CN217935069U - Over-temperature protection circuit and electronic equipment - Google Patents
Over-temperature protection circuit and electronic equipment Download PDFInfo
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- CN217935069U CN217935069U CN202221577028.8U CN202221577028U CN217935069U CN 217935069 U CN217935069 U CN 217935069U CN 202221577028 U CN202221577028 U CN 202221577028U CN 217935069 U CN217935069 U CN 217935069U
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Abstract
The utility model provides an excess temperature protection circuit and electronic equipment, include: the temperature sensing module is used for sensing the ambient temperature and converting the temperature signal into a voltage signal; the over-temperature judging module is connected with the output end of the temperature sensing module and is used for generating an over-temperature signal when the voltage value of the voltage signal reaches a set value; the over-temperature protection module is connected with the output end of the over-temperature judgment module and used for executing over-temperature protection action according to the over-temperature signal; the hysteresis self-locking module is connected between the output end of the temperature sensing module and the ground, is controlled by an over-temperature signal, and is used for reducing the voltage value of the voltage signal based on the parallel resistor when the over-temperature does not occur and increasing the voltage value of the voltage signal by cutting off the parallel resistor when the over-temperature occurs. Through the utility model provides an excess temperature protection circuit has solved current detection circuitry and has had the problem that the testing result can take place to shake.
Description
Technical Field
The utility model relates to an integrated circuit design field especially relates to an excess temperature protection circuit and electronic equipment.
Background
High-temperature failure is the most common failure type in electronic components, and can cause more serious consequences and even cause fire after high-temperature failure; in order to take measures to eliminate the risk in the stage of the star fire, detection and alarm means are necessary.
The conventional detection circuit has the problem of jumping up and down at a temperature point, namely after the temperature point is reached, the detection result of the detection circuit is also shaken because the temperature has small up-and-down shaking, which is not beneficial to the processing of the detection result. In view of this, how to prevent the detection result from jittering is a technical problem that needs to be solved by those skilled in the art.
SUMMERY OF THE UTILITY MODEL
In view of the above shortcomings in the prior art, an object of the present invention is to provide an over-temperature protection circuit and an electronic device, which solve the problem of the existing detection circuit that the detection result will shake.
In order to achieve the above objects and other related objects, the present invention provides an over-temperature protection circuit, which includes:
the temperature sensing module is used for sensing the ambient temperature and converting the temperature signal into a voltage signal;
the over-temperature judging module is connected with the output end of the temperature sensing module and is used for generating an over-temperature signal when the voltage value of the voltage signal reaches a set value;
the over-temperature protection module is connected with the output end of the over-temperature judgment module and used for executing over-temperature protection action according to the over-temperature signal;
the hysteresis self-locking module is connected between the output end of the temperature sensing module and the ground, is controlled by the over-temperature signal, and is used for reducing the voltage value of the voltage signal based on the parallel resistor when the over-temperature does not occur and increasing the voltage value of the voltage signal by cutting off the parallel resistor path when the over-temperature occurs.
Optionally, the temperature sensing module comprises: the thermistor comprises a thermistor body, a first resistor and a second resistor; the first end of the thermistor is connected with a power supply voltage, and the second end of the thermistor is connected with the first end of the first resistor; the second end of the first resistor is connected with the first end of the second resistor and serves as the output end of the temperature sensing module; and the second end of the second resistor is grounded.
Optionally, the over-temperature determining module includes: a third resistor and a first NMOS tube; the first end of the third resistor is connected with the output end of the temperature sensing module, and the second end of the third resistor is connected with the grid end of the first NMOS tube; and the drain end of the first NMOS tube is used as the output end of the over-temperature judgment module, and the source end of the first NMOS tube is grounded.
Optionally, the over-temperature protection module includes: a fourth resistor, a fifth resistor and an execution unit; the first end of the fourth resistor is connected with the output end of the over-temperature judging module, the second end of the fourth resistor is connected with the first end of the fifth resistor and the execution unit, and the second end of the fifth resistor is connected with a power supply voltage; the execution unit executes an over-temperature protection action based on the over-temperature signal.
Optionally, the over-temperature protection module further includes: and the detection module is connected with the second end of the fourth resistor and used for detecting temperature change according to the over-temperature signal.
Optionally, the detection module includes an MCU.
