Load protection circuit and electronic device

Abstract

The embodiment of the application discloses a load protection circuit and electronic equipment. The load protection circuit comprises a first charging module, a second charging module, a first switch module and a second switch module. Through the cooperation between the first charging module and the second charging module, the difference of the charging conduction time sequence is utilized, when the load is normal, the first switch module is preferentially turned on so that the power supply voltage is transmitted to the load through the first switch module; when the load is short-circuited, the second switch module is turned on first and then the first switch module is turned off in a linkage mode, so that the power supply circuit of the load can be quickly cut off; after the short-circuit fault of the load is removed, the second switch module is still kept on to maintain the turn-off of the first switch module, so that the self-locking turn-off closed loop of the first switch module is formed, the automatic reset of the load after the short-circuit fault of the load is removed is avoided, and the load is prevented from being damaged again, so that the safety and reliability of the load are improved.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, specifically to a load protection circuit and electronic device. Background Technology

[0002] In the power supply systems of electronic products, short-circuit protection or overcurrent protection functions are usually set up to deal with short-circuit or overcurrent faults on the load side. When a short circuit or overcurrent occurs in the load, the power supply system automatically cuts off the power supply circuit to the load. However, when the short circuit or overcurrent fault is eliminated, the power supply system automatically restores power supply, which can easily cause secondary damage to the load and affect the stability of the equipment. Summary of the Invention

[0003] To address the aforementioned technical problems, embodiments of this application provide a load protection circuit and electronic device, which improves upon the situation where, in related technologies, automatically restoring power to the load after a load fault is cleared can easily cause secondary damage to the load.

[0004] In a first aspect, embodiments of this application provide a load protection circuit, including a first charging module, a second charging module, a first switching module, and a second switching module; both the first charging module and the second charging module are charged based on an input supply voltage; the first switching module and the second switching module are interconnected and respectively connected to the first charging module and the second charging module; the first charging module and the second charging module provide turn-on voltages to the first switching module and the second switching module, respectively, and the first charging module is configured to charge to the turn-on voltage before the second charging module; when the supply voltage is applied, the first charging module is used to turn on the first switching module first over the second charging module. The first switching module outputs the load voltage; the second switching module is used to turn off the first switching module based on its conduction and to cut off the charging process of the second charging module to maintain the conduction of the first switching module; the second charging module is used to resume the charging process when the voltage at the output terminal of the first switching module drops due to a load short circuit, and the second switching module is used to turn on based on the charging voltage of the second charging module after the charging is resumed, while the first switching module is used to turn off based on the conduction of the second switching module; when the load is de-short-circuited, the second charging module is used to maintain the charging process to keep the second switching module on, so that the first switching module remains in a locked off state.

[0005] Optionally, the first charging module includes a first energy storage unit and a first impedance unit; a first end of the first energy storage unit is connected to the first switching module, a second end of the first energy storage unit is connected to the first end of the first impedance unit, and the second end of the first impedance unit is grounded; the control terminal of the first switching module is connected in parallel to the two ends of the first energy storage unit, and the first energy storage unit is charged based on the supply voltage to provide a conduction voltage for the first switching module.

[0006] Optionally, the second charging module includes a second energy storage unit, a second impedance unit, a third impedance unit, and a sampling resistor; the first end of the second energy storage unit is connected to the power supply module, the second end of the second energy storage unit is connected to the first end of the second impedance unit, the second end of the second impedance unit is connected to the first end of the third impedance unit, the second end of the third impedance unit is grounded, the sampling resistor is used to connect the output terminal of the first switching module and the load, the second end of the second impedance unit and the first end of the third impedance unit are also connected to the connection point of the sampling resistor and the first switching module, and the two ends of the second energy storage unit are also connected in parallel to the control terminal of the second switching module to provide a conduction voltage for the second switching module; at the instant the power supply voltage is applied, the second energy storage unit... The first charging circuit of the second charging module is formed by the energy storage unit, the second impedance unit, and the third impedance unit. The first switching module is used to output a supply voltage when it is turned on so that the voltages across the second energy storage unit are equal, thereby cutting off the charging process of the second energy storage unit in the first charging circuit. The resistance of the third impedance unit is greater than the resistance of the sampling resistor. When the load is short-circuited, the second energy storage unit, the second impedance unit, and the sampling resistor form a second charging circuit that is superior to the charging of the first charging circuit. The second charging circuit is used to restore the charging process of the second charging module when the load is short-circuited, thereby turning on the second switching module. When the load is de-short-circuited, the second charging circuit is disconnected and the first charging circuit is used to maintain the charging process of the second charging module.

