Power failure protection circuit and electronic device

Abstract

The application relates to the field of power electronics, and discloses a power-off protection circuit and an electronic device, which comprise a conversion circuit, a super capacitor and a switching circuit. The conversion circuit converts an external power supply into first direct current and provides the first direct current to the switching circuit and the super capacitor. The super capacitor is used for charging by the first direct current. When the external power supply normally supplies power, the switching circuit provides an input voltage to a voltage stabilizing circuit by the first direct current. When the external power supply is powered off, the switching circuit is switched to provide the input voltage to the voltage stabilizing circuit by the super capacitor. The voltage stabilizing circuit obtains second direct current by voltage stabilizing processing on the input voltage and provides the second direct current to a data transmission module and a voltage monitoring circuit for power supply. When the voltage monitoring circuit monitors that the voltage of the second direct current is lower than a preset voltage threshold, the voltage monitoring circuit sends a reset signal to the data transmission module to reset the data transmission module. In this way, the problem that the running state of the data transmission module may be abnormal due to a slow power-off process after the super capacitor is added is solved, and the data transmission module is reset during power-off to avoid abnormal running.

Description

Technical Field

[0001] This application relates to the field of power electronics, and more particularly to a power failure protection circuit and electronic device. Background Technology

[0002] Data acquisition and transmission are becoming increasingly important in various application scenarios. For example, data acquisition and transmission are required in Internet of Things (IoT) and industrial automation technologies.

[0003] In practical applications, if a data transmission module is immediately shut down due to an unexpected power outage, data loss is highly likely, severely impacting the reliability and integrity of data transmission. Therefore, supercapacitors are typically added to the circuitry of the data transmission module to temporarily maintain power supply during mains power failures, ensuring safe data transmission and storage. However, adding a supercapacitor slows down the power outage process, potentially causing the data transmission module to operate below its specified operating voltage range, leading to abnormal operation. Utility Model Content

[0004] The purpose of this application is to provide at least one power-off protection circuit and electronic device, which can at least solve the problem that the slow power-off process after adding a supercapacitor may cause abnormal operation of the data transmission module, and at least achieve the effect of avoiding abnormal operation of the data transmission module when power is off.

[0005] A first aspect of this application provides a power-off protection circuit, comprising: a data transmission module, a supercapacitor, a conversion circuit, a switching circuit, a voltage regulator circuit, and a voltage monitoring circuit; wherein:

[0006] The conversion circuit is connected to the switching circuit and the supercapacitor respectively, and is used to convert the external power supply into a first DC power and supply it to the switching circuit and the supercapacitor.

[0007] The supercapacitor is used to be charged by the first DC current;

[0008] The switching circuit is also connected to the supercapacitor and the voltage regulator circuit respectively, and is used to provide input voltage to the voltage regulator circuit using the first DC power when the external power supply is normal; and to switch to using the supercapacitor to provide input voltage to the voltage regulator circuit when the external power supply is off.

[0009] The voltage regulator circuit is connected to the data transmission module and the voltage monitoring circuit respectively, and is used to obtain a second DC power by regulating the input voltage and provide it to the data transmission module and the voltage monitoring circuit for power supply;

[0010] The voltage monitoring circuit is connected to the data transmission module and is used to send a reset signal to the data transmission module to reset the data transmission module when the voltage of the second DC power supply is lower than a preset voltage threshold.

[0011] Optionally, the first input terminal of the switching circuit is connected to the power output terminal of the conversion circuit, the second input terminal is connected to the first terminal of the supercapacitor, and the output terminal is connected to the input terminal of the voltage regulator circuit; the second terminal of the supercapacitor is grounded.

[0012] The switching circuit includes: a first switching transistor, a second switching transistor, a third switching transistor, a first resistor, and a second resistor;

[0013] Wherein, the gate of the first switching transistor is connected to the drain of the second switching transistor and the first end of the first resistor, the source is connected to the output of the switching circuit, and the drain is connected to the first input of the switching circuit.

[0014] The gate of the second switching transistor is connected to the first input terminal of the switching circuit, and its source is grounded;

[0015] The gate of the third switching transistor is connected to the first input terminal of the switching circuit and the first terminal of the second resistor, the source is connected to the output terminal of the switching circuit, the first input terminal of the switching circuit and the second terminal of the first resistor, and the drain is connected to the second input terminal of the switching circuit.

[0016] The second terminal of the second resistor is grounded.

[0017] Optionally, the first switch, the second switch, and the third switch are MOSFETs.

[0018] Optional features also include: a pre-charging circuit;

[0019] The conversion circuit is connected to the supercapacitor through the pre-charging circuit;

[0020] The pre-charging circuit is used to pre-charge the supercapacitor.

[0021] Optionally, the input terminal of the pre-charging circuit is connected to the power output terminal of the conversion circuit, and the output terminal is connected to the first terminal of the supercapacitor; the second terminal of the supercapacitor is grounded.

