Over-temperature protection circuit and chip

Abstract

The utility model discloses an over-temperature protection circuit and a chip. The over-temperature protection circuit comprises a current supply module, a cascode current mirror, a trim resistor and a voltage comparison module. The current providing module is used for providing current with a zero temperature coefficient; the cascode current mirror is used for carrying out mirror image processing on the current with the zero temperature coefficient and outputting the current with the zero temperature coefficient to a first end of the trim resistor; the trim resistor is used for converting the current with the zero temperature coefficient into detection voltage and outputting the detection voltage to a first input end of the voltage comparison module; the voltage comparison module is used for outputting an over-temperature indication signal according to the detection voltage and the reference voltage. The over-temperature protection circuit provided by the utility model has higher over-temperature detection precision, and the safety of the chip in the working process can be further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit, in particular to an over-temperature protection circuit and a chip. BACKGROUND

[0002] With the rapid development of electronic technology, the application scenarios of power management chips are more and more, the integration of power management chips is higher and higher, the power consumption is also larger and larger, and the temperature application range of power management chips is also wider and wider. In order to protect the integrated circuit chip from high temperature damage, a special over-temperature protection circuit needs to be designed. When the temperature exceeds a certain threshold, the over-temperature protection circuit outputs an off signal, so that the chip stops working partially or completely. How to accurately design the temperature protection circuit is very important for protecting the power management chip under the increasingly stringent temperature requirements. The inventor found that the over-temperature protection circuit has the problem of low precision in some scenarios. CONTENT OF THE UTILITY MODEL

[0003] In view of this, the present application provides an over-temperature protection circuit and a chip to solve the problem of low precision of the traditional over-temperature protection scheme in some scenarios.

[0004] The over-temperature protection circuit provided by the present application comprises a current providing module, a common-source common-gate current mirror, a trim resistor and a voltage comparison module; the output end of the current providing module is connected to the input end of the common-source common-gate current mirror; the output end of the common-source common-gate current mirror is connected to the first end of the trim resistor and the first input end of the voltage comparison module respectively; the second input end of the voltage comparison module is used for inputting a reference voltage, and the output end is used for outputting an over-temperature indication signal; the second end of the trim resistor is grounded.

[0005] The current providing module is used for providing a zero-temperature coefficient current.

[0006] The common-source common-gate current mirror is used for mirroring the zero-temperature coefficient current and outputting the zero-temperature coefficient current to the first end of the trim resistor.

[0007] The trim resistor is used for converting the zero-temperature coefficient current into a detection voltage and outputting the detection voltage to the first input end of the voltage comparison module.

[0008] The voltage comparison module is used for outputting an over-temperature indication signal according to the detection voltage and the reference voltage; the over-temperature indication signal comprises a high level signal and a low level signal, and the voltage comparison module outputs the high level signal when the detection voltage is greater than the reference voltage, and outputs the low level signal when the detection voltage is less than the reference voltage.

[0009] Optionally, the current providing module comprises a negative temperature voltage providing unit, an operational amplifier, a first NMOS tube and a negative temperature resistor; a first end of the negative temperature voltage providing unit is grounded, and a second end thereof is connected to a non-inverting input end of the operational amplifier; an inverting input end of the operational amplifier is respectively connected to a source of the first NMOS tube and a first end of the negative temperature resistor, and an output end thereof is connected to a gate of the first NMOS tube; a drain of the first NMOS tube is connected to an input end of the common-source common-gate current mirror as an output end of the current providing module; a second end of the negative temperature resistor is grounded; the negative temperature voltage providing unit is configured to provide a negative temperature coefficient voltage; the negative temperature resistor is configured to convert the negative temperature coefficient voltage into the zero-temperature coefficient current; and the first NMOS tube inputs the zero-temperature coefficient current into the common-source common-gate current mirror.

[0010] Optionally, the negative temperature voltage providing unit comprises a second NMOS tube, a third NMOS tube and a fourth NMOS tube; a drain of the second NMOS tube is configured to access an input current, and is respectively connected to a non-inverting input end of the operational amplifier and a gate of the second NMOS tube, and a source thereof is respectively connected to a drain of the third NMOS tube and a gate of the third NMOS tube; a source of the third NMOS tube is respectively connected to a drain of the fourth NMOS tube and a gate of the fourth NMOS tube; and a source of the fourth NMOS tube is grounded.

