source of the eighth field effect tube, the source of the ninth field effect tube, the source of the tenth field effect tube, the source of the eleventh field effect tube and the source of the twelfth field effect tube are all used to connect to the power supply module, the base of the first triode, the collector of the first triode, the collector of the second triode, the second end of the fifth resistor, the second end of the sixth resistor, the collector of the third triode, the base of the fourth triode, the collector of the fourth triode and the second end of the seventh resistor are all grounded.

[0012] In a possible implementation manner of the first aspect, the temperature detection module includes a temperature detection unit and a logic unit, the temperature detection unit is respectively connected to the bandgap reference module, the first current compensation module and the logic unit, the logic unit is connected to the first current compensation module, and the temperature detection unit is used to be connected to the power supply module;

[0013] The temperature detection unit is used to output a second level signal to the logic unit according to the first voltage, the first current and the bias current; the logic unit is used to output the temperature detection signal and the first level signal according to the second level signal.

[0014] In a possible implementation manner of the first aspect, the temperature detection unit includes a ninth resistor, a tenth resistor, a thirteenth field effect transistor, a fourteenth field effect transistor, a fifteenth field effect transistor, a sixteenth field effect transistor, and a seventeenth field effect transistor, the gate of the thirteenth field effect transistor is connected to the bandgap reference module, the drain of the thirteenth field effect transistor is connected to the first end of the ninth resistor, the source of the thirteenth field effect transistor is respectively connected to the gate of the fourteenth field effect transistor and the drain of the fifteenth field effect transistor, the source of the fourteenth field effect transistor is respectively connected to the gate of the fourteenth field effect transistor and the drain of the fifteenth field effect transistor, The drain of the transistor is connected to the gate of the seventeenth field effect transistor, the gate of the fifteenth field effect transistor is connected to the first current compensation module, the gate of the sixteenth field effect transistor is connected to the bandgap reference module, the source of the fifteenth field effect transistor, the source of the sixteenth field effect transistor and the source of the seventeenth field effect transistor are all used to connect to the power module, the drain of the seventeenth field effect transistor is respectively connected to the first end of the tenth resistor and the logic unit, and the second end of the ninth resistor, the drain of the fourteenth field effect transistor and the second end of the tenth resistor are all grounded.

[0015] In a possible implementation of the first aspect, the logic unit includes a Schmitt trigger and an inverter, the input end of the Schmitt trigger is connected to the temperature detection unit, the output end of the Schmitt trigger is respectively connected to the input end of the inverter and the first current compensation module, and the output end of the inverter is used to output the temperature detection signal.

[0016] In a second aspect, an embodiment of the present application provides a power chip, comprising the over-temperature protection circuit described in any one of the first aspects.

[0017] In a third aspect, an embodiment of the present application provides an electronic device, comprising the over-temperature protection circuit described in any one of the first aspects.

[0018] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0019] An embodiment of the present application provides an over-temperature protection circuit, including a bandgap reference module, a first current compensation module and a temperature detection module, wherein the first current compensation module is connected to the bandgap reference module and the temperature detection module respectively, and the bandgap reference module is connected to the temperature detection module, and the first current compensation module, the bandgap reference module and the temperature detection module are all used to connect to a power supply module.

[0020] The bandgap reference module is used to output a first voltage and a first current, and the first voltage is a voltage related to temperature. The first current compensation module is used to output a bias current to the temperature detection module according to the first current and the first level signal under preset conditions (i.e., under certain process conditions), and to perform current compensation on the temperature detection module when the preset conditions change (i.e., when the process conditions change). In this way, it can be ensured that the threshold of the over-temperature protection circuit does not shift, and the impact of the change in process conditions on the threshold of the over-temperature protection circuit is reduced. The temperature detection module is used to output a temperature detection signal and a first level signal according to the first voltage, the first current and the bias current. The temperature detection signal is used to instruct the system where the over-temperature protection circuit is located to perform corresponding operations. Since the first current compensation module performs current compensation on the temperature detection module when the process conditions change, the accuracy of the temperature detection signal output by the temperature detection module can be guaranteed, thereby improving the stability and reliability of the system where the over-temperature protection circuit is located.

[0021] In summary, the over-temperature protection circuit provided in the embodiment of the present application solves the problem that the resistance value of the resistor in the traditional over-temperature protection circuit is easily affected by the process conditions, resulting in inaccurate threshold of the over-temperature protection circuit, which in turn affects the stability and reliability of the system.

