CN218958528U - Self-locking protection circuit, electronic equipment and vehicle - Google Patents
Self-locking protection circuit, electronic equipment and vehicle Download PDFInfo
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- CN218958528U CN218958528U CN202221937775.8U CN202221937775U CN218958528U CN 218958528 U CN218958528 U CN 218958528U CN 202221937775 U CN202221937775 U CN 202221937775U CN 218958528 U CN218958528 U CN 218958528U
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Abstract
The utility model relates to a self-locking protection circuit, electronic equipment and a vehicle with the electronic equipment. The self-locking protection circuit comprises: a comparator, wherein the input voltage is connected with the inverting input end of the comparator through a first resistor, and the non-inverting input end of the comparator is connected with the reference voltage V ref The comparator is connected with the power supply circuit, and activates a protection signal when the output of the comparator is in a low level; and a field effect transistor, wherein the output end of the comparator is connected with the output end of the comparatorThe grid electrode of the field effect tube is connected with the drain electrode of the field effect tube through a second resistor, the source electrode of the field effect tube is connected with the first power supply voltage VDD 1 。
Description
Technical Field
The present utility model relates to the field of circuit design. In particular, the utility model relates to a self-locking protection circuit, an electronic device and a vehicle with the electronic device.
Background
Protection circuits for overvoltage or overcurrent signals have been widely used in electrical products such as automotive electronics to prevent damage to the electronics and potential safety hazards caused by the overvoltage or overcurrent signals.
Currently, some of the prior art uses integrated chips (e.g., overvoltage and overcurrent protection chips) to protect electronic devices, however, the overvoltage and overcurrent protection chips currently on the market have the defect of high price. Another part of the prior art utilizes discrete devices to build a hardware protection circuit, and the cost of the scheme is far lower than that of an integrated chip, but the number of the used devices is large and the logic is complex, so that the high failure risk exists.
Disclosure of Invention
In view of the above problems, the present utility model aims to provide a protection circuit with a simple circuit structure, self-locking capability, resettable capability and adjustable threshold value, so as to reduce the number of devices to the greatest extent while ensuring the high effectiveness of the circuit, thereby saving the hardware cost. In addition, an electronic device and a vehicle using the protection circuit are also provided.
According to one aspect of the present utility model, there is provided a self-locking protection circuit comprising: a comparator, wherein the input voltage is connected with the inverting input end of the comparator through a first resistor, and the non-inverting input end of the comparator is connected with the reference voltage V ref The comparator is connected with the power supply circuit, and activates a protection signal when the output of the comparator is in a low level; the output end of the comparator is connected with the grid electrode of the field effect tube, the drain electrode of the field effect tube is connected with the inverting input end of the comparator through a second resistor, and the source electrode of the field effect tube is connected with a first power supply voltage VDD 1 。
Alternatively or additionally to the above, in an embodiment of the utility model, a self-locking protection circuitIn the circuit, the FET is turned on when the comparator outputs a low level to convert the voltage V at the inverting input terminal of the comparator comp- Higher than the reference voltage V ref 。
Alternatively or additionally to the above, in the self-locking protection circuit according to an embodiment of the present utility model, an inverting input terminal of the comparator is grounded through a third resistor.
Alternatively, or in addition, to the above, in a self-locking protection circuit according to an embodiment of the present utility model,
here, R is 1 、R 2 、R 3 The resistances of the first resistor, the second resistor and the third resistor are respectively.
Alternatively or additionally to the above, the self-locking protection circuit according to an embodiment of the present utility model further includes: and the collector of the NPN triode is connected with the inverting input end of the comparator through a fourth resistor, and the base of the NPN triode is used for receiving a reset signal.
In an alternative or addition to the above, in the self-locking protection circuit according to an embodiment of the present utility model, the NPN transistor is turned on when the reset signal is at a high level to convert the voltage V at the inverting input terminal of the comparator comp- Pulled lower than the reference voltage V ref 。
Alternatively, or in addition, to the above, in a self-locking protection circuit according to an embodiment of the present utility model,
here, R is 1 、R 2 、R 3 、R 4 The resistance values of the first resistor, the second resistor, the third resistor and the fourth resistor are respectively VDD 2 For the input voltage。
Alternatively or additionally, in the self-locking protection circuit according to an embodiment of the present utility model, an output terminal of the comparator is connected to one terminal of a pull-up resistor, and the other terminal of the pull-up resistor is connected to the third power supply voltage VDD 3 。
In addition or alternatively, in the self-locking protection circuit according to an embodiment of the present utility model, the field effect transistor is a PMOS transistor.