[0011] Optionally, the over-temperature protection circuit further comprises a current source; a first end of the current source is configured to access a preset voltage, and a second end thereof is connected to a drain of the second NMOS tube, and is configured to provide the input current.

[0012] Optionally, the common-source common-gate current mirror comprises a first PMOS tube, a second PMOS tube, a third PMOS tube, a fourth PMOS tube and a preset resistor; a source of the first PMOS tube is configured to access a preset voltage, a drain thereof is connected to a source of the third PMOS tube, and a gate thereof is respectively connected to a gate of the second PMOS tube, a drain of the third PMOS tube and a first end of the preset resistor; a source of the second PMOS tube is configured to access the preset voltage, and a drain thereof is connected to a source of the fourth PMOS tube; a gate of the third PMOS tube is respectively connected to a gate of the fourth PMOS tube and a second end of the preset resistor, and is connected to an input end of the common-source common-gate current mirror; a drain of the fourth PMOS tube is connected to an output end of the common-source common-gate current mirror as a first end of the trim resistor.

[0013] Optionally, the first end of the trim resistor is provided with a trim site, and is configured to access a test device of the trim resistor, so as to adjust a temperature inflection point of the trim resistor.

[0014] Optionally, the trim resistor is a negative temperature coefficient resistor.

[0015] Optionally, the voltage comparison module comprises a comparator and a level processing unit; a positive input terminal of the comparator is connected to a first terminal of the trim resistor to access the detection voltage, a negative input terminal accesses the reference voltage, and an output terminal outputs the over-temperature indication signal through the level processing unit; the comparator is configured to output a high level signal when the detection voltage is greater than the reference voltage, and output a low level signal when the detection voltage is less than the reference voltage; and the level processing unit is configured to perform level conversion processing on the level signal output by the comparator, so that the converted signal represents an over-temperature state.

[0016] Optionally, the level processing unit comprises an even number of inverters connected in series.

[0017] The application also provides a chip comprising any of the over-temperature protection circuits.

[0018] In the over-temperature protection circuit and the chip, the current providing module 110 can provide a zero temperature coefficient current to avoid the temperature influence on the mirror-processed current, the common-source common-gate current mirror 120 is used to mirror process the zero temperature coefficient current, the trim resistor R3 converts the zero temperature coefficient current into the detection voltage V1, the accuracy of the mirror-processed current is improved, the voltage comparison module 130 outputs the over-temperature indication signal OTP according to the detection voltage V1 and the reference voltage Vref, other structures of the chip can make corresponding responses according to the over-temperature indication signal OTP, the working process of the chip is safer, the over-temperature protection circuit has higher detection accuracy, and the safety of the working process of the chip is further improved.

[0019] Further, the common-source common-gate current mirror structure is implemented by a PMOS tube, and the area is smaller under the same current processing capacity, so that the size of the corresponding over-temperature protection circuit can be reduced.

[0020] Further, the first terminal of the trim resistor R3 is provided with a trim site, the number of trim sites can be adjusted to obtain a relatively accurate negative temperature coefficient voltage at a certain temperature point with temperature change, so as to realize an over-temperature protection circuit with accurate temperature inflection point setting; and the trim resistor R3 is a negative temperature coefficient resistor, so that the voltage comparison module 130 can compare the voltage of the negative temperature coefficient device with the reference voltage to output the over-temperature indication signal OTP, the temperature coefficient dependent device can be reduced, the influence of temperature and process on the over-temperature detection process can be reduced, and the reliability of the over-temperature protection circuit is improved. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor based on these drawings.

[0022] Figure 1 is a schematic diagram of an over-temperature protection circuit structure of an embodiment of the present application;

[0023] Figure 2 is a schematic diagram of an over-temperature protection circuit structure of another embodiment of the present application;

[0024] Figure 3 is a schematic diagram of an over-temperature protection circuit structure of another embodiment of the present application. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments only constitute some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. In the case of no conflict, each of the following embodiments and its technical features can be combined with each other.

