Undervoltage protection circuit and undervoltage protection method

Abstract

The embodiment of the invention relates to the technical field of circuit design, and discloses an under-voltage protection circuit and an under-voltage protection method, and the under-voltage protection circuit comprises a partial voltage sampling unit, a reference voltage device, a bias current providing unit and a switch unit. The input end of the voltage division sampling unit is connected with a voltage detection node of the main circuit, and the voltage division sampling unit is used for obtaining input voltage, dividing the input voltage and outputting the divided voltage to the reference voltage device; the output end of the reference voltage device is connected with the input end of the switch unit; under the condition that the first voltage input to the reference voltage device is not greater than the second voltage of the reference voltage device, the reference voltage device is in a non-conducting state, and the bias current supply unit obtains current from a power supply node of the main circuit and inputs bias current to the switch unit; the output end of the switch unit is connected with a control node of the main circuit, after the bias current is obtained, an under-voltage protection signal of the main circuit is output, and the under-voltage protection signal is used for controlling the main circuit to stop working so as to protect the main circuit from being damaged.

Description

Technical Field

[0001] The present application relates to the technical field of circuit design, and in particular to an undervoltage protection circuit and an undervoltage protection method. Background Art

[0002] During the normal operation of the driver, if the grid voltage fluctuates, such as when the input voltage drops, the circuit may experience undervoltage. Undervoltage refers to the power supply voltage being lower than the minimum voltage required for the normal operation of the device. When the circuit is in an undervoltage state, the electronic components of the driver will be damaged. Summary of the invention

[0003] The embodiment of the present application provides an undervoltage protection circuit to solve the problem in the prior art that the driver circuit voltage is prone to undervoltage.

[0004] In order to solve the above problems, the embodiment of the present application discloses an undervoltage protection circuit, including: a voltage division sampling unit, a reference voltage device, a bias current providing unit and a switch unit; The voltage-dividing sampling unit comprises: a first resistor and a second resistor connected in series; The input end of the voltage division sampling unit is connected to the voltage detection node of the main circuit, and is used to obtain the input voltage, and output the input voltage to the reference voltage device after voltage division; The output end of the reference voltage device is connected to the input end of the switch unit; Wherein, when the first voltage input to the reference voltage device is not greater than the second voltage of the reference voltage device, the reference voltage device is in a non-conducting state, and the bias current providing unit obtains current from the power supply node of the main circuit and inputs the bias current to the switch unit; The output end of the switch unit is connected to the control node of the main circuit, and after acquiring the bias current, outputs an undervoltage protection signal of the main circuit, wherein the undervoltage protection signal is used to control the main circuit to stop working.

[0005] The embodiment of the present application further discloses an undervoltage protection method, which is applied to the above undervoltage protection circuit, and the method includes: When it is detected that the first voltage output by the voltage-dividing sampling unit is not greater than the second voltage of the reference voltage device, the reference voltage device is switched from a conducting state to a non-conducting state; The switch unit obtains the bias current through the bias current providing unit, and outputs an undervoltage protection signal of the main circuit, wherein the undervoltage protection signal is used to control the main circuit to stop working.

[0006] The present application also discloses an undervoltage protection device, which includes: A first processing module, configured to switch the reference voltage device from a conducting state to a non-conducting state when it is detected that the first voltage output by the voltage-dividing sampling unit is not greater than the second voltage of the reference voltage device; The second processing module is used for the switch unit to obtain the bias current through the bias current providing unit, and output the undervoltage protection signal of the main circuit, wherein the undervoltage protection signal is used to control the main circuit to stop working.

[0007] An embodiment of the present application also discloses an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, one or more of the methods described in the embodiments of the present application are implemented.

[0008] The embodiments of the present application further disclose a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, one or more methods described in the embodiments of the present application are implemented.

[0009] The embodiments of the present application also disclose a computer program product, including a computer program, which, when executed by a processor, implements one or more of the methods described in the embodiments of the present application.

[0010] It can be seen from the above technical solution that the embodiment of the present application forms a voltage divider network by connecting the first resistor and the second resistor in series, and divides the input voltage from the power supply voltage and inputs it into the reference voltage device. When the input voltage drops, the voltage after voltage division will also drop, and the reference voltage device compares the first voltage after voltage division with the reference voltage (second voltage). If the first voltage is not greater than the second voltage, the reference voltage device is in a non-conducting state. When the reference voltage device is in a non-conducting state, the switching unit obtains the bias current through the bias current providing unit, and after obtaining the bias current, outputs the undervoltage protection signal of the main circuit, and the undervoltage protection signal is used to control the main circuit to stop working, so as to avoid damage to the components of the main circuit due to undervoltage.