[0022] It can be understood that the beneficial effects of the second to third aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 This is the principle block diagram of the traditional over-temperature protection circuit;

[0025] Figure 2 is a principle block diagram of an over-temperature protection circuit provided in an embodiment of the present application;

[0026] Figure 3 is a principle block diagram of an over-temperature protection circuit provided in another embodiment of the present application;

[0027] Figure 4 is a principle block diagram of an over-temperature protection circuit provided in another embodiment of the present application;

[0028] Figure 5 Schematic diagram of circuit connection of an over-temperature protection circuit provided in one embodiment of the present application.

[0029] In the figure: 10, bandgap reference module; 20, first current compensation module; 30, temperature detection module; 31, temperature detection unit; 32, logic unit; 40, second current compensation module; 50, power supply module. DETAILED DESCRIPTION

[0030] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0031] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0032] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0033] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0034] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0035] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0036] In the field of chip design, the negative temperature characteristic of the emitter junction of a PNP transistor is often used to detect temperature. When the temperature exceeds the over-temperature protection threshold, the over-temperature protection circuit outputs an over-temperature protection signal, which is used to instruct the chip to shut down some or all circuits with higher power consumption. In order to prevent the over-temperature protection signal output by the over-temperature protection circuit from flipping multiple times at the over-temperature protection threshold, a hysteresis temperature protection threshold needs to be added. When the temperature drops to the hysteresis temperature protection threshold, the over-temperature protection circuit outputs a normal detection signal, which is used to instruct the chip to restart.

[0037] Traditional over-temperature protection circuits such as Figure 1 As shown, it is mainly composed of IPTAT current (current positively correlated with temperature), resistors R1 / R2, comparator COMP and field effect transistor MN1. The reference voltage VREF and comparator COMP constitute the temperature detection module. The IPTAT current and resistors R1 / R2 are used to output a voltage signal VA positively correlated with temperature. When the circuit is working normally, the VOUT output by the comparator COMP is a high-level signal, the field effect transistor MN1 is in the on state, and the resistor R2 is short-circuited. At this time, VA=IPTAT×R1, VA<VREF, and VOUT remains a high-level signal. When the temperature rises, the IPTAT current increases, causing VA to increase. When the temperature increases to the over-temperature protection threshold, VA=VREF. As the temperature continues to rise, VA>VREF, the VOUT output by the comparator COMP is flipped from a high-level signal to a low-level signal, the over-temperature protection is enabled, the chip stops working, and thermal shutdown is achieved. At the same time, the field effect transistor MN1 is turned off, and the resistor R2 is connected to the circuit, so that VA=IPTAT×(R1+R2). Due to the connection of resistor R2, when the temperature drops to the hysteresis temperature protection threshold, the output of comparator COMP will flip from a low-level signal to a high-level signal, enabling the chip to restart working. In this circuit, resistor R1 is used to set the over-temperature protection threshold, and resistor R2 is used to set the hysteresis temperature protection threshold, with a simple structure.

[0038] However, the resistance of the resistor in the traditional over-temperature protection circuit is easily affected by the process conditions, resulting in inaccurate thresholds of the over-temperature protection circuit (ie, the over-temperature protection threshold and the hysteresis temperature protection threshold), which in turn affects the stability and reliability of the system.

[0039] In view of the above problems, the present application provides an over-temperature protection circuit, such as Figure 2 As shown, the over-temperature protection circuit includes a bandgap reference module 10, a first current compensation module 20 and a temperature detection module 30. The first current compensation module 20 is connected to the bandgap reference module 10 and the temperature detection module 30 respectively. The bandgap reference module 10 is connected to the temperature detection module 30. The first current compensation module 20, the bandgap reference module 10 and the temperature detection module 30 are all used to connect to the power supply module 50.