[0007] Optionally, the first switching module includes a first switching transistor; the base and emitter of the first switching transistor are both connected to the first charging module, and the collector of the first switching transistor is used to connect to the load; the collector of the first switching transistor is also connected to the control terminal of the second switching module, and the base and emitter of the first switching transistor are connected to the output terminal of the second switching module.

[0008] Optionally, the second switching module includes a second switching transistor; the base and emitter of the second switching transistor are both connected to the second charging module, and the collector of the second switching transistor is used to connect to the first switching module.

[0009] Optionally, the load protection circuit further includes a power supply activation module, which includes an input switch, a voltage regulator activation module, and a third switch module. A power supply voltage is applied to the first terminal of the input switch, and the second terminal of the input switch is connected to the voltage regulator activation module and the third switch module respectively. The voltage regulator activation module is connected between the source and gate of the third switch module, and the drain of the third switch module is connected to the first charging module, the second charging module, the first switch module, and the second switch module respectively. The voltage regulator activation module is used to drive the third switch module to activate when the input switch is activated, so that the power supply voltage is transmitted to the first charging module, the second charging module, the first switch module, and the second switch module respectively through the drain of the third switch module.

[0010] Optionally, the voltage regulation and conduction module includes a fourth impedance unit, a fifth impedance unit, a sixth impedance unit, a seventh impedance unit, and a three-terminal regulator. The first terminal of the fourth impedance unit, the first terminal of the sixth impedance unit, and the source of the third switching module are respectively connected to the second terminal of the input switch. The second terminal of the fourth impedance unit and the first terminal of the fifth impedance unit are respectively connected to the reference terminal of the three-terminal regulator. The second terminal of the fifth impedance unit and the anode of the three-terminal regulator are respectively grounded. The second terminal of the sixth impedance unit and the first terminal of the seventh impedance unit are respectively connected to the cathode of the three-terminal regulator. The second terminal of the seventh impedance unit is electrically connected to the gate of the third switching module.

[0011] Optionally, the load protection circuit further includes an overcurrent detection module. The input and output terminals of the overcurrent detection module are connected to a sampling resistor and the control terminal of the first switching module, respectively. The sampling resistor is used to sample the current signal at the output terminal of the first switching module that supplies power to the load, and to provide feedback of an overcurrent signal when an overcurrent occurs at the output terminal of the first switching module. The overcurrent detection module is used to control the first switching module to turn off based on the overcurrent signal.

[0012] Optionally, the overcurrent detection module includes a first overcurrent switch module, a unidirectional conduction module, and a second overcurrent switch module; the control terminal and output terminal of the first overcurrent switch module are respectively connected to the sampling resistor and the input terminal of the unidirectional conduction module; the control terminal and output terminal of the second overcurrent switch module are respectively connected to the output terminal of the unidirectional conduction module and the control terminal of the first switch module; the first overcurrent switch module is used to conduct based on the overcurrent signal to output an overcurrent voltage, the unidirectional conduction module is used to conduct unidirectionally based on the overcurrent voltage to output an overcurrent control signal, and the second overcurrent switch module is used to conduct based on the overcurrent control signal to turn off the first switch module.

[0013] In a second aspect, embodiments of this application provide an electronic device including the load protection circuit described above.

[0014] The beneficial effects of the load protection circuit provided in this application embodiment are as follows: This application embodiment utilizes the coordinated operation between the first charging module and the second charging module, taking advantage of the difference in charging turn-on timing. When the load is normal, the first switching module is preferentially turned on so that the supply voltage can be transmitted to the load through the first switching module. When the load is short-circuited, a linkage method is used to first turn on the second switching module and then turn off the first switching module, thereby quickly cutting off the power supply circuit to the load. After the load short-circuit fault is cleared, the second switching module remains on to maintain the first switching module's off state, thus forming a self-locking turn-off closed loop for the first switching module. This prevents the load from automatically resetting and energizing after the load short-circuit fault is cleared, which could cause secondary damage to the load, thereby improving the safety and reliability of the load. Furthermore, in constructing the self-locking turn-off closed loop of the first switching module, this application embodiment does not use any triggers, latches, or chips involved in the self-locking process. It relies only on a few discrete components and uses a hardware self-locking method to construct the self-locking turn-off closed loop of the first switching module. The hardware self-locking method has a high speed and can quickly protect the load. Attached Figure Description