[0026] The first aspect of the present application provides an over-temperature protection circuit, which is used to output an over-temperature indication signal, so that the chip can obtain the over-temperature state in time and perform corresponding responses such as current limiting, to ensure the safety during the working process of the corresponding chip.

[0027] Reference Figure 1 As shown in the figure, the over-temperature protection circuit includes a current providing module 110, a common-source common-gate current mirror 120, a trim resistor R3 and a voltage comparison module 130. The output end of the current providing module 110 is connected to the input end of the common-source common-gate current mirror 120. The output end of the common-source common-gate current mirror 120 is respectively connected to the first end of the trim resistor R3 and the first input end of the voltage comparison module 130. The second input end of the voltage comparison module 130 is used to input a reference voltage Vref, and the output end is used to output an over-temperature indication signal OTP. The second end of the trim resistor R3 is grounded.

[0028] The current providing module 110 is used to provide a zero-temperature coefficient current. The current providing module 110 can include a negative-temperature coefficient resistor, generate a negative-temperature coefficient voltage, and apply the negative-temperature coefficient voltage to the negative-temperature coefficient resistor to generate a zero-temperature coefficient current.

[0029] The common-source common-gate current mirror 120 is configured to mirror process the zero-temperature-coefficient current and output the zero-temperature-coefficient current to a first end of the trim resistor R3. The common-source common-gate current mirror 120 can provide more accurate mirror processing to improve the accuracy of mirror processing of the zero-temperature-coefficient current.

[0030] The trim resistor R3 is configured to convert the zero-temperature-coefficient current into a detection voltage V1 and output the detection voltage V1 to a first input end of the voltage comparison module 130. Optionally, the trim resistor R3 can be a negative-temperature-coefficient resistor, and the higher the temperature, the smaller the resistance value. The trim resistor at one end of the trim resistor R3 also becomes smaller.

[0031] The voltage comparison module 130 is configured to output an over-temperature indication signal OTP according to the detection voltage V1 and a reference voltage Vref. The over-temperature indication signal OTP generally includes two states, one of which represents that the temperature of the chip is in a normal range, i.e., a non-over-temperature state, and the other of which represents that the temperature of the chip is relatively high, i.e., an over-temperature state (which can also be referred to as an over-heat state).

[0032] Optionally, the reference voltage Vref can be set according to the temperature bearing characteristics of the corresponding chip. When the temperature of the chip changes from the non-over-temperature state to the over-temperature state, the signal output by the voltage comparison module 130 changes from a signal representing the non-over-temperature state to a signal representing the over-temperature state. For example, if the trim resistor R3 is a negative-temperature-coefficient resistor, when the temperature of the chip is in the normal range, the voltage comparison module 130 outputs a high-level signal. As the temperature rises, if the detection voltage V1 on the trim resistor R3 becomes smaller, when the detection voltage V1 is smaller than the reference voltage Vref, the voltage comparison module 130 outputs a low-level signal, representing that the corresponding chip is currently in an over-temperature state.

[0033] In the over-temperature protection circuit described above, the current providing module 110 can provide a zero-temperature-coefficient current to avoid the influence of temperature on the mirror-processed current. The common-source common-gate current mirror 120 is configured to mirror process the zero-temperature-coefficient current, the trim resistor R3 is configured to convert the zero-temperature-coefficient current into a detection voltage V1, and the voltage comparison module 130 is configured to output an over-temperature indication signal OTP according to the detection voltage V1 and a reference voltage Vref. This allows other structures of the chip to respond to the over-temperature indication signal OTP, so that the working process of the chip is safer. The over-temperature protection circuit described above has higher detection accuracy and can further improve the safety of the working process of the chip.