Optionally, the hysteretic self-locking module comprises: a second NMOS transistor and a sixth resistor; the gate end of the second NMOS tube is connected with the output end of the over-temperature judging module, the drain end of the second NMOS tube is connected with the output end of the temperature sensing module, and the source end of the second NMOS tube is connected with the first end of the sixth resistor; and the second end of the sixth resistor is grounded.
The utility model also provides an electronic equipment, electronic equipment includes: an over-temperature protection circuit as claimed in any preceding claim.
As described above, the over-temperature protection circuit and the electronic device of the present invention utilize the hysteresis self-locking module to reduce the voltage value of the voltage signal based on the parallel resistor when the over-temperature does not occur, and increase the voltage value of the voltage signal by cutting off the parallel resistor path when the over-temperature occurs, so that the circuit has the hysteresis function, and the temperature detection result does not shake near the temperature point; moreover, when the detection module is not available or fails, the over-temperature protection can be carried out. The utility model discloses a circuit structure is simple, and is with low costs, and has high reliability.
Drawings
Fig. 1 shows a schematic diagram of the over-temperature protection circuit of the present invention.
Description of the element reference numerals
10. Over-temperature protection circuit
100. Temperature sensing module
200. Over-temperature judgment module
300. Over-temperature protection module
301. Execution unit
400. Hysteresis self-locking module
500. Detection module
Detailed Description
The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will be readily apparent to those skilled in the art from the disclosure herein. The present invention can also be implemented or applied through other different specific embodiments, and various details in the present specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.
Please refer to fig. 1. It should be understood that the structure, ratio, size and the like shown in the drawings attached to the present specification are only used for matching with the content disclosed in the specification, so as to be known and read by those skilled in the art, and are not used for limiting the limit conditions that the present invention can be implemented, so that the present invention has no technical essential meaning, and any structure modification, ratio relationship change or size adjustment should still fall within the scope that the technical content disclosed in the present invention can cover without affecting the function that the present invention can produce and the purpose that the present invention can achieve. Meanwhile, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for convenience of description, and are not intended to limit the scope of the present invention, and changes or adjustments of the relative relationship thereof may be made without substantial technical changes, and the present invention is also regarded as the scope of the present invention.
As shown in fig. 1, the present embodiment provides an over-temperature protection circuit 10, where the over-temperature protection circuit 10 includes: the temperature sensing module 100, the over-temperature determining module 200, the over-temperature protection module 300, and the hysteresis self-locking module 400. Further, the over-temperature protection circuit 10 further includes: a detection module 500.
The temperature sensing module 100 is used for sensing an ambient temperature and converting a temperature signal into a voltage signal.
Specifically, the temperature sensing module 100 includes: the thermistor comprises a thermistor N1, a first resistor R1 and a second resistor R2; the first end of the thermistor N1 is connected with a power supply voltage VCC, and the second end of the thermistor N1 is connected with the first end of the first resistor R1; the second end of the first resistor R1 is connected to the first end of the second resistor R2 and serves as the output end of the temperature sensing module 100; the second end of the second resistor R2 is grounded. The thermistor N1 is a negative temperature coefficient thermistor, that is, an NTC thermistor.
In this example, the thermistor N1 is used to sense the ambient temperature, and the divided voltage of the first resistor R1 and the second resistor R2 is used to convert the temperature signal into a voltage signal; as the temperature increases, the resistance of the thermistor N1 decreases, and the voltage at the output terminal of the temperature sensing module 100 increases. In the embodiment of the present application, the resistance values, types, structures, and the like of the first resistor R1 and the second resistor R2 are not specifically made, for example, the first resistor may be a single resistor, or may also be a plurality of resistors connected in series and/or in parallel, and the like. In addition, the second resistor and other resistors in the embodiment of the present application are similar to each other, and are not described again.
The over-temperature determining module 200 is connected to the output end of the temperature sensing module 100, and is configured to generate an over-temperature signal when the voltage value of the voltage signal reaches a set value.
Specifically, the over-temperature determining module 200 includes: a third resistor R3 and a first NMOS tube NM1; a first end of the third resistor R3 is connected to the output end of the temperature sensing module 100, and a second end is connected to the gate end of the first NMOS transistor NM1; the drain terminal of the first NMOS transistor NM1 serves as the output terminal of the over-temperature determination module 200, and the source terminal is grounded.