[0022] The pre-charging circuit includes: a diode and a third resistor;

[0023] The positive terminal of the diode is connected to the input terminal of the pre-charging circuit, and the negative terminal is connected to the first terminal of the third resistor.

[0024] The second end of the third resistor is connected to the output end of the pre-charging circuit.

[0025] Optionally, the power status indicator terminal of the conversion circuit is connected to the output terminal of the voltage regulator circuit through a fourth resistor, and is also connected to the first input terminal of the data transmission module, for sending a power status indicator signal to the data transmission module.

[0026] The data transmission module is used to trigger a data saving operation when the received power status indication signal indicates that the external power supply has failed.

[0027] Optionally, the power input terminal of the conversion circuit is connected to the external power supply, and the power output terminal is connected to the first terminal of the supercapacitor and the first input terminal of the switching circuit, respectively.

[0028] The conversion circuit includes: a DC-DC chip, a Schottky diode, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a fifth resistor, a sixth resistor, and an inductor;

[0029] The power input terminal and enable terminal of the DC-DC chip are respectively connected to the power input terminal of the conversion circuit, the bootstrap input terminal is connected to the first terminal of the first capacitor, the switching node is respectively connected to the second terminal of the first capacitor, the negative terminal of the Schottky diode, and the first terminal of the inductor, the feedback terminal is respectively connected to the first terminal of the fifth resistor, the first terminal of the sixth resistor, and the first terminal of the second capacitor, and the ground terminal is grounded.

[0030] The second terminal of the fifth resistor, the second terminal of the second capacitor, the first terminal of the third capacitor, the first terminal of the fourth capacitor, the first terminal of the fifth capacitor, and the second terminal of the inductor are respectively connected to the power output terminal of the conversion circuit.

[0031] The positive terminal of the Schottky diode, the second terminal of the third capacitor, the second terminal of the fourth capacitor, the second terminal of the fifth capacitor, and the second terminal of the sixth resistor are all grounded.

[0032] Optionally, the input terminal of the voltage regulator circuit is connected to the output terminal of the switching circuit, and the output terminal is connected to the second input terminal of the data transmission module and the input terminal of the voltage monitoring circuit, respectively.

[0033] The voltage regulator circuit includes: a low-voltage linear regulator, an eighth resistor, a ninth resistor, and a sixth capacitor;

[0034] The power input terminal of the low-voltage linear regulator is connected to the input terminal of the voltage regulator circuit, the power output terminal is connected to the output terminal of the voltage regulator circuit, and the adjustable voltage terminal is connected to the output terminal of the voltage regulator circuit through the eighth resistor and grounded through the ninth resistor.

[0035] The first terminal of the sixth capacitor is connected to the output terminal of the voltage regulator circuit, and the second terminal is grounded.

[0036] A second aspect of this application provides an electronic device including a power-off protection circuit as described in any of the above.

[0037] Optionally, the electronic device is an IoT industrial device.

[0038] The advantages of this application compared to the prior art are:

[0039] The power failure protection circuit of this application uses an external power source as the main power supply and a supercapacitor as the backup power supply. A switching circuit switches between the external power source and the backup power supply. The conversion circuit can convert the external power source into a first DC power and supply it to the switching circuit and the supercapacitor. The supercapacitor can be charged by the first DC power. When the external power source is working normally, the switching circuit can use the first DC power to provide input voltage to the voltage regulator circuit. When the external power source fails, the switching circuit can switch to using the supercapacitor to provide input voltage to the voltage regulator circuit. The voltage regulator circuit obtains a second DC power by regulating the input voltage and supplies it to the data transmission module and the voltage monitoring circuit. In this way, it can be ensured that after the main power source fails, it can still be powered by the supercapacitor as a backup power source for a period of time to save data in time, effectively prevent data loss, and ensure data integrity and security. Furthermore, a voltage monitoring circuit is used to monitor the voltage of the second DC power supply. When the voltage of the second DC power supply is lower than the preset voltage threshold, a power outage may occur. At this time, a reset signal is sent to the data transmission module to reset the data transmission module, thus avoiding abnormalities caused by the data transmission module operating under low voltage and improving operational stability and reliability. Therefore, the problem of abnormal operation of the data transmission module caused by the slowed power-off process after adding a supercapacitor is solved.

[0040] It is understandable that the beneficial effects of the second aspect mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0041] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, and these illustrative descriptions do not constitute a limitation on the embodiments.

[0042] Figure 1 This is a schematic diagram of the power-off protection circuit provided in one embodiment of this application. Figure 1 ;

[0043] Figure 2 This is a schematic diagram of the power-off protection circuit provided in another embodiment of this application. Figure 2 ;

[0044] Figure 3This is a schematic diagram of the power-off protection circuit provided in another embodiment of this application. Figure 3 ;

[0045] Figure 4 This is a schematic diagram of the power-off protection circuit provided in another embodiment of this application. Figure 4 ;

[0046] Figure 5 This is a schematic diagram of the power-off protection circuit provided in another embodiment of this application. Figure 5 . Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this application to help readers better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments. The division of the various embodiments below is for the convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0048] To facilitate understanding of the embodiments of this application, the relevant content regarding the data transmission module will be introduced first.