[0034] In some embodiments, the reference Figure 2As shown, the current providing module 110 includes a negative temperature voltage providing unit 111, an operational amplifier APM, a first NMOS tube NM1 and a negative temperature resistance R2. The first end of the negative temperature voltage providing unit 111 is grounded, and the second end is connected to the non-inverting input terminal (also referred to as the positive input terminal) of the operational amplifier APM; the inverting input terminal (also referred to as the negative input terminal) of the operational amplifier APM is respectively connected to the source of the first NMOS tube NM1 and the first end of the negative temperature resistance R2, and the output terminal is connected to the gate of the first NMOS tube NM1; the drain of the first NMOS tube NM1 is used as the output terminal of the current providing module 111, and is connected to the input terminal of the common-source common-gate current mirror 120; and the second end of the negative temperature resistance R2 is grounded.

[0035] The negative temperature voltage providing unit 111 described above is used to provide a negative temperature coefficient voltage, and the negative temperature resistance R2 is used to convert the negative temperature coefficient voltage into a zero temperature coefficient current, so as to input the zero temperature coefficient current into the common-source common-gate current mirror 120 through the first NMOS tube NM1. Specifically, if the negative temperature coefficient voltage provided by the negative temperature voltage providing unit 111 is VT, and the resistance value of the negative temperature resistance R2 is R2, then the zero temperature coefficient current is: I1=VT / R2, VT is the negative temperature coefficient voltage, and R2 is a negative temperature coefficient resistance, so I1 is a relative zero temperature coefficient current.

[0036] In some examples, with reference to Figure 3 As shown, the negative temperature voltage providing unit 111 includes a second NMOS tube NM2, a third NMOS tube NM3 and a fourth NMOS tube NM4; wherein the second NMOS tube NM2, the third NMOS tube NM3 and the fourth NMOS tube NM4 are NMOS tubes of the same configuration. The drain of the second NMOS tube NM2 is used to access an input current I0, and is respectively connected to the non-inverting input terminal of the operational amplifier APM and the gate of the second NMOS tube NM2, and the source is respectively connected to the drain of the third NMOS tube NM3 and the gate of the third NMOS tube NM3; the source of the third NMOS tube NM3 is respectively connected to the drain of the fourth NMOS tube NM4 and the gate of the fourth NMOS tube NM4; and the source of the fourth NMOS tube NM4 is grounded.

[0037] In the negative temperature voltage providing unit 111, the gate and the drain of the second NMOS transistor NM2, the third NMOS transistor NM3 and the fourth NMOS transistor NM4 are short-circuited to form a diode connection. When the chip is in stable operation, the voltage at the non-inverting input terminal of the operational amplifier APM is 3Vth, which is the threshold voltage of the three NMOS transistors. At this time, the voltage at the inverting input terminal of the operational amplifier APM is equal to the voltage at the non-inverting input terminal of the operational amplifier APM, i.e. 3Vth. The current at the output terminal of the common-source and common-gate current mirror 120 is I1=3Vth / R2, where Vth is the negative temperature coefficient voltage and R2 is a negative temperature coefficient resistor. Therefore, I1 is a current with a relative zero temperature coefficient.

[0038] In some examples, as shown in Figure 3 The over-temperature protection circuit further includes a current source I0. A first end of the current source I0 is connected to a preset voltage VDD, and a second end of the current source I0 is connected to the drain of the second NMOS transistor NM2, so as to provide the input current I0.

[0039] In some embodiments, as shown in Figure 2 and Figure 3 The common-source and common-gate current mirror 120 includes a first PMOS transistor PM1, a second PMOS transistor PM2, a third PMOS transistor PM3, a fourth PMOS transistor PM4 and a preset resistor R1. The first PMOS transistor PM1 and the second PMOS transistor PM2 have the same size, and the third PMOS transistor PM3 and the fourth PMOS transistor PM4 have the same size. The source of the first PMOS transistor PM1 is connected to the preset voltage VDD, the drain of the first PMOS transistor PM1 is connected to the source of the third PMOS transistor PM3, and the gate of the first PMOS transistor PM1 is connected to the gate of the second PMOS transistor PM2, the drain of the third PMOS transistor PM3 and a first end of the preset resistor R1. The source of the second PMOS transistor PM2 is connected to the preset voltage VDD, and the drain of the second PMOS transistor PM2 is connected to the source of the fourth PMOS transistor PM4. The gate of the third PMOS transistor PM3 is connected to the gate of the fourth PMOS transistor PM4 and a second end of the preset resistor R2, and serves as an input terminal of the common-source and common-gate current mirror 120. The drain of the fourth PMOS transistor PM4 serves as an output terminal of the common-source and common-gate current mirror 120, and is connected to a first end of the trim resistor R3. The common-source and common-gate current mirror structure provided in the embodiment can make the mirror processing of the current with a zero temperature coefficient more accurate. The common-source and common-gate current mirror 120 is implemented by using PMOS transistors, so that the size of the corresponding over-temperature protection circuit can be reduced under the same current processing capacity.