According to still another aspect of the present utility model, there is provided an electronic apparatus including: according to the self-locking protection circuit disclosed by the utility model, the self-locking protection circuit comprises a circuit board; and the signal processing module is used for processing the detection signal and generating a voltage signal as an input of the self-locking protection circuit.
According to yet another aspect of the present utility model, there is provided a vehicle comprising a self-locking protection circuit according to one aspect of the present utility model.
First, a self-latch protection circuit according to one or more embodiments of the present utility model implements latching of a protection signal using only one field effect transistor and one resistor by connecting the output of a comparator to the gate of a field effect transistor (e.g., PMOS transistor).
Secondly, the self-locking protection circuit according to one or more embodiments of the present utility model directly connects the reset signal with the NPN-type triode, and connects the collector of the NPN-type triode with the inverting input terminal of the comparator through a resistor, so that the reset function of the protection signal is realized by using only one NPN-type triode and one resistor.
In summary, the self-locking protection circuit according to one or more embodiments of the present utility model utilizes a very simple structural circuit and lower hardware cost to realize the latch and reset functions of the overvoltage, overcurrent and overtemperature protection circuit, so that the number of devices used is reduced to the greatest extent, and the overall failure rate of the circuit is reduced.
Drawings
The foregoing and/or other aspects and advantages of the present utility model will become more apparent and more readily appreciated from the following description of the various aspects taken in conjunction with the accompanying drawings in which like or similar elements are designated with the same reference numerals. The drawings include:
FIG. 1 shows a schematic block diagram of a self-locking protection circuit 10 according to one embodiment of the utility model;
FIG. 2 shows an equivalent structure diagram of a self-locking protection circuit when a PMOS tube is turned on according to one embodiment of the utility model; and
fig. 3 shows an equivalent structure diagram of the self-locking protection circuit when the NPN transistor is turned on according to an embodiment of the utility model.
Detailed Description
In this specification, the utility model will be described more fully with reference to the accompanying drawings in which illustrative embodiments of the utility model are shown. This utility model may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. The embodiments are presented in order to fully complete the disclosure herein to more fully convey the scope of the utility model to those skilled in the art.
Terms such as "comprising" and "including" mean that the technical solution of the present utility model does not exclude the presence of other elements or steps than those directly or explicitly stated in the description and claims. The terms such as "first" and "second" do not denote the order of units in terms of time, space, size, etc. but rather are merely used to distinguish one unit from another.
It is to be understood that the techniques of this disclosure are generally applicable to electric vehicles, including, but not limited to, electric-only vehicles (BEV), hybrid Electric Vehicles (HEV), fuel cell vehicles (FCEV), and the like.
Referring now to fig. 1, fig. 1 shows a schematic block diagram of a self-locking protection circuit 10 according to one embodiment of the utility model. As shown in fig. 1, the self-locking protection circuit 10 includes a comparing unit 110 and a self-locking function unit 120.
The comparison unit 110 includes a comparator 111 and a first resistor 112. The comparison unit 110 is used for comparing the input voltage VDD 2 And presetThe voltage threshold value (i.e., the reference voltage Vref) of (a) is compared to output a high level or a low level. Illustratively, the above-mentioned input voltage VDD 2 May be a voltage signal generated by processing a detection signal (e.g., a temperature signal to be detected, a voltage signal, a current signal, etc.) by a signal processing module.
Specifically, the comparator 111 includes a non-inverting input terminal, an inverting input terminal, and an output terminal. An input voltage is connected to an inverting input terminal of a comparator 111 via a first resistor 112, and a non-inverting input terminal of the comparator is connected to a reference voltage V ref Are connected. Illustratively, the reference voltage V ref Is set to a critical value for determining whether the detection signal exceeds a preset limit (e.g., temperature limit, voltage limit, current limit), reference voltage V ref The size of the circuit can be adjusted through the signal processing chip, so that the circuit is more flexible and has wider applicability. If the reference voltage V ref An inverted input voltage V greater than that of comparator 111 comp- The comparator 111 outputs a high voltage; if the reference voltage V ref An inverted input voltage V less than that of comparator 111 comp- The comparator 111 outputs a low voltage.