[0049] With the rapid development of IoT and industrial automation technologies, data acquisition and transmission are becoming increasingly important in various application scenarios.

[0050] In practical applications, if a data transmission module is immediately shut down due to an unexpected power outage, data loss is highly likely, severely impacting the reliability and integrity of data transmission. Therefore, supercapacitors are typically added to the circuitry of the data transmission module to temporarily maintain power supply during mains power failures, ensuring safe data transmission and storage. However, adding a supercapacitor slows down the power outage process, potentially causing the data transmission module to operate below its specified operating voltage range. This can lead to abnormal operation, primarily due to controller malfunctions within the module, resulting in issues such as data processing errors and abnormal data transmission, ultimately affecting the stability and reliability of the entire system.

[0051] The embodiments of this application relate to a power-off protection circuit.

[0052] Compared to existing technologies, the implementation of this application employs an external power source as the main power supply and a supercapacitor as the backup power supply. A switching circuit switches between the external power supply and the backup power supply. The conversion circuit converts the external power supply into a first DC current and supplies it to the switching circuit and the supercapacitor. The supercapacitor can be charged using the first DC current. When the external power supply is working normally, the switching circuit can use the first DC current to provide input voltage to the voltage regulator circuit. When the external power supply fails, the switching circuit can switch to using the supercapacitor to provide input voltage to the voltage regulator circuit. The voltage regulator circuit obtains a second DC current by regulating the input voltage and supplies it to the data transmission module and the voltage monitoring circuit. In this way, it can be ensured that even after the main power supply fails, the supercapacitor can still provide power for a period of time to save data in a timely manner, effectively preventing data loss and ensuring data integrity and security. Furthermore, a voltage monitoring circuit is used to monitor the voltage of the second DC power supply. When the voltage of the second DC power supply is lower than the preset voltage threshold, a power outage may occur. At this time, a reset signal is sent to the data transmission module to reset the data transmission module, thus avoiding abnormalities caused by the data transmission module operating under low voltage and improving operational stability and reliability. Therefore, the problem of abnormal operation of the data transmission module caused by the slowed power-off process after adding a supercapacitor is solved.

[0053] The following is a detailed description of the implementation details of the power-down protection circuit in this embodiment. The following content is only for the convenience of understanding and is not necessary for implementing this solution.

[0054] The embodiments of this application provide a power-down protection circuit, such as... Figure 1 As shown, it includes: a data transmission module 100, a supercapacitor 200, a conversion circuit 300, a switching circuit 400, a voltage regulator circuit 500, and a voltage monitoring circuit 600; wherein:

[0055] The conversion circuit 300 is connected to the switching circuit 400 and the supercapacitor 200 respectively, and is used to convert the external power supply VCC into the first DC power V1 and provide it to the switching circuit 400 and the supercapacitor 200.

[0056] Supercapacitor 200 is used for charging via a first DC current V1;

[0057] The switching circuit 400 is also connected to the supercapacitor 200 and the voltage regulator circuit 500 respectively. When the external power supply VCC is supplying power normally, it uses the first DC power V1 to provide the input voltage to the voltage regulator circuit 500; when the external power supply VCC is de-energized, it switches to using the supercapacitor 200 to provide the input voltage to the voltage regulator circuit 500.

[0058] The voltage regulator circuit 500 is connected to the data transmission module 100 and the voltage monitoring circuit 600 respectively, and is used to obtain the second DC voltage V2 by regulating the input voltage and supply it to the data transmission module 100 and the voltage monitoring circuit 600 for power supply.

[0059] The voltage monitoring circuit 600 is connected to the data transmission module 100 and is used to send a reset signal to the data transmission module 100 to reset the data transmission module 100 when the voltage of the second DC power V2 is lower than a preset voltage threshold.

[0060] The external power supply VCC is the main power source. The supercapacitor 200 is the backup power source.

[0061] The conversion circuit 300 can be connected to an external power supply VCC via a power connector to convert the external power supply VCC into the required first DC voltage V1. For example, the normal voltage of the first DC voltage V1 is 5V.

[0062] Under normal circumstances, the switching circuit 400 uses the first DC voltage V1 converted by the conversion circuit 300 to provide an input voltage to the voltage regulator circuit 500. The voltage regulator circuit 500 then regulates the input voltage to obtain a second DC voltage V2. The normal voltage of the second DC voltage V2 is the operating voltage of the data transmission module 100 and the voltage monitoring circuit 600. The voltage regulator circuit 500 provides the second DC voltage V2 to the voltage monitoring circuit 600 and the data transmission module 100, thus powering them. For example, the normal voltage of the second DC voltage V2 is 3.3V. Simultaneously, the first DC voltage V1 converted by the conversion circuit 300 also charges the supercapacitor 200. When the external power supply VCC fails, the switching circuit 400 can automatically, quickly, and seamlessly switch to using the supercapacitor 200 to provide an input voltage to the voltage regulator circuit 500, thereby maintaining power supply for a period of time. This allows the data transmission module 100 to save data in a timely manner, ensuring data integrity and security.