[0040] In some embodiments, as shown in Figure 2 and Figure 3As shown, a first end of the trim resistor R3 is provided with a trim site for connecting a test device of the trim resistor R3 to adjust the temperature inflection point of the trim resistor R3. The trim site can be connected to the test device at a corresponding test time to perform corresponding test adjustment, so as to ensure that the detection voltage V1 is at a relatively stable voltage value under the influence of temperature and process angle, thereby achieving the purpose of accurately adjusting the temperature inflection point.

[0041] In some embodiments, the trim resistor R3 is a negative temperature coefficient resistor, and the voltage comparison module 130 can output an over-temperature indication signal OTP by comparing the voltage of the negative temperature coefficient device with a reference voltage, thereby reducing the dependence on temperature coefficient devices and reducing the influence of temperature and process on the over-temperature detection process.

[0042] In some examples, as Figure 2 As shown, the voltage comparison module 130 includes a comparator COMP and a level processing unit 131. A positive input end of the comparator COMP is connected to a first end of the trim resistor R3 to connect the detection voltage V1, a negative output end is connected to the reference voltage Vref, and an output end outputs the over-temperature indication signal OTP through the level processing unit 131.

[0043] The comparator COMP is configured to output a high-level signal when the detection voltage V1 is greater than the reference voltage Vref, and output a low-level signal when the detection voltage V1 is less than the reference voltage Vref.

[0044] The level processing unit 131 is configured to perform level conversion processing on the level signal output by the comparator COMP, so that the converted signal OTP can more clearly represent the over-temperature state, improve the stability of the subsequent component of the chip in identifying the over-temperature indication signal OTP, and thus improve the reliability of the over-temperature protection circuit during operation. The positive input voltage of the comparator COMP is V1=I1*R3, so the detection voltage V1 is a negative temperature coefficient voltage; the reference voltage Vref is a zero-temperature drift voltage separated from the bandgap reference module; because the detection voltage V1 is a negative temperature coefficient voltage, the detection voltage V1 will be less than the reference voltage Vref at a certain temperature point, at which time the level signal of the output point of the comparator COMP will flip, and the over-temperature indication signal OTP will flip from 1 to 0. This temperature point is the over-temperature protection point of the over-temperature protection circuit.

[0045] Specifically, the level processing unit 131 includes an even number of inverters connected in series, so as to maintain the level characteristics of the level signal output by the COMP on the basis of performing level conversion processing on the level signal output by the COMP. Alternatively, the level processing unit 131 includes two inverters connected in series, as Figure 3As shown, the level processing unit 131 includes a first inverter INV1 and a second inverter INV2, the input end of the first inverter INV1 is connected to the output end of the comparator COMP, and the output end outputs the over-temperature indication signal OTP through the second inverter INV2.

[0046] The over-temperature protection circuit has the following advantages. The current providing module 110 can provide a zero-temperature-coefficient current to avoid that the current processed by the mirror processing is affected by temperature. The zero-temperature-coefficient current is processed by the common-source common-gate current mirror 120 to convert the zero-temperature-coefficient current into the detection voltage V1 by the trim resistor R3, so that the accuracy of the mirror processing can be improved. The over-temperature indication signal OTP is output by the voltage comparison module 130 according to the detection voltage V1 and the reference voltage Vref, so that other structures of the chip can make corresponding responses according to the over-temperature indication signal OTP to make the chip working process safer. The over-temperature protection circuit has higher detection accuracy, and the safety of the chip working process can be further improved. The common-source common-gate current mirror structure is implemented by a PMOS tube, and the area is smaller under the same current processing capacity, so that the size of the corresponding over-temperature protection circuit can be reduced. The first end of the trim resistor R3 is provided with a trim point, and the number of trim bits can be adjusted to obtain a relatively accurate negative temperature coefficient voltage at a certain temperature point to realize an over-temperature protection circuit with an accurately set temperature inflection point. The trim resistor R3 is a negative temperature coefficient resistor, so that the voltage comparison module 130 can compare the voltage of the negative temperature coefficient device with the reference voltage to output the over-temperature indication signal OTP, which can reduce the dependence on devices with temperature coefficients, reduce the influence of temperature and process on the over-temperature detection process, and improve the reliability of the over-temperature protection circuit.