[0011] Additional aspects and advantages of the embodiments of the present application will be partially given in the description below, which will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 One of the structural schematic diagrams of the undervoltage protection circuit provided in the embodiment of the present application; Figure 2 The second structural diagram of the undervoltage protection circuit provided in the embodiment of the present application; Figure 3 The third structural diagram of the undervoltage protection circuit provided in the embodiment of the present application; Figure 4 One of the flow charts of the undervoltage protection method provided in the embodiment of the present application; Figure 5 The second flowchart of the undervoltage protection method provided in the embodiment of the present application; Figure 6 Flow chart 3 of the undervoltage protection method provided in the embodiment of the present application; Figure 7 A schematic diagram of the structure of an undervoltage protection device provided in an embodiment of the present application; Figure 8 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0013] The embodiments of the present application are described below in conjunction with the drawings in the present application. It should be understood that the implementation methods described below in conjunction with the drawings are exemplary descriptions for explaining the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions of the embodiments of the present application.

[0014] Those skilled in the art will appreciate that, unless specifically stated, the singular forms "one", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the terms "including" and "comprising" used in the embodiments of the present application refer to that the corresponding features can be implemented as the presented features, information, data, steps, operations, elements and / or components, but do not exclude the implementation as other features, information, data, steps, operations, elements, components and / or combinations thereof supported by the technical field. It should be understood that when we say that an element is "connected" or "coupled" to another element, the one element may be directly connected or coupled to the other element, or it may refer to that the one element and the other element establish a connection relationship through an intermediate element. In addition, the "connection" or "coupling" used here may include wireless connection or wireless coupling. The term "multiple" refers to two or more than two. In view of this, "multiple" may also be understood as "at least two" in the embodiments of the present application. The term "and / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / ", unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship.

[0015] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0016] The undervoltage protection circuit provided in the embodiment of the present application is widely used in various electronic devices and industrial control systems that require a stable power supply, and is particularly suitable for occasions with large voltage fluctuations, such as household appliances, automation equipment, drivers, communication equipment, and other high-precision control systems. During the operation of these devices, the fluctuation or drop in input voltage may cause damage to electronic components, affect the normal operation of the equipment, and even bring potential safety hazards. Through the undervoltage protection circuit of the embodiment of the present application, when the input voltage is lower than the set undervoltage point, the circuit can automatically trigger the protection mechanism, cut off the power supply or stop the operation of the equipment in time, and avoid overheating, burning or other device damage caused by low voltage.

[0017] For example, in industrial automation systems, the driver is usually responsible for controlling the start and operation of the motor. If the input voltage is unstable, especially when the grid voltage fluctuates or the battery voltage is too low, the driver may not work properly or even damage sensitive electronic components. The undervoltage protection circuit of the embodiment of the present application can effectively prevent this from happening, ensuring that the system can shut down safely when the voltage is abnormal, reducing equipment failures and maintenance costs.

[0018] In addition, this circuit is also suitable for battery-powered portable devices, ensuring that the device automatically enters protection mode when the battery power is too low, extending the battery life and avoiding functional abnormalities caused by low voltage. By adjusting the voltage divider resistor in the circuit, users can flexibly set the undervoltage protection point to adapt to different voltage requirements, thereby achieving more accurate and reliable power protection.

[0019] Figure 1 FIG. 1 is one of the structural diagrams of the undervoltage protection circuit according to the embodiment of the present application. Figure 1 The undervoltage protection circuit provided in the embodiment of the present application is explained and illustrated in detail. Figure 1 As shown, the undervoltage protection circuit includes: a voltage division sampling unit 1, a reference voltage device 2, a switch unit 3 and a bias current providing unit 4.

[0020] The undervoltage protection circuit provided in the embodiment of the present application includes: a voltage division sampling unit 1, a reference voltage device 2, a bias current providing unit 4 and a switch unit 3; The voltage-dividing sampling unit 1 comprises: a first resistor and a second resistor connected in series; The input end of the voltage-dividing sampling unit 1 is connected to the voltage detection node of the main circuit, and is used to obtain the input voltage, and output the input voltage to the reference voltage device 2 after voltage division; The output end of the reference voltage device 2 is connected to the input end of the switch unit 3; Wherein, when the first voltage input to the reference voltage device 2 is not greater than the second voltage of the reference voltage device 2, the reference voltage device 2 is in a non-conducting state, and the bias current providing unit 4 obtains current from the power supply node of the main circuit and inputs the bias current to the switch unit 3; The output end of the switch unit 3 is connected to the control node of the main circuit, and after acquiring the bias current, outputs an undervoltage protection signal of the main circuit, wherein the undervoltage protection signal is used to control the main circuit to stop working.