[0063] In practical applications, the data transmission module 100 can be used in electronic devices, which may include IoT industrial devices such as sensors, smart meters, and monitoring terminals.

[0064] The data transmission module 100 may include a controller and a storage unit connected to each other. For example, the controller is a microcontroller (MCU), such as an STM32F103 MCU. When the external power supply fails, the MCU is triggered to automatically save the data to the storage unit.

[0065] The preset voltage threshold is lower than the normal voltage of the second DC voltage V2. The specific value of the preset voltage threshold can be set according to actual needs, and is not specifically limited here.

[0066] The input terminal of the voltage monitoring circuit 600 is connected to the output terminal of the voltage regulator circuit 500, and the output terminal can be connected to the reset terminal of the controller. When the voltage of the second DC voltage V2 is detected to be lower than the preset voltage threshold, a reset signal is generated and sent to the controller to reset the controller. This prevents the controller from operating under low voltage and avoids abnormal operation, thus improving the stability and reliability of the controller operation.

[0067] The output of the voltage regulator circuit 500 can be connected to the power supply of the controller.

[0068] In this embodiment, an external power supply VCC provides the main power, and a supercapacitor 200 provides backup power. A switching circuit 400 switches between the external power supply VCC and the backup power. A conversion circuit 300 converts the external power supply VCC into a first DC current V1 and provides it to the switching circuit 400 and the supercapacitor 200. The supercapacitor 200 can be charged by the first DC current V1. When the external power supply VCC is working normally, the switching circuit 400 can use the first DC current V1 to provide input voltage to the voltage regulator circuit 500. When the external power supply VCC fails, the switching circuit 400 can switch to using the supercapacitor 200 to provide input voltage to the voltage regulator circuit 500. The voltage regulator circuit 500 obtains a second DC current V2 by regulating the input voltage and provides it to the data transmission module 100 and the voltage monitoring circuit 600. In this way, it can be ensured that even after the main power supply fails, it can still be powered by the backup power supply of the supercapacitor 200 for a period of time to save data in time, effectively preventing data loss and ensuring data integrity and security. Furthermore, a voltage monitoring circuit 600 monitors the voltage of the second DC power supply V2. When the voltage of the second DC power supply V2 is lower than a preset voltage threshold, a power outage may occur. At this time, a reset signal is sent to the data transmission module 100 to reset the data transmission module 100, thus avoiding abnormalities caused by the operation of the data transmission module 100 under low voltage. This achieves power outage protection, improves operational stability and reliability, and solves the problem that the addition of the supercapacitor 200 may cause abnormal operation of the data transmission module 100 due to the slower power outage process.

[0069] In addition, the power failure protection circuit of this embodiment integrates multiple functions such as power conversion, voltage monitoring, and automatic switching, which simplifies circuit design, reduces circuit complexity, facilitates installation and maintenance in practical applications, and has broad application prospects.

[0070] The power-loss protection circuit in this embodiment significantly improves the anti-interference capability under power fluctuation and power failure conditions, ensuring stable operation in various complex environments and higher reliability. It can meet the stringent requirements for data security and system stability in the fields of Internet of Things and industrial automation.

[0071] In some embodiments, such as Figure 2 As shown, the first input terminal of the switching circuit 400 is connected to the power output terminal of the conversion circuit 300, the second input terminal is connected to the first terminal of the supercapacitor 200, and the output terminal is connected to the input terminal of the voltage regulator circuit 500; the second terminal of the supercapacitor 200 is grounded.

[0072] The switching circuit 400 includes: a first switching transistor Q1, a second switching transistor Q2, a third switching transistor Q3, a first resistor R1, and a second resistor R2;

[0073] The gate of the first switching transistor Q1 is connected to the drain of the second switching transistor Q2 and the first end of the first resistor R1, the source is connected to the output of the switching circuit 400, and the drain is connected to the first input of the switching circuit 400.

[0074] The gate of the second switching transistor Q2 is connected to the first input terminal of the switching circuit 400, and its source is grounded.

[0075] The gate of the third switching transistor Q3 is connected to the first input terminal of the switching circuit 400 and the first terminal of the second resistor R2, respectively. The source is connected to the output terminal of the switching circuit 400, the first input terminal of the switching circuit 400 and the second terminal of the first resistor R1, respectively. The drain is connected to the second input terminal of the switching circuit 400.

[0076] The second terminal of the second resistor R2 is grounded.

[0077] In this design, the first switch Q1, the second switch Q2, and the third switch Q3 are MOSFETs. MOSFETs have a higher current draw and better current transfer performance. Of course, other switching transistors can also be used.