[0040] Specifically, the bandgap reference module 10 is used to output a first voltage and a first current, and the first voltage is a voltage related to temperature. In the embodiment of the present application, the first voltage is a voltage that is negatively correlated with temperature. The first current compensation module 20 is used to output a bias current to the temperature detection module 30 according to the first current and the first level signal under preset conditions (i.e., under certain process conditions), and when the preset conditions change (i.e., when the process conditions change), the temperature detection module 30 is current compensated, so that the threshold of the over-temperature protection circuit is guaranteed not to be offset, and the influence of the change of process conditions on the threshold of the over-temperature protection circuit is reduced. The temperature detection module 30 is used to output a temperature detection signal OTP-OUT and a first level signal according to the first voltage, the first current and the bias current. The temperature detection signal OTP-OUT is used to indicate that the system where the over-temperature protection circuit is located performs corresponding operations. Since the first current compensation module 20 performs current compensation on the temperature detection module 30 when the process conditions change, the accuracy of the temperature detection signal OTP-OUT output by the temperature detection module 30 can be guaranteed, thereby improving the stability and reliability of the system where the over-temperature protection circuit is located.

[0041] In summary, the over-temperature protection circuit provided in the embodiment of the present application solves the problem that the resistance value of the resistor in the traditional over-temperature protection circuit is easily affected by the process conditions, resulting in inaccurate threshold of the over-temperature protection circuit, which in turn affects the stability and reliability of the system.

[0042] It should be noted that the first level signal is a hysteresis control signal.

[0043] In some embodiments, when the power supply voltage output by the power module 50 changes, the threshold of the over-temperature protection circuit may also shift. To solve this problem, Figure 3As shown, the over-temperature protection circuit provided in the embodiment of the present application further includes a second current compensation module 40 , which is connected to the first current compensation module 20 , and is also used to connect to the power supply module 50 .

[0044] Specifically, the second current compensation module 40 is used to perform current compensation on the first current compensation module 20 when the power supply voltage output by the power supply module 50 changes, thereby reducing the impact of the change in power supply voltage on the threshold of the over-temperature protection circuit, and improving the accuracy of the temperature detection signal OTP-OUT output by the over-temperature protection circuit, thereby improving the stability and reliability of the system in which the over-temperature protection circuit is located.

[0045] In some embodiments, Figure 5As shown, the bandgap reference module 10 includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first triode P1, a second triode P2, a third triode P3, a fourth triode P4, an operational amplifier AMP, an eighth field effect transistor M8, a ninth field effect transistor M9, a tenth field effect transistor M10, an eleventh field effect transistor M11 and a twelfth field effect transistor M12, the emitter of the first triode P1 is connected to the base of the second triode P2 and the drain of the eighth field effect transistor M8, respectively, and the The emitter of the second transistor P2 is respectively connected to the first end of the fifth resistor R5, the drain of the ninth field effect transistor M9, the inverting input end of the operational amplifier AMP and the temperature detection module 30, for outputting the first voltage VINN to the temperature detection module 30, the non-inverting input end of the operational amplifier AMP is respectively connected to the drain of the tenth field effect transistor M10, the first end of the sixth resistor R6 and the first end of the eighth resistor R8, the second end of the eighth resistor R8 is connected to the emitter of the third transistor P3, the base of the third transistor P3 is respectively connected to the drain of the eleventh field effect transistor M11 and the emitter of the fourth transistor P4, the drain of the twelfth field effect transistor M12 is connected to the first end of the seventh resistor R7, the output end of the operational amplifier AMP is respectively connected to the gate of the eighth field effect transistor M8, the gate of the ninth field effect transistor M9, the gate of the tenth field effect transistor M10, the gate of the eleventh field effect transistor M11, the gate of the twelfth field effect transistor M12, the first current compensation module 20 and the temperature detection module 30, the source of the eighth field effect transistor M8 is respectively connected to the gate of the twelfth field effect transistor M12. , the source of the ninth field effect transistor M9, the source of the tenth field effect transistor M10, the source of the eleventh field effect transistor M11 and the source of the twelfth field effect transistor M12 are all used to connect to the power module 50, and the base of the first triode P1, the collector of the first triode P1, the collector of the second triode P2, the second end of the fifth resistor R5, the second end of the sixth resistor R6, the collector of the third triode P3, the base of the fourth triode P4, the collector of the fourth triode P4 and the second end of the seventh resistor R7 are all grounded. Exemplarily, the first triode P1, the second triode P2, the third triode P3 and the fourth triode P4 are all PNP triodes. The eighth field effect transistor M8, the ninth field effect transistor M9, the tenth field effect transistor M10, the eleventh field effect transistor M11 and the twelfth field effect transistor M12 are all PMOS (positive channel Metal Oxide Semiconductor, P channel metal oxide semiconductor) tubes.