[0021] The undervoltage protection circuit provided in the embodiment of the present application is intended to solve the technical problem that the input voltage drop or voltage fluctuation may cause equipment damage and abnormal operation. In modern electronic equipment, the stability of the power supply voltage is crucial to the normal operation of the system, especially for high-precision and high-reliability equipment such as drivers, motors, and communication equipment. If the voltage is lower than the minimum operating voltage required by the device, it may cause the device to fail to start normally, and even cause damage to electronic components. Existing voltage protection schemes usually rely on external components for overvoltage or undervoltage protection, but these schemes have high costs and complex adjustment problems. The undervoltage protection circuit proposed in the present application effectively solves this problem through precise voltage sampling, reference voltage comparison and automatic control mechanism, ensuring that the device can automatically disconnect or stop working when the input voltage is abnormal, avoiding equipment damage.

[0022] Specifically, the undervoltage protection circuit provided in the embodiment of the present application includes a voltage division sampling unit, which is used to convert the input voltage into a voltage value suitable for subsequent circuit processing through voltage division. The voltage division sampling unit is composed of a first resistor and a second resistor in series, and the input end of the voltage division sampling unit is connected to the voltage detection node of the main circuit to receive the input voltage of the main circuit. By adjusting the resistance of the resistor, the user can control the ratio of the voltage division. For example, the voltage value after voltage division can be equal to the voltage value of the input voltage multiplied by the resistance value of the second resistor, and then divided by the sum of the resistance values ​​of the first resistor and the second resistor. Among them, the resistance value of the first resistor and the second resistor determines the relationship between the input voltage and the voltage output by the voltage division sampling unit. For example, the input voltage will output a lower voltage value after the series voltage division of the two resistors. This voltage after voltage division will be sent to the subsequent reference voltage device as an input signal compared with the reference voltage. In this way, the voltage division sampling unit can achieve accurate sampling of the input voltage and provide the required voltage reference value for the subsequent protection mechanism.

[0023] Furthermore, the main function of the reference voltage device is to compare the voltage after voltage division with the reference voltage. If the voltage after voltage division is not greater than the reference voltage, it indicates that the voltage value of the current input voltage is too low, and the circuit needs to be protected in time to avoid damage to components. Among them, the reference voltage of the reference voltage device is the reference voltage value used by the device to judge the voltage state of the voltage input of the voltage division sampling unit. The reference voltage represents the minimum allowable value or threshold of the input voltage in the undervoltage protection circuit. When the input voltage (or the voltage after voltage division sampling) is lower than this reference voltage, the reference voltage device will enter a non-conducting state. When the reference voltage device is in a non-conducting state, it will not provide a signal to the switch unit, thereby triggering the subsequent protection mechanism. By setting a suitable reference voltage, the trigger point of the undervoltage protection circuit can be accurately controlled to ensure that the circuit can respond in time when the voltage is insufficient, while avoiding false triggering.

[0024] Furthermore, the reference voltage device will not provide a signal to the switch unit in the non-conducting state. At this time, the bias current providing unit will obtain current through the power supply node of the main circuit and input an appropriate bias current to the switch unit. Among them, after receiving the bias current, the switch unit outputs an undervoltage protection signal, and the main circuit can take corresponding protection measures according to the undervoltage protection signal. For example, stop working or cut off the power supply to prevent the components in the main circuit from continuing to operate when the input voltage is too low. Among them, the main circuit can be a secondary circuit. The undervoltage protection circuit provided in the embodiment of the present application effectively solves the problem of equipment failure caused by voltage abnormality through precise voltage division, reference voltage comparison, bias current supply and switch unit control, and provides an efficient, flexible and low-cost undervoltage protection solution.

[0025] Figure 2 FIG. 2 is a second structural diagram of an undervoltage protection circuit according to an embodiment of the present application. Figure 2 As shown, the undervoltage protection circuit shown in the embodiment of the present application includes: a voltage detection node (Alternating Current Switch, ACS), a first resistor R1, a second resistor R2, a filter capacitor C1, a reference voltage device U1, a third resistor R3, a diode D1, a fourth resistor R4, and a switch unit Q1.

[0026] In the embodiment of the present application, one end of R1 is connected to ACS, and the other end is connected to R2; C1 is connected in parallel to both ends of R2; the input end of U1 is connected to R2, and the output end is connected to the base of Q1 through D1; one end of R3 is connected to the power supply node of the main circuit, and the other end is connected to the base of Q1 through D1; one end of R4 is connected to the base of Q1, and the other end is grounded; the output end of Q1 is connected to the control node of the main circuit, for example, the output end of Q1 is connected to the comparator input (Comparator, COMP) pin of the control chip of the main circuit.