In this example, when the voltage value of the voltage signal reaches a predetermined value, the first NMOS transistor NM1 is turned on to lower the voltage at the drain terminal from a high level to a low level, which is equivalent to generating an over-temperature signal. It should be noted that the set value determines the temperature point of the circuit, which can be set by selecting the third resistor R3 with a suitable resistance.
The over-temperature protection module 300 is connected to the output end of the over-temperature judgment module 200, and is configured to execute an over-temperature protection action according to the over-temperature signal.
Specifically, the over-temperature protection module 300 includes: a fourth resistor R4, a fifth resistor R5 and an execution unit 301; a first end of the fourth resistor R4 is connected to the output end of the over-temperature determining module 200, a second end of the fourth resistor R4 is connected to a first end of the fifth resistor R5 and the execution unit 301, and a second end of the fifth resistor R5 is connected to the power supply voltage VCC; the execution unit 301 executes an over-temperature protection action, such as cutting off a power supply voltage, based on the over-temperature signal, and at this time, the execution unit 301 may be implemented by using a control switch.
The hysteresis self-locking module 400 is connected between the output terminal of the temperature sensing module 200 and the ground, and is controlled by an over-temperature signal, and is configured to decrease the voltage value of the voltage signal based on the parallel resistor when the over-temperature does not occur, and increase the voltage value of the voltage signal by cutting off the parallel resistor path when the over-temperature occurs.
Specifically, the hysteresis self-locking module 400 includes: a second NMOS transistor NM2 and a sixth resistor R6; the gate end of the second NMOS tube NM2 is connected to the output end of the over-temperature determining module 200, the drain end is connected to the output end of the temperature sensing module 100, and the source end is connected to the first end of the sixth resistor R6; the second end of the sixth resistor R6 is grounded.
In this example, the on-off of the parallel resistance path is controlled by the on-off of the second NMOS transistor NM2, so as to implement: when the over-temperature does not occur, the sixth resistor R6 is connected with the second resistor R2 in parallel, and when the over-temperature occurs, the sixth resistor R6 is not connected with two ends of the second resistor R2 in parallel any more.
The detecting module 500 is connected to a second end of the fourth resistor R4, and is configured to detect a temperature change according to the over-temperature signal. The detection module includes an MCU (micro control unit), and the detection module may also be implemented by other structures, such as a processor, a controller, and the like.
Next, referring to fig. 1, the operation process of the over-temperature protection circuit of the present embodiment will be described in detail.
As the temperature rises, the resistance of the thermistor N1 decreases, and the voltage at the output terminal of the temperature sensing module 100 rises; the grid end of the second NMOS tube NM2 is connected with a power supply voltage VCC through a fourth resistor R4 and a fifth resistor R5, so that the second NMOS tube NM2 is conducted, and the second resistor R2 is connected with a sixth resistor R6 in parallel; at this time, the voltage at the output terminal of the temperature sensing module 100 is
Wherein, U VCC Is the value of the supply voltage, R N1 Is the resistance value of the thermistor, R 1 Is the resistance value of the first resistor, R 2 Is the resistance value of the second resistor, R 6 Is the resistance value of the sixth resistor;
if the voltage value reaches a set value, the first NMOS transistor NM1 is turned on, and at this time, the voltage at the output terminal of the over-temperature determining module 200 is decreased from a high level to a low level, so as to lower the gate voltage of the second NMOS transistor NM2, turn off the second NMOS transistor NM2, switch the parallel resistor path, that is, the sixth resistor R6 is no longer connected in parallel with the second resistor R2, so as to increase the voltage at the output terminal of the temperature sensing module 100, and at this time, the voltage at this point is changed to be the voltage at the output terminal of the temperature sensing module 100
Wherein, U VCC Is the value of the supply voltage, R N1 Is the resistance value of the thermistor, R 1 Is the resistance value of the first resistor, R 2 Is the resistance value of the second resistor; at the same temperature, U 1 <U 2 The influence of small temperature reduction is avoided;
when the voltage at the output end of the over-temperature determining module 200 is decreased from the high level to the low level, the change signal enters the execution unit 301 through the fourth resistor R4 to trigger the execution unit 301 to execute the over-temperature protection action; meanwhile, the variation signal may also enter the detection module 500 through the fourth resistor R4, and the detection module 500 may detect and identify a temperature variation according to the variation signal.
Correspondingly, the embodiment also provides electronic equipment, and the electronic equipment comprises the over-temperature protection circuit.