[0046] Specifically, the bandgap reference module 10 can generate a current with a near-zero temperature characteristic through the negative temperature characteristic of the emitter junction of the bipolar transistor and the positive temperature characteristic of the voltage difference between the emitter junctions of two identical transistors. The specific principle is: the voltage VINP at the non-inverting input terminal of the operational amplifier AMP = VR8 + VBE3 + VBE4, the voltage VINN at the inverting input terminal of the operational amplifier AMP = VBE2 + VBE1, wherein VR8 is the voltage on the eighth resistor R8, VBE3 is the emitter junction voltage of the third transistor P3, VBE4 is the emitter voltage of the fourth transistor P4, VBE2 is the emitter voltage of the first transistor P1, and VBE1 is the emitter junction voltage of the first transistor P1. By using the virtual short characteristic of the operational amplifier AMP to make the voltages of its two input terminals equal, VINP=VINN is obtained, so the voltage VR8 on the eighth resistor R8=VBE2+VBE1-VBE3+VBE4 can be obtained. Since the voltage difference between the emitter junctions of the two identical transistors presents a positive temperature characteristic, the voltage on the eighth resistor R8 is a positive temperature coefficient voltage, that is, the current flowing through the eighth resistor R8 is a positive temperature coefficient current. The voltage VR5 on the fifth resistor R5=VBE2+VBE1, since the emitter junction voltage of the PNP transistor presents a negative temperature characteristic, the voltage on the fifth resistor R5 is a negative temperature coefficient voltage, and the voltage on the fifth resistor R5 is the voltage VINN, which is the first voltage. Since the voltage on the fifth resistor R5 is equal to the voltage on the sixth resistor R6, and the resistance values ​​of the fifth resistor R5 and the sixth resistor R6 are equal, the current flowing through the sixth resistor R6 is a negative temperature coefficient current, and the drain current of the tenth field effect transistor M10 is the sum of the current flowing through the sixth resistor R6 and the current flowing through the eighth resistor R8. The zero temperature coefficient current on the branch where the tenth field effect transistor M10 is located is mirrored to the branch where the twelfth field effect transistor M12 is located through the current mirror, and outputs the first current to the first current compensation module 20 and the temperature detection module 30 respectively. The first current is a zero temperature coefficient current.

[0047] In some embodiments, Figure 4 As shown, the temperature detection module 30 includes a temperature detection unit 31 and a logic unit 32. The temperature detection unit 31 is respectively connected to the bandgap reference module 10, the first current compensation module 20 and the logic unit 32. The logic unit 32 is connected to the first current compensation module 20. The temperature detection unit 31 is used to connect to the power supply module 50.

[0048] Specifically, the temperature detection unit 31 is used to output a second level signal to the logic unit 32 according to the first voltage VINN, the first current and the bias current. The logic unit 32 is used to output the temperature detection signal OTP-OUT and the first level signal according to the second level signal.

[0049] In some embodiments, Figure 5 As shown, the temperature detection unit 31 includes a ninth resistor R9, a tenth resistor R10, a thirteenth field effect transistor M13, a fourteenth field effect transistor M14, a fifteenth field effect transistor M15, a sixteenth field effect transistor M16 and a seventeenth field effect transistor M17, the gate of the thirteenth field effect transistor M13 is connected to the bandgap reference module 10 for receiving the first voltage VINN, the drain of the thirteenth field effect transistor M13 is connected to the first end of the ninth resistor R9, the source of the thirteenth field effect transistor M13 is respectively connected to the gate of the fourteenth field effect transistor M14 and the drain of the fifteenth field effect transistor M15, the source of the fourteenth field effect transistor M14 is respectively connected to the sixteenth field effect transistor M16 and the drain of the fifteenth field effect transistor M15, the source of the fourteenth field effect transistor M14 is respectively connected to the gate of ... The drain of M16 is connected to the gate of the seventeenth field effect transistor M17, the gate of the fifteenth field effect transistor M15 is connected to the first current compensation module 20, the gate of the sixteenth field effect transistor M16 is connected to the bandgap reference module 10, the source of the fifteenth field effect transistor M15, the source of the sixteenth field effect transistor M16 and the source of the seventeenth field effect transistor M17 are all used to connect to the power module 50, the drain of the seventeenth field effect transistor M17 is respectively connected to the first end of the tenth resistor R10 and the logic unit 32, and is used to output the second level signal, the second end of the ninth resistor R9, the drain of the fourteenth field effect transistor M14 and the second end of the tenth resistor R10 are all grounded. Exemplarily, the thirteenth field effect transistor M13 and the fourteenth field effect transistor M14 are both NMOS (N-Metal-Oxide-Semiconductor, N-type metal-oxide-semiconductor) tubes, and the fifteenth field effect transistor M15, the sixteenth field effect transistor M16 and the seventeenth field effect transistor M17 are all PMOS tubes.