[0027] Specifically, R1 and R2 are used to divide the voltage output by ACS and output the divided voltage to U1; C1 is used to filter or stabilize the voltage signal after the voltage division; U1 is used to compare the divided voltage output by R1 and R2 with the reference voltage. When the divided voltage is greater than the reference voltage, U1 is turned on and provides a low level to the base of Q1 through D1. Q1 is in a non-conducting state. At this time, R3 does not output bias current and the main circuit works normally; when the divided voltage is less than or equal to the reference voltage, U1 is in a non-conducting state (or called U1 cut-off). At this time, R3 provides a high level to the base of Q1 through D1, Q1 is turned on, and the potential of the COMP pin of the control chip of the main circuit is pulled down, causing the circuit to enter the hiccup protection mode, thereby achieving the purpose of undervoltage protection. Among them, in the circuit, the hiccup protection mode (commonly referred to as "breathing protection" or "protection mode") is a protection mechanism used to prevent the circuit from being damaged due to abnormal voltage or current problems. Specifically, the hiccup protection mode is usually used to prevent the circuit from continuing to work under undervoltage, overvoltage, overcurrent or other abnormal conditions to avoid damage to circuit components. It will temporarily cut off or limit the normal operation of the circuit until the circuit returns to normal.

[0028] In some embodiments, the reference voltage device includes at least one of the following: Reference voltage comparator, Zener diode.

[0029] In an embodiment of the present application, the reference voltage device can be a reference voltage comparator or a voltage zener diode, which is used to receive the voltage after voltage division by R1 and R2. When the voltage after voltage division is greater than the reference voltage of the reference voltage device, the reference voltage device is in a conductive state; when the voltage after voltage division is less than or equal to the reference voltage of the reference voltage device, the reference voltage device is in a non-conductive state.

[0030] In some embodiments, the switch unit is a voltage-controlled device for controlling the output state (on or off of the collector to emitter) according to an input signal (such as a base voltage). Typically, it can be a metal-oxide-semiconductor field-effect transistor (MOSFET).

[0031] Figure 3 FIG. 3 is a third structural diagram of an undervoltage protection circuit according to an embodiment of the present application. Figure 2 As shown, the undervoltage protection circuit shown in the embodiment of the present application includes: a first resistor R1, a second resistor R2, a filter capacitor C1, a reference voltage device U1, a third resistor R3, a switch unit Q1, a fourth resistor R4, and a diode D1.

[0032] In the embodiment of the present application, one end of R1 is connected to a voltage source, and the other end is connected to R2; C1 is connected in parallel to both ends of R2; the input end of U1 is connected to R2, and the output end is connected to the base of Q1 through R4; one end of R3 is connected to the base of Q1, and the other end is connected to the emitter of Q1, acting as a bias resistor; the output end of Q1 is connected to the control node of the main circuit through D1, for example, the output end of Q1 is connected to the power pin (Voltage Common Collector, VCC) of the control chip of the main circuit.

[0033] Specifically, R1 and R2 are used to divide the voltage output by the voltage source and output the divided voltage to U1; C1 is used to filter or stabilize the voltage signal after the voltage division; U1 is used to compare the divided voltage output by R1 and R2 with the reference voltage. When the divided voltage is greater than the reference voltage, U1 is turned on and provides a low level to the base of Q1 through R4. Q1 is turned on and Q1 provides voltage to the VDD pin of the control chip of the main circuit through D1. At this time, R3 does not output bias current and the main circuit works normally. When the divided voltage is less than or equal to the reference voltage, U1 is in a non-conducting state (or called U1 cut-off), the base of Q1 obtains bias current through R3 and R4, and Q1 is in a non-conducting state, resulting in the VDD pin of the control chip of the main circuit having no power supply, causing the main circuit to stop working, thereby achieving the purpose of undervoltage protection.

[0034] In some embodiments, in some embodiments, the reference voltage device includes at least one of the following: Reference voltage comparator, Zener diode.

[0035] In an embodiment of the present application, the reference voltage device can be a reference voltage comparator or a voltage zener diode, which is used to receive the voltage after voltage division by R1 and R2. When the voltage after voltage division is greater than the reference voltage of the reference voltage device, the reference voltage device is in a conductive state; when the voltage after voltage division is less than or equal to the reference voltage of the reference voltage device, the reference voltage device is in a non-conductive state.

[0036] In some embodiments, the switch unit is a current-controlled device. For example, the switch unit may be a positive-negative-positive transistor (PNP), which is turned on at a low level and turned off at a high level.

[0037] The present application also provides an undervoltage protection method. Figure 4 One of the flow charts of the undervoltage protection method provided in the embodiment of the present application is shown in FIG. Figure 4 , the method may include the following steps: Step 401 : When it is detected that the first voltage output by the voltage-dividing sampling unit is not greater than the second voltage of the reference voltage device, the reference voltage device is switched from a conducting state to a non-conducting state.