[0047] The second aspect of the present application provides a chip, which includes the over-temperature protection circuit of any of the above embodiments.

[0048] Optionally, the chip can further include a processing module, which can obtain the over-temperature indication signal OTP output by the voltage comparison module 130, and control the chip to work according to the over-temperature indication signal OTP, for example, to limit the current of at least part of the components of the chip or to shut down at least part of the components of the chip when the over-temperature indication signal OTP represents an over-temperature state, so as to limit the heat generation of the chip and improve the safety of the chip working process.

[0049] The power amplifier includes the over-temperature protection circuit of any of the above embodiments, and has all the advantages of the over-temperature protection circuit of any of the above embodiments, which will not be described here.

[0050] Although the present application has been shown and described with respect to one or more implementations, equivalent alterations and modifications will occur to others skilled in the art based on the foregoing description and accompanying drawings. The application includes all such modifications and alterations and is limited only by the scope of the following claims. In particular, with respect to the various functions performed by the above described components, the terms (e.g., "means for") used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the exemplary implementation illustrated by the present application.

[0051] That is, the above-described embodiments are merely exemplary implementations of the present application, and do not limit the scope of the patent of the present application, and equivalent structures or equivalent processes made by using the contents of the specification and drawings of the present application, such as the combination of technical features among the embodiments, or direct or indirect application in other related technical fields, are also included in the scope of the patent of the present application.

[0052] In addition, in the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, for structural elements with the same or similar properties, the present application can use the same or different reference numerals for identification. Furthermore, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features with "first", "second" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0053] In this application, the use of the singular includes the plural unless specifically stated otherwise. In this application, the use of "or" means "and / or" unless stated otherwise. In this application, the use of "an" includes "one or more". In this application, the use of "another" means "at least a second" or "at least a third" unless context clearly indicates otherwise. In this application, the use of "another" means "at least a second" or "at least a third" unless context clearly indicates otherwise. In this application, the use of "another" means "at least a second" or "at least a third" unless context clearly indicates otherwise. In this application, the use of "another" means "at least a second" or "at least a third" unless context clearly indicates otherwise. In this application, the use of "another" means "at least a second" or "at least a third" unless context clearly indicates otherwise. In this application, the use of "another" means "at least a second" or "at least a third" unless context clearly indicates otherwise. In this application, the use of "another" means "at least a second" or "at least a third" unless context clearly indicates otherwise. In this application, the use of "another" means "at least a second" or "at least a third" unless context clearly indicates otherwise. In this application, the use of "another" means "at least a second" or "at least a third" unless context clearly indicates otherwise. In this application, the use of "another" means "at least a second" or "at least a third" unless context clearly indicates otherwise. In this application, the use of "another" means "at least a second" or "at least a third" unless context clearly indicates otherwise. In this application, the use of "another" means "at least a second" or "at

Claims

1. An over-temperature protection circuit, characterized in that, The over-temperature protection circuit includes a current supply module, a common-source cascode current mirror, a trim resistor, and a voltage comparison module. The output of the current supply module is connected to the input of the common-source cascode current mirror. The output of the common-source cascode current mirror is connected to the first terminal of the trim resistor and the first input of the voltage comparison module. The second input of the voltage comparison module is used to connect to a reference voltage, and its output is used to output an over-temperature indication signal. The second terminal of the trim resistor is grounded. The current providing module is used to provide a current with zero temperature coefficient; The common-source cascode current mirror is used to mirror the zero-temperature coefficient current and output the zero-temperature coefficient current to the first terminal of the trim resistor. The trim resistor is a resistor with a negative temperature coefficient, used to convert the zero temperature coefficient current into a detection voltage, and output the detection voltage to the first input terminal of the voltage comparison module; The voltage comparison module is used to output a high-level signal when the detected voltage is greater than the reference voltage, and to output a low-level signal when the detected voltage is less than the reference voltage.