[0078] When the external power supply VCC is powered on, the conversion circuit 300 converts VCC into a first DC current V1. This first current charges the supercapacitor 200, while the second current is supplied to the switching circuit 400. In the switching circuit 400, due to the normal voltage of the first DC current V1, the second switch Q2 is turned on. After the second switch Q2 is turned on, the first switch Q1 is turned on. At this time, the switching circuit 400 can supply the first DC current V1 to the voltage regulator circuit 500 through the first switch Q1. When the external power supply VCC is de-energized, the voltage of the first DC current V1 becomes 0V. At this time, the second switch Q2 is not turned on, and therefore the first switch Q1 is also not turned on. The gate of the third switch Q3 is grounded through the second resistor R2, and the supercapacitor 200 is powered through the body diode of the third switch Q3. Therefore, the third switch Q3 is turned on, thus switching the switching circuit 400 to supply power to the voltage regulator circuit 500 using the supercapacitor 200.

[0079] In this embodiment, the switching circuit 400 is realized through the cooperation of the first switching transistor Q1, the second switching transistor Q2, the third switching transistor Q3, the first resistor R1, and the second resistor R2, which makes the switching circuit 400 respond faster and realize the rapid switching between the main power supply and the backup power supply when the power is lost.

[0080] The above is just an example of one structure of the switching circuit. Other structures can also be used, or the function of the switching circuit can be achieved by simple modifications based on this.

[0081] In some embodiments, such as Figure 2 As shown, the power failure protection circuit may also include: a pre-charging circuit 700; the conversion circuit 300 is connected to the supercapacitor 200 through the pre-charging circuit 700; the pre-charging circuit 700 is used to pre-charge the supercapacitor 200.

[0082] In practical applications, the supercapacitor 200 may generate a large inrush current during the charging process at the moment of power-on. If not controlled, this can easily trigger short-circuit protection and damage circuit components. Therefore, in this embodiment, a pre-charging circuit 700 is provided on the charging path of the supercapacitor 200. By pre-charging the supercapacitor 200 through the pre-charging circuit 700, damage to circuit components caused by excessive inrush current can be avoided.

[0083] In this circuit, the input terminal of the pre-charging circuit 700 is connected to the power output terminal of the conversion circuit 300, and the output terminal is connected to the first terminal of the supercapacitor 200; the second terminal of the supercapacitor 200 is grounded. For example, as shown... Figure 2As shown, the pre-charge circuit 700 includes: a diode D1 and a third resistor R3; the positive terminal of the diode D1 is connected to the input terminal of the pre-charge circuit 700, and the negative terminal is connected to the first terminal of the third resistor R3; the second terminal of the third resistor R3 is connected to the output terminal of the pre-charge circuit 700.

[0084] Among them, diode D1 can be a Schottky diode.

[0085] In this embodiment, a pre-charging circuit is formed by the third resistor R3 and the diode D1. The circuit structure is simple and more applicable. It not only effectively avoids the surge current at the moment of power-on and prevents short circuit protection caused by excessive current, but also protects circuit components from damage, extends circuit life, and improves reliability. Furthermore, since the diode is unidirectional, it can effectively prevent the supercapacitor 200 from flowing back to the conversion circuit 300 when discharging.

[0086] Of course, other pre-charging circuits can also be used, such as pre-charging circuits that only contain resistors, etc.

[0087] In some embodiments, such as Figure 3 As shown, the power status indicator terminal of the conversion circuit 300 is connected to the output terminal of the voltage regulator circuit 500 through the fourth resistor R4, and is also connected to the first input terminal of the data transmission module 100, for sending a power status indicator signal to the data transmission module 100.

[0088] The data transmission module 100 is used to trigger a data saving operation when the received power status indication signal indicates that the external power supply VCC has lost power.

[0089] The voltage at the power status indicator terminal of the conversion circuit 300 is pulled up to the voltage of the second DC power supply V2 through the fourth resistor R4. The power status indicator terminal of the conversion circuit 300 is connected to the first input terminal of the data transmission module 100 and is used to indicate the power status. Under normal external power supply VCC conditions, the power status indicator signal at the power status indicator terminal of the conversion circuit 300 is at a high level. When the external power supply VCC is de-energized, the power status indicator signal at the power status indicator terminal of the conversion circuit 300 is at a low level, triggering the data transmission module 100 to perform a data saving operation.

[0090] Specifically, the first input terminal of the data transmission module 100 is connected to the general purpose input / output (GPIO) terminal of the controller in the data transmission module 100. When the GPIO terminal of the controller receives a low-level power status indication signal, it automatically saves the data to the storage unit.

[0091] In this embodiment, by monitoring the power status, the data saving mechanism can be quickly triggered when the main power supply fails unexpectedly, ensuring that critical data is saved, effectively preventing data loss, and significantly improving data security.