[0038] In an embodiment of the present application, when it is detected that the first voltage obtained by the voltage-dividing sampling unit (i.e., the voltage after the input voltage is divided) is not greater than the second voltage of the reference voltage device, the reference voltage device will switch from the conducting state to the non-conducting state. Here, the reference voltage device is usually a device with a fixed reference voltage output (such as a voltage-stabilizing diode or a comparator), and its function is to monitor the voltage after the voltage division and compare it with a predetermined reference voltage. If the input voltage drops to a certain threshold, causing the first voltage to be lower than or equal to the second voltage, the reference voltage device will disconnect, indicating that the circuit is in an undervoltage state. This process can effectively determine whether the voltage has reached the undervoltage condition, and the operation is simple and reliable.

[0039] Step 402: the switch unit obtains the bias current through the bias current providing unit, and outputs an undervoltage protection signal of the main circuit, wherein the undervoltage protection signal is used to control the main circuit to stop working.

[0040] In the embodiment of the present application, the switch unit obtains the bias current through the bias current providing unit, thereby outputting an undervoltage protection signal to control the main circuit to stop working. Specifically, the switch unit will be controlled according to the change of the state of the reference voltage device. When the reference voltage device is not conducting, the switch unit generates an undervoltage protection signal to notify the main circuit to enter the undervoltage protection mode and stop the circuit from working to avoid circuit instability or damage due to low voltage. In this way, the circuit can respond in time and protect the subsequent circuit from undervoltage.

[0041] Figure 5 This is the second flow chart of the undervoltage protection method provided in the embodiment of the present application. Figure 5 As shown, the undervoltage protection method provided by the embodiment of the present application includes: Step 501 : When it is detected that the first voltage output by the voltage-dividing sampling unit is not greater than the second voltage of the reference voltage device, the reference voltage device is switched from a conducting state to a non-conducting state.

[0042] In an embodiment of the present application, when it is detected that the first voltage obtained by the voltage-dividing sampling unit (i.e., the voltage after the input voltage is divided) is not greater than the second voltage of the reference voltage device, the reference voltage device will switch from the conducting state to the non-conducting state. Here, the reference voltage device is usually a device with a fixed reference voltage output (such as a voltage-stabilizing diode or a comparator), and its function is to monitor the voltage after the voltage division and compare it with a predetermined reference voltage. If the input voltage drops to a certain threshold, causing the first voltage to be lower than or equal to the second voltage, the reference voltage device will disconnect, indicating that the circuit is in an undervoltage state. This process can effectively determine whether the voltage has reached the undervoltage condition, and the operation is simple and reliable.

[0043] Step 502: the switch unit obtains a bias current through the bias current providing unit, and after obtaining the bias current, switches from a non-conducting state to a conducting state to control the main circuit to enter a hiccup protection mode.

[0044] In an embodiment of the present application, the switch unit is a voltage-controlled device, such as a MOS tube. The switch unit obtains the bias current through the bias current providing unit, and after obtaining the bias current, switches from a non-conducting state to a conducting state. This means that when the bias current passes through the switch unit, the gate or base voltage of the switch unit is appropriately adjusted, so that the switch unit switches from a non-conducting state to a conducting state. At this time, the switch unit starts to conduct, thereby controlling the main circuit to enter the hiccup protection mode. In this mode, the main circuit is forced to stop working to prevent damage to the circuit due to problems such as unstable, too high or too low voltage. In this way, the main circuit can automatically enter the protection state when the input voltage is low. The embodiment of the present application ensures that the system can respond quickly and switch to the hiccup protection mode when the voltage is abnormal, preventing the circuit from being damaged due to an unstable state. This operation is reliable and automated, and can effectively improve the safety and protection capabilities of the system and avoid potential hardware failures.

[0045] In some embodiments, the method further comprises: When it is detected that the first voltage output by the voltage-dividing sampling unit is greater than the second voltage of the reference voltage device, the reference voltage device is switched from a non-conducting state to a conducting state; After the reference voltage device is turned on, the potential of the input terminal of the switch unit is reduced, so that the switch unit is switched from a conducting state to a non-conducting state; After the switch unit is switched to the non-conducting state, the potential of the control node of the main circuit returns to normal, and the main circuit returns to the working state.

[0046] In an embodiment of the present application, when it is detected that the first voltage output by the voltage-dividing sampling unit is greater than the second voltage of the reference voltage device, it indicates that the magnitude of the input voltage has returned to normal. At this time, the reference voltage device switches from a non-conducting state to a conducting state. After the reference voltage device is turned on, the base level of the switch unit is pulled down, causing the switch unit to be in a non-conducting state. Since the switch unit is non-conducting, the potential of the control node of the main circuit is restored to normal, and the main circuit returns to a normal working state. This process ensures that when the input voltage returns to a normal level, the circuit can resume normal operation and avoid entering a protection mode, thereby maintaining the stability and continuous operation of the circuit. The embodiment of the present application can realize automatic recovery of the circuit state, ensuring that when the voltage returns to a safe range, the circuit can self-restore to a normal working state, avoiding the need for human intervention, and improving the reliability and adaptability of the system.