[0015] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0016] Figure 1 A schematic diagram of the circuit structure of a load protection circuit provided in an embodiment of this application; Figure 2 A schematic diagram of the circuit structure of a load protection circuit provided in another embodiment of this application; Figure 3 A schematic diagram of the circuit structure of a load protection circuit provided in another embodiment of this application; Figure 4 A schematic diagram of the specific circuit structure of a load protection circuit provided in an embodiment of this application; Figure 5 A schematic diagram of the circuit structure of a load protection circuit provided in another embodiment of this application; Figure 6 A schematic diagram of the circuit structure of a load protection circuit provided in another embodiment of this application; Figure 7 A schematic diagram of the circuit structure of a load protection circuit provided in another embodiment of this application; Figure 8 A schematic diagram of the circuit structure of a load protection circuit provided in another embodiment of this application; Figure 9A schematic diagram of the circuit structure of a load protection circuit provided in another embodiment of this application; Figure 10 This is a schematic diagram of the specific circuit structure of a load protection circuit provided in another embodiment of this application. Detailed Implementation

[0017] To facilitate understanding of this application, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as being "electrically connected" to another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "upper," "lower," "inner," "outer," "bottom," etc., used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0018] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items. Furthermore, technical features involved in the different embodiments of this application described below may be combined with each other as long as they do not conflict with each other.

[0019] To address short-circuit or overcurrent faults on the load side, the power supply system primarily employs a design logic of fault triggering → fault elimination → automatic power restoration. When an overcurrent or short circuit occurs in the load, the power supply system disconnects the load's power supply circuit to protect itself. Once the load fault is cleared, the power supply system automatically restores power to the load. However, if the load itself has a persistent fault, such as component damage or an internal short circuit, the power supply system may repeatedly switch between power outages and restorations. This can easily cause multiple impacts on the load, leading to secondary damage and exacerbating the load's fault condition.

[0020] Therefore, this application provides a load protection circuit that provides dual protection against short circuits and overcurrent in low-current output scenarios, and also features a fault self-locking function. When a short circuit or overcurrent occurs in the load, the load protection circuit automatically disconnects the power supply circuit to the load. Once the load protection circuit enters the self-locking state, even if the load fault disappears, the load protection circuit will not automatically reconnect the power supply circuit to the load. This avoids repeated power-on of the load and prevents secondary damage, ensuring stable operation of the electronic equipment.

[0021] The following embodiments of this application provide a load protection circuit, which is applied in various electronic devices. Please refer to... Figure 1 The load protection circuit 100 includes a first charging module 200, a second charging module 300, a first switch module 400, and a second switch module 500.

[0022] Both the first charging module 200 and the second charging module 300 charge based on the input supply voltage. The supply voltage is the voltage that drives the load 600 to operate. The supply voltage is either the DC voltage converted from the AC mains voltage by the electronic device, or the DC voltage obtained after the electronic device performs a boost or buck operation on the internal DC voltage.

[0023] The circuit topology of the first charging module 200 and the second charging module 300 can be configured into a suitable charging topology with charging function according to the purpose of the embodiments of this application. For example, the first charging module 200 or the second charging module 300 can be a charging topology composed of an energy storage unit and a resistor network. Even more exemplaryly, the first charging module 200 or the second charging module 300 can be a charging topology composed only of an energy storage unit.

[0024] The first switch module 400 and the second switch module 500 are interconnected and respectively connected to the first charging module 200 and the second charging module 300. That is, the first switch module 400 is connected to the second switch module 500, the first charging module 200 and the second charging module 300 respectively, and the second switch module 500 is connected to the first switch module 400, the first charging module 200 and the second charging module 300 respectively.

[0025] The circuit topology of the first switch module 400 and the second switch module 500 can be configured into a suitable switch topology with switching function according to the purpose of the embodiments of this application. For example, the first switch module 400 or the second switch module 500 can be a switch topology composed of a single switching transistor. This switching transistor can be a transistor, MOSFET, IGBT, thyristor, etc. As another example, the first switch module 400 or the second switch module 500 can be a switch topology composed of one or more switching transistors and impedance units or capacitor units.

[0026] The first charging module 200 and the second charging module 300 provide the first switch module 400 and the second switch module 500 with the turn-on voltage, respectively, and the first charging module 200 is configured to charge to the turn-on voltage before the second charging module 300.