[0050] Specifically, the voltage at the gate of the thirteenth field effect transistor M13 is the first voltage VINN. Since the first voltage VINN is a negative temperature coefficient voltage, the higher the temperature, the lower the first voltage VINN. When the temperature is normal, the thirteenth field effect transistor M13 is turned on, and the current on the branch where the thirteenth field effect transistor M13 is located is the bias current output by the first current compensation module 20. Since the thirteenth field effect transistor M13 is turned on, the voltage VGN3 at the gate of the fourteenth field effect transistor M14 is low level, and the fourteenth field effect transistor M14 is disconnected. Since the sixteenth field effect transistor M16 is connected to the output end of the operational amplifier AMP in the bandgap reference module 10, the sixteenth field effect transistor M16 is turned on, and the current on the branch where the sixteenth field effect transistor M16 is located is the first current. Since the sixteenth field effect transistor M16 is turned on, the seventeenth field effect transistor M17 is disconnected, and the voltage of the tenth resistor R10 is low, that is, the second level signal output to the logic unit 32 is a low level signal. As the temperature increases, the first voltage VINN becomes lower and lower. When the temperature exceeds the over-temperature protection threshold, the first voltage VINN cannot control the thirteenth field effect transistor M13 to be turned on, so the thirteenth field effect transistor M13 is turned off. Since the thirteenth field effect transistor M13 is turned off, the voltage VGN3 at the gate of the fourteenth field effect transistor M14 is at a high level, and the fourteenth field effect transistor M14 is turned on. Since the fourteenth field effect transistor M14 is turned on, the seventeenth field effect transistor M17 is turned on, and the voltage on the tenth resistor R10 is high, that is, the second level signal output to the logic unit 32 is a high level signal.

[0051] In some embodiments, Figure 5 As shown, the logic unit 32 includes a Schmitt trigger SMIT and an inverter INV, the input end of the Schmitt trigger SMIT is connected to the temperature detection unit 31, and is used to receive the second level signal, the output end of the Schmitt trigger SMIT is respectively connected to the input end of the inverter INV and the first current compensation module 20, and is used to output the first level signal V-HYS to the first current compensation module 20 and the inverter INV, respectively, and the output end of the inverter INV is used to output the temperature detection signal OTP-OUT.

[0052] Specifically, the Schmitt trigger SMIT is equivalent to an inverter. When the input signal is a high-level signal, the Schmitt trigger SMIT outputs a low-level signal. When the input signal is a low-level signal, the Schmitt trigger SMIT outputs a high-level signal. It should be noted that the Schmitt trigger SMIT has two flip thresholds, which can play a hysteresis role and prevent the temperature detection signal OTP-OUT from flipping multiple times at the over-temperature protection threshold.

[0053] When the temperature is normal, the second level signal output by the temperature detection unit 31 is a low level signal. The second level signal outputs the first level signal V-HYS after passing through the Schmitt trigger SMIT. The first level signal V-HYS outputs the temperature detection signal OTP-OUT after passing through the inverter INV. At this time, the first level signal V-HYS is a high level signal, and the temperature detection signal OTP-OUT is a low level signal.

[0054] When the temperature exceeds the over-temperature protection threshold, the second level signal output by the temperature detection unit 31 is a high level signal, and the second level signal outputs the first level signal V-HYS after passing through the Schmitt trigger SMIT, and the first level signal V-HYS outputs the temperature detection signal OTP-OUT after passing through the inverter INV, at which time the first level signal V-HYS is a low level signal, and the temperature detection signal OTP-OUT is a high level signal. The high level signal is used to instruct the system where the over-temperature protection circuit is located to shut down some circuits with higher power consumption or all circuits.