[0047] Figure 6 This is the third flow chart of the undervoltage protection method provided in the embodiment of the present application. Figure 6 As shown, the undervoltage protection method provided by the embodiment of the present application includes: Step 601 : when it is detected that the first voltage output by the voltage-dividing sampling unit is not greater than the second voltage of the reference voltage device, the reference voltage device is switched from a conducting state to a non-conducting state.

[0048] In an embodiment of the present application, when it is detected that the first voltage obtained by the voltage-dividing sampling unit (i.e., the voltage after the input voltage is divided) is not greater than the second voltage of the reference voltage device, the reference voltage device will switch from the conducting state to the non-conducting state. Here, the reference voltage device is usually a device with a fixed reference voltage output (such as a voltage-stabilizing diode or a comparator), and its function is to monitor the voltage after the voltage division and compare it with a predetermined reference voltage. If the input voltage drops to a certain threshold, causing the first voltage to be lower than or equal to the second voltage, the reference voltage device will disconnect, indicating that the circuit is in an undervoltage state. This process can effectively determine whether the voltage has reached the undervoltage condition, and the operation is simple and reliable.

[0049] Step 602: the switch unit obtains a bias current through the bias current providing unit, and after obtaining the bias current, switches from a conducting state to a non-conducting state, and stops supplying power to the main circuit.

[0050] In an embodiment of the present application, the switch unit is a current-controlled device, such as a PNP tube. When the switch unit obtains the bias current through the bias current providing unit, the switch unit switches from the conducting state to the non-conducting state. This switching process means that the switch unit stops conducting, thereby interrupting the power supply to the main circuit. In this way, the main circuit can automatically enter the protection state when the input voltage is low, preventing the circuit from being damaged due to an unstable state, thereby improving the durability and reliability of the circuit.

[0051] In some embodiments, the method further comprises: When it is detected that the first voltage output by the voltage-dividing sampling unit is greater than the second voltage of the reference voltage device, the reference voltage device is switched from a non-conducting state to a conducting state; After the reference voltage device is turned on, the potential of the input terminal of the switch unit is reduced, so that the switch unit is switched from a non-conducting state to a conducting state; After the switch unit is switched to the on state, the main circuit starts to be supplied with power.

[0052] In an embodiment of the present application, when it is detected that the first voltage output by the voltage-dividing sampling unit is greater than the second voltage of the reference voltage device, it indicates that the magnitude of the input voltage has returned to normal. The reference voltage device switches from a non-conducting state to a conducting state. After the reference voltage device is turned on, it lowers the potential at the input end of the switch unit, causing the base of the switch unit to produce a low level. At this time, the switch unit switches from a non-conducting state to a conducting state. Once the switch unit is turned on, it starts to provide power to the main circuit and restores the normal operation of the main circuit. This process usually occurs when the voltage returns to a normal level, ensuring that the circuit can operate normally when the voltage is sufficient. In this embodiment of the present application, through this automatic control method, when the voltage returns to a safe operating range, the circuit can self-recover, avoiding human intervention. This operation ensures the stability and continuity of the system, while reducing potential damage caused by voltage instability, which helps to improve the reliability and adaptability of the system.

[0053] Based on the same principle as the method provided in the embodiment of the present application, the embodiment of the present application also provides an undervoltage protection device, such as Figure 7 As shown, the device comprises: A first processing module 1 is used for switching the reference voltage device from a conducting state to a non-conducting state when it is detected that the first voltage output by the voltage-dividing sampling unit is not greater than the second voltage of the reference voltage device; The second processing module 2 is used for the switch unit to obtain the bias current through the bias current providing unit, and output the undervoltage protection signal of the main circuit, wherein the undervoltage protection signal is used to control the main circuit to stop working.

[0054] The undervoltage protection device provided in the embodiment of the present application can achieve Figures 4 to 6 To avoid repetition, the various processes implemented in the method embodiment are not described here.

[0055] The undervoltage protection device provided by the present application forms a voltage divider network by connecting a first resistor and a second resistor in series, divides the input voltage from the power supply voltage, and inputs it into a reference voltage device. When the input voltage drops, the divided voltage will also drop, and the reference voltage device compares the divided first voltage with the reference voltage (second voltage). If the first voltage is not greater than the second voltage, the reference voltage device is in a non-conducting state. When the reference voltage device is in a non-conducting state, the switch unit obtains the bias current through the bias current providing unit, and after obtaining the bias current, outputs the undervoltage protection signal of the main circuit, and the undervoltage protection signal is used to control the main circuit to stop working, so as to avoid damage to the components of the main circuit due to undervoltage.