[0027] The turn-on voltage refers to the voltage that can drive the first switching module 400 into the turn-on state. The magnitude of the turn-on voltage is related to the switching topology of the first switching module 400 and the type of switching transistor. For example, the first switching module 400 is a silicon PNP transistor, and the turn-on voltage is 0.6V or 0.7V, etc.

[0028] It is understandable that for a charging module, the smaller the time constant of the charging module, the faster the charging voltage rises; conversely, the larger the time constant of the charging module, the slower the charging voltage rises.

[0029] The time constant of the first charging module 200 is less than that of the second charging module 300. That is, the charging voltage of the first charging module 200 rises faster than that of the second charging module 300. Therefore, during the charging process, the first charging module 200 charges to the turn-on voltage before the second charging module 300. In other words, the charging voltage of the first charging module 200 reaches the turn-on voltage earlier, which causes the first charging module 200 to trigger the first switching module 400 to enter the turn-on state first.

[0030] When the power supply voltage is connected, the first charging module 200 is used to prioritize turning on the first switching module 400 over the second charging module 300, so that the first switching module 400 outputs the power supply voltage of the load 600.

[0031] The second switch module 500 is used to turn off the first switch module 400 based on its conduction, and to cut off the charging process of the second charging module 300 in order to maintain the conduction of the first switch module 400.

[0032] When the first switch module 400 enters the ON state, the supply voltage is fed back from the first switch module 400 to the second switch module 500 and the second charging module 300, causing the second switch module 500 to enter the OFF state and the second charging module 300 to fail to meet the charging conditions and enter a charging failure state. When the second switch module 500 enters the OFF state, the OFF second switch module 500 controls the first switch module 400 to maintain the ON conditions, thereby keeping the first switch module 400 ON. At this time, the supply voltage is normally transmitted to the load 600 through the ON first switch module 400 to drive the load 600 to work normally.

[0033] In this embodiment of the application, when the load 600 is in a normal state, after the power supply voltage is supplied, the first charging module 200 preferentially turns on the first switching module 400 so as to control the second switching module 500 to enter the off state, and the second charging module 300 cannot meet the charging conditions and enters the charging failure state. In this way, the off second switching module 500 strengthens the conduction of the first switching module 400 in a self-locking manner, so that the power supply voltage can be continuously transmitted to the load 600 through the conducting first switching module 400, thereby ensuring that the load 600 can work normally, reliably and stably.

[0034] The second charging module 300 is used to resume the charging process in the event of a voltage drop at the output of the first switching module 400 caused by a short circuit in the load 600. The second switching module 500 is used to turn on the charging voltage of the second charging module based on the resumed charging. The first switching module 400 is used to turn off the second switching module 500 based on the turned-on state.

[0035] When the load 600 is short-circuited, the output of the first switching module 400 is pulled low, and the voltage at the output of the first switching module 400 switches from the previous supply voltage to zero voltage. Therefore, the second charging module 300 meets the charging conditions and enters the charging state, resuming the charging process. The charging voltage of the second charging module 300 then rises. When the charging voltage of the second charging module 300 reaches the conduction voltage of the second switching module 500, it triggers the second switching module 500 to enter the conduction state. When the second switching module 500 enters the conduction state, it transmits the supply voltage to the control terminal of the first switching module 400. The control terminal of the first switching module 400 is supplied with the supply voltage, causing the first switching module 400 to enter the off state instead of meeting the conduction conditions. This disconnects the supply voltage transmission circuit to the load 600, preventing short-circuit current from damaging the load 600, thus achieving the short-circuit protection function.

[0036] When the load 600 is de-short-circuited, the second charging module 300 is used to maintain the charging process to keep the second switch module 500 on, so that the first switch module 400 remains in a locked off state.

[0037] Understandably, although the short-circuit fault of load 600 is cleared, the second charging module 300 continues the charging process, and the charging voltage of the second charging module 300 can still trigger the second switching module 500 to enter the conducting state. In the conducting state, the second switching module 500 can still control the first switching module 400 to be in the off state, and the power supply circuit for transmitting power to load 600 remains disconnected. Therefore, even if the short-circuit fault of load 600 is cleared, the load protection circuit 100 will not supply power to load 600, thus preventing secondary damage to load 600.