[0055] In some embodiments, Figure 5 As shown, the first current compensation module 20 includes a first resistor R1, a second resistor R2, a third resistor R3, a first field effect transistor M1, a second field effect transistor M2, a third field effect transistor M3 and a fourth field effect transistor M4, the gate of the first field effect transistor M1 is connected to the bandgap reference module 10, the source of the first field effect transistor M1 and the source of the second field effect transistor M2 are both used to connect to the power module 50, the drain of the first field effect transistor M1 is respectively connected to the gate of the third field effect transistor M3 and the first end of the first resistor R1, and the second end of the first resistor R1 is connected to the gate of the third field effect transistor M3. The first and second FETs M1 and M2 are connected to the first and second FETs R2 and R2, respectively, and the gate of the fourth FET M4 is connected to the temperature detection module 30 for receiving the first level signal V-HYS. The source of the third FET M3 is connected to the drain of the second FET M2, the gate of the second FET M2 and the temperature detection module 30, respectively. The drain of the third FET M3 is connected to the first end of the third resistor R3. The drain of the fourth FET M4, the second end of the second resistor R2 and the second end of the third resistor R3 are all grounded. Exemplarily, the first FET M1 and the second FET M2 are both PMOS tubes, and the third FET M3 and the fourth FET M4 are both NMOS tubes.

[0056] Specifically, when the temperature is normal and under certain process conditions, the first level signal V-HYS is a high level signal, then the fourth field effect tube M4 is turned on, and the second resistor R2 is short-circuited. The current of the branch where the first field effect tube M1 is located is the first current, and the first current flows through the first resistor R1, generating a voltage VM3 on the first resistor R1, that is, the voltage at the gate of the third field effect tube M3 is VM3, then the third field effect tube M3 is turned on, and the current generated by the branch where the second field effect tube M2 is located is the bias current, and is mirrored to the fifteenth field effect tube M15 through the current mirror, providing a bias current for the temperature detection module 30. When the temperature exceeds the over-temperature protection threshold and under certain process conditions, the first level signal V-HYS is a low level signal, then the fourth field effect tube M4 is disconnected, and the second resistor R2 is connected in series with the first resistor R1, which will raise the voltage VM3 at the gate of the third field effect tube M3. When the voltage at the gate of the third field effect transistor M3 is raised, the current in the branch where the third field effect transistor M3 is located will increase, and then the current mirrored to the fifteenth field effect transistor M15 will also increase, thereby causing the voltage at the source of the thirteenth field effect transistor M13 to increase. If the thirteenth field effect transistor M13 is to be turned on again, the temperature needs to be lowered. Since the voltage at the source of the thirteenth field effect transistor M13 increases, a lower temperature is required to restart the thirteenth field effect transistor M13, thus forming a temperature hysteresis, which can prevent the temperature detection signal OTP-OUT from flipping multiple times at the over-temperature protection threshold.

[0057] When the process conditions change, the threshold of the thirteenth field effect transistor M13 and the resistance of the ninth resistor R9 in the temperature detection module 30 will change, resulting in the shift of the over-temperature protection threshold and the hysteresis temperature protection threshold. Since the threshold of the third field effect transistor M3 and the resistance of the third resistor R3 will also change with the change of the process conditions, that is, the current on the branch where the second field effect transistor M2 is located will also change, and then the current is mirrored to the branch where the thirteenth field effect transistor M13 is located through the current mirror, and the current on the branch where the thirteenth field effect transistor M13 is located is compensated to reduce the impact of the change of process conditions on the over-temperature protection threshold and the hysteresis temperature protection threshold.

[0058] In some embodiments, Figure 5As shown, the second current compensation module 40 includes a fourth resistor R4, a fifth field effect transistor M5, a sixth field effect transistor M6 and a seventh field effect transistor M7, the gate of the fifth field effect transistor M5 is respectively connected to the gate of the sixth field effect transistor M6, the drain of the sixth field effect transistor M6 and the source of the seventh field effect transistor M7, the source of the fifth field effect transistor M5 and the source of the sixth field effect transistor M6 are both used to connect to the power module 50, the drain of the fifth field effect transistor M5 is connected to the first current compensation module 20, the gate of the seventh field effect transistor M7 is respectively connected to the drain of the seventh field effect transistor M7 and the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is grounded. Exemplarily, the fifth field effect transistor M5, the sixth field effect transistor M6 and the seventh field effect transistor M7 are all PMOS tubes.