In practical application, the electronic device may be an electronic component, a functional chip (such as a power chip), or other terminal devices, and this embodiment does not limit this.
To sum up, the utility model discloses an excess temperature protection circuit and electronic equipment utilizes hysteresis self-locking module when not taking place the excess temperature, reduces the voltage value of voltage signal based on parallel resistance, when taking place the excess temperature, raises the voltage value of voltage signal through cutting off parallel resistance passageway to make the circuit have the hysteresis function, realize that the temperature testing result can not take place the shake near the temperature point; moreover, when the detection module is not available or fails, the over-temperature protection can be carried out. The utility model discloses a circuit structure is simple, and is with low costs, and has high reliability.
The above embodiments are merely illustrative of the principles and effects of the present invention, and are not to be construed as limiting the invention. Modifications and variations can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which may be made by those skilled in the art without departing from the spirit and technical spirit of the present invention shall be covered by the claims of the present invention.
Claims (8)
1. An over-temperature protection circuit, comprising:
the temperature sensing module is used for sensing the ambient temperature and converting a temperature signal into a voltage signal;
the over-temperature judging module is connected with the output end of the temperature sensing module and is used for generating an over-temperature signal when the voltage value of the voltage signal reaches a set value;
the over-temperature protection module is connected with the output end of the over-temperature judgment module and used for executing over-temperature protection action according to the over-temperature signal;
the hysteresis self-locking module is connected between the output end of the temperature sensing module and the ground, is controlled by the over-temperature signal, and is used for reducing the voltage value of the voltage signal based on the parallel resistor when the over-temperature does not occur and increasing the voltage value of the voltage signal by cutting off the parallel resistor path when the over-temperature occurs.
2. The over-temperature protection circuit according to claim 1, wherein the temperature sensing module comprises: the thermistor comprises a thermistor, a first resistor and a second resistor;
the first end of the thermistor is connected with a power supply voltage, and the second end of the thermistor is connected with the first end of the first resistor; the second end of the first resistor is connected with the first end of the second resistor and serves as the output end of the temperature sensing module; and the second end of the second resistor is grounded.
3. The over-temperature protection circuit according to claim 1, wherein the over-temperature determination module comprises: a third resistor and a first NMOS tube;
the first end of the third resistor is connected with the output end of the temperature sensing module, and the second end of the third resistor is connected with the grid end of the first NMOS tube; and the drain end of the first NMOS tube is used as the output end of the over-temperature judgment module, and the source end of the first NMOS tube is grounded.
4. The over-temperature protection circuit according to claim 1, wherein the over-temperature protection module comprises: a fourth resistor, a fifth resistor and an execution unit;
the first end of the fourth resistor is connected with the output end of the over-temperature judging module, the second end of the fourth resistor is connected with the first end of the fifth resistor and the execution unit, and the second end of the fifth resistor is connected with a power supply voltage; the execution unit executes an over-temperature protection action based on the over-temperature signal.
5. The over-temperature protection circuit of claim 4, wherein the over-temperature protection module further comprises: and the detection module is connected with the second end of the fourth resistor and used for detecting temperature change according to the over-temperature signal.
6. The over-temperature protection circuit according to claim 5, wherein the detection module comprises an MCU.
7. The over-temperature protection circuit according to claim 1, wherein the hysteretic self-locking module comprises: a second NMOS transistor and a sixth resistor;
the gate end of the second NMOS tube is connected with the output end of the over-temperature judging module, the drain end of the second NMOS tube is connected with the output end of the temperature sensing module, and the source end of the second NMOS tube is connected with the first end of the sixth resistor; and the second end of the sixth resistor is grounded.
8. An electronic device, characterized in that the electronic device comprises: the excess temperature protection circuit of any one of claims 1-7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221577028.8U CN217935069U (en) | 2022-06-22 | 2022-06-22 | Over-temperature protection circuit and electronic equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221577028.8U CN217935069U (en) | 2022-06-22 | 2022-06-22 | Over-temperature protection circuit and electronic equipment |
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| Publication Number | Publication Date |
|---|---|
| CN217935069U true CN217935069U (en) | 2022-11-29 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221577028.8U Active CN217935069U (en) | 2022-06-22 | 2022-06-22 | Over-temperature protection circuit and electronic equipment |
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| Country | Link |
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| CN (1) | CN217935069U (en) |
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- 2022-06-22 CN CN202221577028.8U patent/CN217935069U/en active Active
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