Further, the comparator 111 is also configured to activate a protection signal when the output is low to trigger a protection action against overvoltage, overtemperature, overcurrent (e.g., cut off the power supply).
Optionally, the comparing unit 110 further includes a third resistor 113, wherein an inverting input terminal of the comparator 111 is grounded through the third resistor 113.
Optionally, the comparator 111 further comprises a pull-up resistor 114. Specifically, the output end of the comparator 111 is connected to one end of a pull-up resistor, and the other end of the pull-up resistor is connected to the third power supply voltage VDD 3 。
The self-locking function unit 120 shown in fig. 1 is used to detect when the protection signal is activated (i.e., the reference voltage V ref An inverted input voltage V less than that of comparator 111 comp- ) Thereafter, no matter what the input voltage VDD 2 The reverse input voltage V of the comparator can be input by the amount of falling back comp- Forced pull-up above reference voltage V ref To achieve protection of signalsAnd (5) latching.
Specifically, self-locking functional unit 120 includes a field effect transistor 121 and a second resistor 122. The output end of the comparator 111 is connected with the grid electrode of the field effect tube 121, the drain electrode of the field effect tube 121 is connected with the inverting input end of the comparator 111 through the second resistor 122, and the source electrode of the field effect tube 121 is connected with the first power supply voltage VDD 1 . Illustratively, the field effect transistor 121 is a PMOS transistor. As can be seen from the characteristics of the PMOS transistor, when the source voltage of the PMOS transistor is larger than the gate voltage by a certain value, the PMOS transistor is turned on. Therefore, the power supply voltage VDD can be properly set 1 So that the PMOS transistor can be turned on when the comparator 111 output is low.
Referring now to fig. 2, fig. 2 is an equivalent block diagram of a self-locking protection circuit when a PMOS transistor is turned on according to an embodiment of the present utility model.
As shown in fig. 2, when PMOS is turned on, the comparator 111 has an inverted input voltage V comp- The voltage drop of the PMOS tube can be calculated (neglected):
here, R1, R2, and R3 are the resistance values of the first resistor 112, the second resistor 122, and the third resistor 113, respectively.
It can be appreciated that the values of R1, R2 and R3 can be reasonably set to ensure that no matter what input voltage VDD is after the PMOS tube is conducted 2 How much falls back, the inverting input voltage V of the comparator comp- Can all be kept higher than the reference voltage V ref . In other words, the following formula can be made constant by reasonably setting the values of R1, R2, R3:
with continued reference now to FIG. 1, the self-locking protection circuit 10 may optionally further include a reset function 130 for inverting the comparator's inverting input voltage V when the reset signal is active comp- Forced pullingLower than the reference voltage V ref To effect a reset of the protection circuit.
Specifically, the reset function unit 130 includes an NPN-type triode 131 and a fourth resistor 132, wherein a collector of the NPN-type triode 131 is connected to an inverting input terminal of the comparator 111 through the fourth resistor 132, a base of the NPN-type triode 131 is configured to receive a reset signal, and an emitter of the NPN-type triode 131 is grounded. As can be seen from the characteristics of the NPN transistor, when the reset signal is at the high level, the NPN transistor 131 is turned on.
Referring now to fig. 3, fig. 3 is an equivalent block diagram of a self-locking protection circuit when an NPN transistor is turned on according to an embodiment of the utility model.
As shown in fig. 3, when the NPN transistor is turned on, the comparator 111 has an inverted input voltage V comp- The voltage drop of the PMOS tube and the voltage drop of the NPN triode can be calculated by the following steps:
here, R1, R2, R3, and R4 are the resistances of the first resistor 112, the second resistor 122, the third resistor 113, and the fourth resistor 132, respectively.
It can be appreciated that the inverted input voltage V of the comparator can be ensured after the NPN triode is turned on by reasonably setting the values of R1, R2, R3 and R4 comp- Will be able to remain below the reference voltage V ref . In other words, the following formula can be made constant by reasonably setting the values of R1, R2, R3, R4:
according to another aspect of the present utility model, there is provided an electronic device comprising a self-locking protection circuit according to one aspect of the present utility model (e.g., the self-locking protection circuit 10, 20, 30 as described above) and a signal processing module for processing a detection signal (e.g., a temperature signal, a voltage signal, a current signal, etc. to be detected) and generating a voltage signal as an input to the self-locking protection circuit.