[0092] In some embodiments, the power input terminal of the conversion circuit 300 is connected to the external power supply VCC, and the power output terminal is connected to the first terminal of the supercapacitor 200 and the first input terminal of the switching circuit 400, respectively.

[0093] like Figure 4 As shown, the conversion circuit 300 includes: a DC-DC converter chip U1, a Schottky diode D2, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a fifth resistor R5, a sixth resistor R6, and an inductor L.

[0094] The power input terminal VIN and enable terminal of the DCDC chip U1 are connected to the power input terminal of the conversion circuit 300, respectively. The bootstrap input terminal BOOT is connected to the first terminal of the first capacitor C1. The switching node SW is connected to the second terminal of the first capacitor C1, the cathode of the Schottky diode D2, and the first terminal of the inductor L, respectively. The feedback terminal FB is connected to the first terminal of the fifth resistor R5, the first terminal of the sixth resistor R6, and the first terminal of the second capacitor C2, respectively. The ground terminal GND is grounded.

[0095] The second terminal of the fifth resistor R5, the second terminal of the second capacitor C2, the first terminal of the third capacitor C3, the first terminal of the fourth capacitor C4, the first terminal of the fifth capacitor C5, and the second terminal of the inductor L are respectively connected to the power output terminal of the conversion circuit 300.

[0096] The positive terminal of Schottky diode D2, the second terminal of the third capacitor C3, the second terminal of the fourth capacitor C4, the second terminal of the fifth capacitor C5, and the second terminal of the sixth resistor R6 are all grounded.

[0097] For example, the DC-DC chip U1 is model SGM61630B. The SGM61630B has high conversion efficiency, minimizing energy loss and improving power supply efficiency. Based on this, the DC-DC chip U1 includes at least a power input terminal VIN and an enable terminal EN, a bootstrap input terminal BOOT, a switching node SW, a feedback terminal FB, a power status indicator terminal PG, a frequency control / synchronization terminal RT / SYNC, and a ground terminal GND.

[0098] The frequency control / synchronization terminal RT / SYNC of the DCDC chip U1 is grounded through the seventh resistor R7.

[0099] The power status indicator PG of the DC-DC chip U1 is the same as the power status indicator of the aforementioned conversion circuit 300.

[0100] The external power supply VCC is DC. The DC-DC chip U1 is responsible for converting the voltage of the external power supply VCC into a first DC voltage V1 that meets the required voltage and outputting it stably. Figure 5 As shown, the power status indicator terminal PG of the DC-DC chip U1 is pulled up to the voltage of the second DC power V2 through the fourth resistor R4 and connected to the first input terminal of the data transmission module 100. The first input terminal of the data transmission module 100 is connected to the general purpose input / output terminal GPIO of the controller 110. The power status indicator terminal PG of the DC-DC chip U1 is used to indicate the power status.

[0101] When the output of the DC-DC chip U1 is stable, the power status indicator terminal PG outputs a high level. When the external power supply VCC is abnormal, the power status indicator terminal PG is pulled low, triggering the controller 110 in the data transmission module 100 to perform a data saving operation and save the data to the storage unit 120.

[0102] The first DC power V1 output by the converter circuit 300 based on the DC-DC chip U1 supplies power to the voltage regulator circuit 500 through the switching circuit 400. At the same time, it charges the supercapacitor 200 so as to provide backup power to the voltage regulator circuit 500 when the main power supply fails.

[0103] In this embodiment, the external power supply VCC is converted by the DC-DC chip U1 and its peripheral circuits to make the conversion circuit 300 output a stable DC power.

[0104] The above is just an example of one structure of the conversion circuit. Other structures can also be used, or simple modifications can be made to achieve the function of the conversion circuit.

[0105] In some embodiments, such as Figure 5 As shown, the input terminal of the voltage regulator circuit 500 is connected to the output terminal of the switching circuit 400, and the output terminal is connected to the second input terminal of the data transmission module 100 and the input terminal of the voltage monitoring circuit 600, respectively.

[0106] The voltage regulator circuit 500 includes: a low-voltage linear regulator U2, an eighth resistor R8, a ninth resistor R9, and a sixth capacitor C6;

[0107] The power input terminal VIN of the low-voltage linear regulator U2 is connected to the input terminal of the voltage regulator circuit 500, and the power output terminal is connected to the output terminal of the voltage regulator circuit 500. The adjustable voltage terminal ADJ is connected to the output terminal of the voltage regulator circuit 500 through the eighth resistor R8 and grounded through the ninth resistor R9.

[0108] The first terminal of the sixth capacitor C6 is connected to the output terminal of the voltage regulator circuit 500, and the second terminal is grounded.

[0109] The low-voltage linear regulator U2 and its peripheral circuits can regulate the input voltage to obtain a stable DC output.

[0110] The low-voltage linear regulator U1 can be model SQ24301. The SQ24301 can operate under a wide input voltage range, thus adapting to various power supplies, offering greater versatility. It can also adjust the output voltage to meet specific voltage requirements. Based on this, the low-voltage linear regulator U1 includes a power input terminal VIN, an enable terminal EN, a first power output terminal OUT1, a second power output terminal OUT2, an adjustable voltage terminal ADJ, a ground terminal GND, and an exposed pad terminal EP.