2. The over-temperature protection circuit according to claim 1, characterized in that, The current supply module includes a negative temperature voltage supply unit, an operational amplifier, a first NMOS transistor, and a negative temperature resistor; The first terminal of the negative temperature voltage providing unit is grounded, and the second terminal is connected to the non-inverting input terminal of the operational amplifier; the inverting input terminal of the operational amplifier is connected to the source of the first NMOS transistor and the first terminal of the negative temperature resistor, respectively, and the output terminal is connected to the gate of the first NMOS transistor; the drain of the first NMOS transistor serves as the output terminal of the current providing module and is connected to the input terminal of the common source common gate current mirror; the second terminal of the negative temperature resistor is grounded. The negative temperature coefficient voltage providing unit is used to provide a negative temperature coefficient voltage; The negative temperature coefficient resistor is used to convert the negative temperature coefficient voltage into the zero temperature coefficient current; The first NMOS transistor inputs the zero-temperature coefficient current into the common-source cascode current mirror.

3. The over-temperature protection circuit according to claim 2, characterized in that, The negative temperature voltage providing unit includes a second NMOS transistor, a third NMOS transistor, and a fourth NMOS transistor; The drain of the second NMOS transistor is used to receive the input current and is connected to the non-inverting input terminal of the operational amplifier and the gate of the second NMOS transistor, respectively. The source is connected to the drain and gate of the third NMOS transistor, respectively. The source of the third NMOS transistor is connected to the drain and gate of the fourth NMOS transistor, respectively. The source of the fourth NMOS transistor is grounded.

4. The over-temperature protection circuit according to claim 3, characterized in that, The over-temperature protection circuit also includes a current source; The first end of the current source is used to connect to a preset voltage, and the second end is connected to the drain of the second NMOS transistor to provide the input current.

5. The over-temperature protection circuit according to claim 1, characterized in that, The common-source common-gate current mirror includes a first PMOS transistor, a second PMOS transistor, a third PMOS transistor, a fourth PMOS transistor, and a preset resistor; The source of the first PMOS transistor is connected to a preset voltage, the drain is connected to the source of the third PMOS transistor, and the gate is connected to the gate of the second PMOS transistor, the drain of the third PMOS transistor, and the first terminal of the preset resistor. The source of the second PMOS transistor is connected to the preset voltage, and the drain is connected to the source of the fourth PMOS transistor. The gate of the third PMOS transistor is connected to the gate of the fourth PMOS transistor and the second terminal of the preset resistor, and serves as the input terminal of the common-source common-gate current mirror. The drain of the fourth PMOS transistor serves as the output terminal of the common-source common-gate current mirror and is connected to the first terminal of the trim resistor.

6. The over-temperature protection circuit according to claim 1, characterized in that, The first end of the trim resistor is provided with a trim point for connecting to the test equipment of the trim resistor to adjust the temperature inflection point of the trim resistor.

7. The over-temperature protection circuit according to claim 1, characterized in that, The voltage comparison module includes a comparator and a level processing unit; The positive input terminal of the comparator is connected to the first terminal of the trim resistor to receive the detection voltage, the negative output terminal is connected to the reference voltage, and the output terminal outputs the over-temperature indication signal through the level processing unit. The comparator is configured to output a high-level signal when the detected voltage is greater than the reference voltage, and to output a low-level signal when the detected voltage is less than the reference voltage; The level processing unit is used to perform level conversion processing on the level signal output by the comparator so that the converted signal represents the over-temperature state.

8. The over-temperature protection circuit according to claim 7, characterized in that, The level processing unit includes an even number of inverters connected in series.

9. A chip, characterized in that, Includes the over-temperature protection circuit as described in any one of claims 1 to 8.

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