[0056] The undervoltage protection device of the embodiment of the present application can execute the undervoltage protection method provided in the embodiment of the present application, and the implementation principle is similar. The actions performed by each module and unit in the undervoltage protection device in each embodiment of the present application correspond to the steps in the undervoltage protection method in each embodiment of the present application. For the detailed functional description of each module of the undervoltage protection device, please refer to the description in the corresponding undervoltage protection method shown in the previous text, which will not be repeated here.

[0057] Based on the same principle as the method shown in the embodiment of the present application, the embodiment of the present application also provides an electronic device, which may include but is not limited to: a processor and a memory; a memory for storing a computer program; a processor for executing the undervoltage protection method shown in any optional embodiment of the present application by calling a computer program. Compared with the prior art, the undervoltage protection method provided by the present application forms a voltage divider network by connecting a first resistor and a second resistor in series, and divides the input voltage from the power supply voltage and inputs it into the reference voltage device. When the input voltage drops, the divided voltage will also drop, and the reference voltage device compares the divided first voltage with the reference voltage (second voltage). If the first voltage is not greater than the second voltage, the reference voltage device is in a non-conducting state. When the reference voltage device is in a non-conducting state, the switch unit obtains the bias current through the bias current providing unit, and after obtaining the bias current, outputs the undervoltage protection signal of the main circuit, and the undervoltage protection signal is used to control the main circuit to stop working to avoid damage to the components of the main circuit due to undervoltage.

[0058] In an optional embodiment, an electronic device is also provided, such as Figure 8 As shown, Figure 8The electronic device 8000 shown includes: a processor 8001 and a memory 8003. The processor 8001 and the memory 8003 are connected, such as through a bus 8002. Optionally, the electronic device 8000 may also include a transceiver 8004, which may be used for data interaction between the electronic device and other electronic devices, such as data transmission and / or data reception. It should be noted that in actual applications, the transceiver 8004 is not limited to one, and the structure of the electronic device 8000 does not constitute a limitation on the embodiments of the present application.

[0059] The processor 8001 may be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. It may implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of this application. The processor 8001 may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0060] The bus 8002 may include a path to transmit information between the above components. The bus 8002 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus. The bus 8002 may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 8 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0061] The memory 8003 may be a ROM (Read Only Memory) or other types of static storage devices that can store static information and instructions, a RAM (Random Access Memory) or other types of dynamic storage devices that can store information and instructions, or an EEPROM (Electrically Erasable Programmable Read Only Memory), a CD-ROM (Compact Disc Read Only Memory) or other optical disk storage, optical disk storage (including compressed optical disk, laser disk, optical disk, digital versatile disk, Blu-ray disk, etc.), magnetic disk storage medium, other magnetic storage devices, or any other medium that can be used to carry or store computer programs and can be read by a computer, without limitation herein.

[0062] The memory 8003 is used to store the computer program for executing the embodiment of the present application, and the execution is controlled by the processor 8001. The processor 8001 is used to execute the computer program stored in the memory 8003 to implement the steps shown in the above method embodiment.

[0063] Among them, electronic devices include but are not limited to: mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 8 The electronic device shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0064] An embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps and corresponding contents of the aforementioned method embodiment can be implemented.

[0065] The embodiment of the present application also provides a computer program product, including a computer program, which can implement the steps and corresponding contents of the aforementioned method embodiment when executed by a processor.

[0066] The terms "first", "second", "third", "fourth", "1", "2", etc. (if any) in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that shown or described in the drawings.

[0067] It should be understood that, although each operation step is indicated by arrows in the flowchart of the embodiment of the present application, the implementation order of these steps is not limited to the order indicated by the arrows. Unless clearly stated herein, in some implementation scenarios of the embodiment of the present application, the implementation steps in each flowchart can be performed in other orders according to demand. In addition, some or all of the steps in each flowchart may include multiple sub-steps or multiple stages based on actual implementation scenarios. Some or all of these sub-steps or stages may be executed at the same time, and each sub-step or stage in these sub-steps or stages may also be executed at different times respectively. In different scenarios of execution time, the execution order of these sub-steps or stages may be flexibly configured according to demand, and the embodiment of the present application does not limit this.

[0068] The above is only an optional implementation method for some implementation scenarios of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the technical concept of the solution of the present application, other similar implementation methods based on the technical ideas of the present application are also within the protection scope of the embodiments of the present application.