[0111] The enable terminal EN of the low-voltage linear regulator U1 is connected to the input terminal of the voltage regulator circuit 500 through the tenth resistor R10, and is grounded through the eleventh resistor R11. The first power output terminal OUT1 and the second power output terminal OUT2 are both connected to the output terminal of the voltage regulator circuit 500. The ground terminal GND and the exposed pad terminal EP are both grounded.

[0112] In this embodiment, a low-voltage linear regulator is used to achieve voltage regulation, which can provide a stable output voltage with high precision and low ripple, and can respond quickly to changes in current. It can also output a stable voltage when the power supply is off.

[0113] The above is just an example of the structure of a voltage regulator circuit. Other structures can also be used, or simple modifications can be made to achieve the function of a voltage regulator circuit.

[0114] In some embodiments, such as Figure 5 As shown, the voltage monitoring circuit includes a voltage monitoring chip U3. The voltage monitoring chip U3 can be of the SGm706B model. The SGm706B is an integrated microprocessor monitoring chip that includes a reset output terminal RESET. When a power failure, watchdog timeout, or manual reset is detected, the RESET output terminal will output a low-level signal to reset the connected controller or other circuits, causing them to restart and return to normal operation.

[0115] The input terminal of the voltage monitoring circuit 600 is connected to the output terminal of the voltage regulator circuit 500, and the output terminal is connected to the second input terminal of the data transmission module 100. The third input terminal of the data transmission module 100 is connected to the output terminal of the voltage regulator circuit 500. The power supply terminal of the controller 110 is connected to the third input terminal of the data transmission module 100.

[0116] The power input terminal of the voltage monitoring chip U3 is connected to the input terminal of the voltage monitoring circuit 600, and the reset output terminal RESET is connected to the output terminal of the voltage monitoring circuit 600. This is used to generate a reset signal and send it to the data transmission module 100 when there is a power failure at the power input terminal.

[0117] The reset terminal NRST of the controller 110 is connected to the second input terminal of the data transmission module 100 and is used to perform a reset when a reset signal is received.

[0118] In this embodiment, voltage monitoring is achieved through a voltage monitoring chip, making the solution simpler to implement.

[0119] The above is just an example of the structure of a voltage monitoring circuit. Other structures can also be used, or simple modifications can be made to achieve the function of a voltage monitoring circuit.

[0120] It should be noted that the above-mentioned embodiments can be implemented in combination as needed.

[0121] This application also provides an electronic device including the power-off protection circuit described in the above embodiments. An external power source provides the main power, and a supercapacitor provides the backup power. A switching circuit switches between the external power source and the backup power source. The conversion circuit converts the external power source into a first DC current and supplies it to the switching circuit and the supercapacitor. The supercapacitor can be charged using the first DC current. When the external power source is operating normally, the switching circuit can use the first DC current to provide an input voltage to the voltage regulator circuit. When the external power source fails, the switching circuit switches to using the supercapacitor to provide an input voltage to the voltage regulator circuit. The voltage regulator circuit regulates the input voltage to obtain a second DC current and supplies it to the data transmission module and the voltage monitoring circuit. This ensures that even after the main power source fails, the supercapacitor can continue to supply power for a period of time to save data, effectively preventing data loss and ensuring data integrity and security. Furthermore, a voltage monitoring circuit is used to monitor the voltage of the second DC power supply. When the voltage of the second DC power supply is lower than the preset voltage threshold, a power outage may occur. At this time, a reset signal is sent to the data transmission module to reset the data transmission module, thus avoiding abnormalities caused by the data transmission module operating under low voltage and improving operational stability and reliability. Therefore, the problem of abnormal operation of the data transmission module caused by the slowed power-off process after adding a supercapacitor is solved.

[0122] For example, the electronic device is an Internet of Things (IoT) industrial device.

[0123] It should be understood that the terms "mechanism," "device," "component," etc., used in this application are merely one method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they can be replaced by other expressions.

[0124] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application. In practical applications, the technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification, and various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A power-off protection circuit, characterized in that, include: The circuit includes a data transmission module, a supercapacitor, a conversion circuit, a switching circuit, a voltage regulator circuit, and a voltage monitoring circuit; among which: The conversion circuit is connected to the switching circuit and the supercapacitor respectively, and is used to convert the external power supply into a first DC power and supply it to the switching circuit and the supercapacitor. The supercapacitor is used to be charged by the first DC current; The switching circuit is also connected to the supercapacitor and the voltage regulator circuit respectively, and is used to provide input voltage to the voltage regulator circuit using the first DC power when the external power supply is normal; and to switch to using the supercapacitor to provide input voltage to the voltage regulator circuit when the external power supply is off. The voltage regulator circuit is connected to the data transmission module and the voltage monitoring circuit respectively, and is used to obtain a second DC power by regulating the input voltage and provide it to the data transmission module and the voltage monitoring circuit for power supply; The voltage monitoring circuit is connected to the data transmission module and is used to send a reset signal to the data transmission module to reset the data transmission module when the voltage of the second DC power supply is lower than a preset voltage threshold.