[0059] Specifically, when the power supply voltage output by the power supply module 50 changes, the gate voltage of the second field effect transistor M2 will also change, causing the voltage at the drain of the third field effect transistor M3 to change. Due to the channel length modulation effect, the current flowing through the third field effect transistor M3 will also change. At this time, due to the existence of the second current compensation module 40, when the power supply voltage changes, the current mirrored to the fifth field effect transistor M5 by the sixth field effect transistor M6 will also change, thereby compensating the current flowing through the third field effect transistor M3, preventing the change of the over-temperature protection threshold and the hysteresis temperature protection threshold due to the change of the power supply voltage.

[0060] In summary, the over-temperature protection circuit provided in the embodiment of the present application reduces the impact of changes in process conditions and changes in power supply voltage on the over-temperature protection threshold and the hysteresis temperature protection threshold, improves the accuracy of the temperature detection signal output by the over-temperature protection circuit, and ensures the reliability and safety of the system in which the over-temperature protection circuit is located under high temperature conditions.

[0061] The embodiment of the present application also provides a power chip, including the over-temperature protection circuit described above. Since the power chip provided by the embodiment of the present application includes the over-temperature protection circuit described above, the power chip provided by the embodiment of the present application reduces the influence of changes in process conditions and changes in power supply voltage on the over-temperature protection threshold and the hysteresis temperature protection threshold, thereby ensuring the reliability and safety of the power chip under high temperature conditions.

[0062] The embodiment of the present application also provides an electronic device, including the over-temperature protection circuit described above. Since the electronic device provided by the embodiment of the present application includes the over-temperature protection circuit described above, the electronic device provided by the embodiment of the present application reduces the influence of changes in process conditions and changes in power supply voltage on the over-temperature protection threshold and the hysteresis temperature protection threshold, thereby ensuring the reliability and safety of the electronic device under high temperature conditions.

[0063] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0064] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. An over-temperature protection circuit, characterized in that: It includes a bandgap reference module, a first current compensation module and a temperature detection module, wherein the first current compensation module is connected to the bandgap reference module and the temperature detection module respectively, the bandgap reference module is connected to the temperature detection module, and the first current compensation module, the bandgap reference module and the temperature detection module are all used to connect to a power supply module; The bandgap reference module is used to output a first voltage and a first current, wherein the first voltage is a voltage related to temperature; the first current compensation module is used to output a bias current to the temperature detection module according to the first current and a first level signal under preset conditions, and to perform current compensation on the temperature detection module when the preset conditions change; the temperature detection module is used to output a temperature detection signal and the first level signal according to the first voltage, the first current and the bias current.

2. The over-temperature protection circuit according to claim 1, characterized in that: The over-temperature protection circuit further includes a second current compensation module, the second current compensation module is connected to the first current compensation module, and the second current compensation module is used to be connected to the power supply module; The second current compensation module is used to perform current compensation on the first current compensation module when the power supply voltage output by the power supply module changes.

3. The over-temperature protection circuit according to claim 1 or 2, characterized in that: The first current compensation module includes a first resistor, a second resistor, a third resistor, a first field effect transistor, a second field effect transistor, a third field effect transistor and a fourth field effect transistor. The gate of the first field effect transistor is connected to the bandgap reference module, the source of the first field effect transistor and the source of the second field effect transistor are both used to connect to the power module, the drain of the first field effect transistor is respectively connected to the gate of the third field effect transistor and the first end of the first resistor, the second end of the first resistor is respectively connected to the first end of the second resistor and the source of the fourth field effect transistor, the gate of the fourth field effect transistor is connected to the temperature detection module, the source of the third field effect transistor is respectively connected to the drain of the second field effect transistor, the gate of the second field effect transistor and the temperature detection module, the drain of the third field effect transistor is connected to the first end of the third resistor, and the drain of the fourth field effect transistor, the second end of the second resistor and the second end of the third resistor are all grounded.

4. The over-temperature protection circuit according to claim 2, characterized in that: The second current compensation module includes a fourth resistor, a fifth field effect transistor, a sixth field effect transistor and a seventh field effect transistor. The gate of the fifth field effect transistor is respectively connected to the gate of the sixth field effect transistor, the drain of the sixth field effect transistor and the source of the seventh field effect transistor. The source of the fifth field effect transistor and the source of the sixth field effect transistor are both used to connect to the power module, the drain of the fifth field effect transistor is connected to the first current compensation module, the gate of the seventh field effect transistor is respectively connected to the drain of the seventh field effect transistor and the first end of the fourth resistor, and the second end of the fourth resistor is grounded.