Claims

1. An undervoltage protection circuit, characterized in that: include: A voltage division sampling unit, a reference voltage device, a bias current providing unit and a switch unit; The voltage-dividing sampling unit comprises: a first resistor and a second resistor connected in series; The input end of the voltage division sampling unit is connected to the voltage detection node of the main circuit, and is used to obtain the input voltage, and output the input voltage to the reference voltage device after voltage division; The output end of the reference voltage device is connected to the input end of the switch unit; Wherein, when the first voltage input to the reference voltage device is not greater than the second voltage of the reference voltage device, the reference voltage device is in a non-conducting state, and the bias current providing unit obtains current from the power supply node of the main circuit and inputs the bias current to the switch unit; The output end of the switch unit is connected to the control node of the main circuit, and after acquiring the bias current, outputs an undervoltage protection signal of the main circuit, wherein the undervoltage protection signal is used to control the main circuit to stop working.

2. The undervoltage protection circuit according to claim 1, characterized in that: The voltage division sampling unit further includes: a filter capacitor; The filter capacitor is connected in parallel to the input end and the output end of the first resistor or the second resistor, and is used to filter the output voltage of the voltage-dividing sampling unit.

3. The undervoltage protection circuit according to claim 1, characterized in that: The reference voltage device includes at least one of the following: Reference voltage comparator, Zener diode.

4. The undervoltage protection circuit according to claim 1, characterized in that: The switch unit includes at least one of the following: Voltage controlled devices, current controlled devices.

5. The undervoltage protection circuit according to claim 4, characterized in that: In the case where the switch unit is a voltage-controlled device, the bias current providing unit includes a third resistor and a diode; the third resistor and the diode are connected in series and connected to the base of the voltage-controlled device; The third resistor provides a bias current to the voltage-controlled device through the diode, so that the voltage-controlled device is in a conducting state.

6. The undervoltage protection circuit according to claim 4, characterized in that: In the case where the switch unit is a current-controlled device, the input undervoltage protection circuit further includes: a fourth resistor; an input end of the fourth resistor is connected to the power supply node of the main circuit, and an output end is connected to the collector of the current-controlled device; The fourth resistor provides a bias current for the current-controlled device, so that the current-controlled device is in a non-conducting state.

7. An undervoltage protection method, applied to the undervoltage protection circuit according to any one of claims 1 to 6, characterized in that: The method comprises: When it is detected that the first voltage output by the voltage-dividing sampling unit is not greater than the second voltage of the reference voltage device, the reference voltage device is switched from a conducting state to a non-conducting state; The switch unit obtains the bias current through the bias current providing unit, and outputs an undervoltage protection signal of the main circuit, wherein the undervoltage protection signal is used to control the main circuit to stop working.

8. The undervoltage protection method according to claim 7, characterized in that: In the case where the switch unit is a voltage-controlled device, the method further includes: After obtaining the bias current through the bias current providing unit, the switch unit switches from a non-conducting state to a conducting state, and controls the main circuit to enter a hiccup protection mode.

9. The undervoltage protection method according to claim 7, characterized in that: In the case where the switch unit is a current-controlled device, the method further includes: After obtaining the bias current through the bias current providing unit, the switch unit switches from a conducting state to a non-conducting state, and stops supplying power to the main circuit.

10. The undervoltage protection method according to any one of claims 7 to 9, characterized in that: The method further comprises: When it is detected that the first voltage output by the voltage-dividing sampling unit is greater than the second voltage of the reference voltage device, the reference voltage device is switched from a non-conducting state to a conducting state; After the reference voltage device is turned on, the potential of the input terminal of the switch unit is reduced, so that the switch unit is switched from a conducting state to a non-conducting state; After the switch unit is switched to the non-conducting state, the potential of the control node of the main circuit returns to normal, and the main circuit returns to the working state.

11. The undervoltage protection method according to any one of claims 7 to 10, characterized in that: The method further comprises: When it is detected that the first voltage output by the voltage-dividing sampling unit is greater than the second voltage of the reference voltage device, the reference voltage device is switched from a non-conducting state to a conducting state; After the reference voltage device is turned on, the potential of the input terminal of the switch unit is reduced, so that the switch unit is switched from a non-conducting state to a conducting state; After the switch unit is switched to the on state, the main circuit starts to be supplied with power.

12. An undervoltage protection device, characterized in that: include: A first processing module, configured to switch the reference voltage device from a conducting state to a non-conducting state when it is detected that the first voltage output by the voltage-dividing sampling unit is not greater than the second voltage of the reference voltage device; The second processing module is used for the switch unit to obtain the bias current through the bias current providing unit, and output the undervoltage protection signal of the main circuit, wherein the undervoltage protection signal is used to control the main circuit to stop working.

13. An electronic device, characterized in that: The method comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the method according to any one of claims 7 to 11 is implemented when the processor executes the program.

14. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 7 to 11 is implemented.

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