2. The power-off protection circuit according to claim 1, characterized in that, The first input terminal of the switching circuit is connected to the power output terminal of the conversion circuit, the second input terminal is connected to the first terminal of the supercapacitor, and the output terminal is connected to the input terminal of the voltage regulator circuit; the second terminal of the supercapacitor is grounded. The switching circuit includes: a first switching transistor, a second switching transistor, a third switching transistor, a first resistor, and a second resistor; Wherein, the gate of the first switching transistor is connected to the drain of the second switching transistor and the first end of the first resistor, the source is connected to the output of the switching circuit, and the drain is connected to the first input of the switching circuit. The gate of the second switching transistor is connected to the first input terminal of the switching circuit, and its source is grounded; The gate of the third switching transistor is connected to the first input terminal of the switching circuit and the first terminal of the second resistor, the source is connected to the output terminal of the switching circuit, the first input terminal of the switching circuit and the second terminal of the first resistor, and the drain is connected to the second input terminal of the switching circuit. The second terminal of the second resistor is grounded.

3. The power-off protection circuit according to claim 2, characterized in that, The first switch, the second switch, and the third switch are MOSFETs.

4. The power-off protection circuit according to claim 1, characterized in that, Also includes: Pre-charging circuit; The conversion circuit is connected to the supercapacitor through the pre-charging circuit; The pre-charging circuit is used to pre-charge the supercapacitor.

5. The power-off protection circuit according to claim 4, characterized in that, The input terminal of the pre-charging circuit is connected to the power output terminal of the conversion circuit, and the output terminal is connected to the first terminal of the supercapacitor; the second terminal of the supercapacitor is grounded. The pre-charging circuit includes: a diode and a third resistor; The positive terminal of the diode is connected to the input terminal of the pre-charging circuit, and the negative terminal is connected to the first terminal of the third resistor. The second end of the third resistor is connected to the output end of the pre-charging circuit.

6. The power-off protection circuit according to claim 1, characterized in that, The power status indicator terminal of the conversion circuit is connected to the output terminal of the voltage regulator circuit through a fourth resistor, and is also connected to the first input terminal of the data transmission module, for sending a power status indicator signal to the data transmission module. The data transmission module is used to trigger a data saving operation when the received power status indication signal indicates that the external power supply has failed.

7. The power-off protection circuit according to claim 1, characterized in that, The power input terminal of the conversion circuit is connected to the external power source, and the power output terminal is connected to the first terminal of the supercapacitor and the first input terminal of the switching circuit, respectively. The conversion circuit includes: a DC-DC chip, a Schottky diode, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a fifth resistor, a sixth resistor, and an inductor; The power input terminal and enable terminal of the DC-DC chip are respectively connected to the power input terminal of the conversion circuit, the bootstrap input terminal is connected to the first terminal of the first capacitor, the switching node is respectively connected to the second terminal of the first capacitor, the negative terminal of the Schottky diode, and the first terminal of the inductor, the feedback terminal is respectively connected to the first terminal of the fifth resistor, the first terminal of the sixth resistor, and the first terminal of the second capacitor, and the ground terminal is grounded. The second terminal of the fifth resistor, the second terminal of the second capacitor, the first terminal of the third capacitor, the first terminal of the fourth capacitor, the first terminal of the fifth capacitor, and the second terminal of the inductor are respectively connected to the power output terminal of the conversion circuit. The positive terminal of the Schottky diode, the second terminal of the third capacitor, the second terminal of the fourth capacitor, the second terminal of the fifth capacitor, and the second terminal of the sixth resistor are all grounded.

8. The power-off protection circuit according to claim 1, characterized in that, The input terminal of the voltage regulator circuit is connected to the output terminal of the switching circuit, and the output terminal is connected to the second input terminal of the data transmission module and the input terminal of the voltage monitoring circuit, respectively. The voltage regulator circuit includes: a low-voltage linear regulator, an eighth resistor, a ninth resistor, and a sixth capacitor; The power input terminal of the low-voltage linear regulator is connected to the input terminal of the voltage regulator circuit, the power output terminal is connected to the output terminal of the voltage regulator circuit, and the adjustable voltage terminal is connected to the output terminal of the voltage regulator circuit through the eighth resistor and grounded through the ninth resistor. The first terminal of the sixth capacitor is connected to the output terminal of the voltage regulator circuit, and the second terminal is grounded.

9. An electronic device, characterized in that, Includes the power failure protection circuit as described in any one of claims 1 to 8.

10. The electronic device according to claim 9, characterized in that, The electronic device is an IoT industrial device.

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