5. The over-temperature protection circuit according to claim 1 or 2, characterized in that: The bandgap reference module includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a first triode, a second triode, a third triode, a fourth triode, an operational amplifier, an eighth field effect transistor, a ninth field effect transistor, a tenth field effect transistor, an eleventh field effect transistor and a twelfth field effect transistor, the emitter of the first triode is respectively connected to the base of the second triode and the drain of the eighth field effect transistor, the emitter of the second triode is respectively connected to the first end of the fifth resistor, the drain of the ninth field effect transistor, the inverting input end of the operational amplifier and the temperature detection module, the non-inverting input end of the operational amplifier is respectively connected to the drain of the tenth field effect transistor, the first end of the sixth resistor and the first end of the eighth resistor, the second end of the eighth resistor is connected to the emitter of the third triode, the base of the third triode is respectively connected to the drain of the eleventh field effect transistor and the drain of the fourth triode The emitter is connected, the drain of the twelfth field effect tube is connected to the first end of the seventh resistor, the output end of the operational amplifier is respectively connected to the gate of the eighth field effect tube, the gate of the ninth field effect tube, the gate of the tenth field effect tube, the gate of the eleventh field effect tube, the gate of the twelfth field effect tube, the first current compensation module and the temperature detection module, the source of the eighth field effect tube, the source of the ninth field effect tube, the source of the tenth field effect tube, the source of the eleventh field effect tube and the source of the twelfth field effect tube are all used to connect to the power supply module, the base of the first triode, the collector of the first triode, the collector of the second triode, the second end of the fifth resistor, the second end of the sixth resistor, the collector of the third triode, the base of the fourth triode, the collector of the fourth triode and the second end of the seventh resistor are all grounded.

6. The over-temperature protection circuit according to claim 1 or 2, characterized in that: The temperature detection module includes a temperature detection unit and a logic unit, the temperature detection unit is respectively connected to the bandgap reference module, the first current compensation module and the logic unit, the logic unit is connected to the first current compensation module, and the temperature detection unit is used to be connected to the power supply module; The temperature detection unit is used to output a second level signal to the logic unit according to the first voltage, the first current and the bias current; the logic unit is used to output the temperature detection signal and the first level signal according to the second level signal.

7. The over-temperature protection circuit according to claim 6, characterized in that: The temperature detection unit includes a ninth resistor, a tenth resistor, a thirteenth field effect transistor, a fourteenth field effect transistor, a fifteenth field effect transistor, a sixteenth field effect transistor and a seventeenth field effect transistor, the gate of the thirteenth field effect transistor is connected to the bandgap reference module, the drain of the thirteenth field effect transistor is connected to the first end of the ninth resistor, the source of the thirteenth field effect transistor is respectively connected to the gate of the fourteenth field effect transistor and the drain of the fifteenth field effect transistor, the source of the fourteenth field effect transistor is respectively connected to the drain of the sixteenth field effect transistor and the drain of the tenth field effect transistor The gate of the seventh field effect transistor is connected, the gate of the fifteenth field effect transistor is connected to the first current compensation module, the gate of the sixteenth field effect transistor is connected to the bandgap reference module, the source of the fifteenth field effect transistor, the source of the sixteenth field effect transistor and the source of the seventeenth field effect transistor are all used to connect to the power module, the drain of the seventeenth field effect transistor is respectively connected to the first end of the tenth resistor and the logic unit, and the second end of the ninth resistor, the drain of the fourteenth field effect transistor and the second end of the tenth resistor are all grounded.

8. The over-temperature protection circuit according to claim 6, characterized in that: The logic unit includes a Schmitt trigger and an inverter, the input end of the Schmitt trigger is connected to the temperature detection unit, the output end of the Schmitt trigger is respectively connected to the input end of the inverter and the first current compensation module, and the output end of the inverter is used to output the temperature detection signal.

9. A power chip, characterized in that: The invention comprises the over-temperature protection circuit as described in any one of claims 1 to 8.

10. An electronic device, characterized in that: The invention comprises the over-temperature protection circuit as described in any one of claims 1 to 8.

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