According to another aspect of the present utility model, there is provided a vehicle comprising a self-locking protection circuit according to one aspect of the present utility model (e.g., the self-locking protection circuit 10, 20, 30 as described above).
The self-locking protection circuit according to one or more embodiments of the present utility model realizes the latching of a protection signal by connecting the output of a comparator to the gate of a field effect transistor (e.g., PMOS transistor) using only one field effect transistor and one resistor; the reset signal is directly connected with the NPN type triode, and the collector of the NPN type triode is connected with the inverting input end of the comparator through a resistor, so that the reset function of the protection signal is realized by only using one NPN type triode and one resistor. The self-locking protection circuit according to one or more embodiments of the present utility model realizes the latch and reset functions of the overvoltage, overcurrent and overtemperature protection circuit by using a very simple structural circuit and a lower hardware cost, and reduces the overall failure rate of the circuit while minimizing the number of devices used.
The foregoing disclosure is not intended to limit the disclosure to the precise form disclosed or to the particular field of use. Thus, it is contemplated that various alternative embodiments and/or modifications of the present disclosure are possible in light of the present disclosure, whether explicitly described or implied herein. Having thus described embodiments of the present disclosure, it will be recognized by one of ordinary skill in the art that changes may be made in form and detail without departing from the scope of the present disclosure. Accordingly, the disclosure is limited only by the claims.
Claims (11)
1. A self-locking protection circuit, comprising:
a comparator, wherein the input voltage is connected with the inverting input end of the comparator through a first resistor, and the non-inverting input end of the comparator is connected with the reference voltage V ref The comparator is connected with the power supply circuit, and activates a protection signal when the output of the comparator is in a low level; and
a field effect transistor, wherein theThe output end of the comparator is connected with the grid electrode of the field effect tube, the drain electrode of the field effect tube is connected with the inverting input end of the comparator through a second resistor, and the source electrode of the field effect tube is connected with a first power supply voltage VDD 1 。
2. The self-locking protection circuit of claim 1 wherein the field effect transistor is turned on when the comparator output is low to pull the voltage V at the inverting input of the comparator comp- Higher than the reference voltage V ref 。
3. The self-locking protection circuit of claim 1, wherein the inverting input of the comparator is grounded through a third resistor.
4. The self-locking protection circuit of claim 3, wherein,
here, R is 1 、R 2 、R 3 The resistances of the first resistor, the second resistor and the third resistor are respectively.
5. The self-locking protection circuit of claim 3, further comprising:
and the collector of the NPN triode is connected with the inverting input end of the comparator through a fourth resistor, and the base of the NPN triode is used for receiving a reset signal.
6. The self-locking protection circuit of claim 5, wherein the NPN transistor turns on when the reset signal is high to switch the voltage V at the inverting input of the comparator comp- Pulled lower than the reference voltage V ref 。
7. The self-locking protection circuit of claim 5, wherein,
here, R is 1 、R 2 、R 3 、R 4 The resistance values of the first resistor, the second resistor, the third resistor and the fourth resistor are respectively VDD 2 Is the input voltage.
8. The self-locking protection circuit of claim 1, wherein an output terminal of the comparator is connected to one end of a pull-up resistor, and the other end of the pull-up resistor is connected to a third power supply voltage VDD 3 。
9. The self-locking protection circuit of claim 1, wherein the field effect transistor is a PMOS transistor.
10. An electronic device, comprising:
the self-locking protection circuit of any one of claims 1-9; and
and the signal processing module is used for processing the detection signal and generating a voltage signal as an input of the self-locking protection circuit.
11. A vehicle comprising a self-locking protection circuit as claimed in any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221937775.8U CN218958528U (en) | 2022-07-25 | 2022-07-25 | Self-locking protection circuit, electronic equipment and vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221937775.8U CN218958528U (en) | 2022-07-25 | 2022-07-25 | Self-locking protection circuit, electronic equipment and vehicle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN218958528U true CN218958528U (en) | 2023-05-02 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221937775.8U Active CN218958528U (en) | 2022-07-25 | 2022-07-25 | Self-locking protection circuit, electronic equipment and vehicle |
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| Country | Link |
|---|---|
| CN (1) | CN218958528U (en) |
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2022
- 2022-07-25 CN CN202221937775.8U patent/CN218958528U/en active Active
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