[0038] This embodiment utilizes the coordinated operation between the first charging module 200 and the second charging module 300, taking advantage of the difference in charging turn-on timing. When the load 600 is normal, the first switching module 400 is turned on first so that the power supply voltage can be transmitted to the load 600 through the first switching module 400. When the load 600 is short-circuited, the second switching module 500 is turned on first in a linkage manner, and then the first switching module 400 is turned off, thereby quickly cutting off the power supply circuit of the load 600. After the short-circuit fault of the load 600 is cleared, the second switching module 500 is kept on to maintain the first switching module 400 being off. This forms a self-locking turn-off closed loop of the first switching module 400, avoiding automatic reset and power-on after the short-circuit fault of the load 600 is cleared, which could cause secondary damage to the load, thereby improving the safety and reliability of the load 600.

[0039] In addition, in constructing the self-locking shutdown closed loop of the first switch module 400 in this embodiment, no triggers, latches or chips are used to participate in the self-locking process. Only a few discrete devices are used to construct the self-locking shutdown closed loop of the first switch module 400 using a hardware self-locking method. The hardware self-locking method has a high speed and can quickly protect the load 600.

[0040] Please see Figure 2 The load protection circuit 100 also includes a power supply activation module 700, which is connected to the first charging module 200, the second charging module 300, the first switch module 400, and the second switch module 500. The power supply activation module 700 is used to control the input of the power supply voltage.

[0041] When the power supply module 700 is in the ON state, the power supply voltage is transmitted through the power supply module 700 to the first charging module 200, the second charging module 300, the first switch module 400, and the second switch module 500, respectively. When the power supply module 700 is in the OFF state, the power supply module 700 disconnects the circuit for transmitting the power supply voltage to the first charging module 200, the second charging module 300, the first switch module 400, and the second switch module 500.

[0042] Please see Figure 3The first charging module 200 includes a first energy storage unit 21 and a first impedance unit 22. A first end of the first energy storage unit 21 is connected to a first switching module 400, and a second end of the first energy storage unit 21 is connected to a first end of the first impedance unit 22. The second end of the first impedance unit 22 is grounded. The control terminal of the first switching module 400 is connected in parallel across the two ends of the first energy storage unit 21. The first energy storage unit 21 is charged based on the supply voltage to provide a turn-on voltage for the first switching module 400. The first energy storage unit 21 can be a single capacitor or a circuit with energy storage function composed of multiple capacitors. The first impedance unit 22 can be a single resistor or a resistor network.

[0043] In this embodiment, the first charging module 200 is configured as a first energy storage unit 21 and a first impedance unit 22. Through the coordinated operation between the first energy storage unit 21 and the first impedance unit 22, the corresponding actions can be performed according to a predetermined action sequence, so as to ensure that the first switching module 400 operates reliably.

[0044] Please see Figure 4 In some embodiments, the first energy storage unit 21 is a first capacitor C1, and the first impedance unit 22 is a first resistor R1. Under normal load conditions, when the supply voltage VIN is connected, the supply voltage charges the first capacitor C1 through the first resistor R1; that is, the first capacitor C1 is charged based on the supply voltage. When the voltage across the first capacitor C1 (i.e., the charging voltage) is greater than or equal to the conduction voltage, the first switch module 400 enters the conduction state. When the first switch module 400 enters the conduction state, it outputs the operating voltage for the load 600.

[0045] Under the condition of a short circuit in load 600, the second charging module 300 resumes the charging process. The charging voltage of the second charging module 300 can trigger the second switching module 500 to conduct. The second switching module 500 transmits the supply voltage to the second terminal of the first capacitor C1 and the control terminal of the first switching module 400. The first switching module 400 remains in the off state, keeping the power supply circuit for transmitting the supply voltage to load 600 disconnected.

[0046] When the load 600 is de-short-circuited, the second charging module 300 is used to maintain the charging process to keep the second switch module 500 on, so that the first switch module 400 remains in a locked off state.

[0047] Please see Figure 5 The second charging module 300 includes a second energy storage unit 31, a second impedance unit 32, a third impedance unit 33, and a sampling resistor Rm.

[0048] The first end of the second energy storage unit 31 is connected to the power supply module 700. The second end of the second energy storage unit 31 is connected to the first end of the second impedance unit 32. The second end of the second impedance unit 32 is connected to the first end of the third impedance unit 33. The second end of the third impedance unit 33 is grounded. The sampling resistor Rm is used to connect the output terminal of the first switch module 400 and the load 600. The second end of the second impedance unit 32 and the first end of the third impedance unit 33 are also connected to the connection point of the sampling resistor Rm and the first switch module 400. The two ends of the second energy storage unit 31 are also connected in parallel to the control terminal of the second switch module 500 to provide the second switch module 500 with the turn-on voltage.

[0049] At the instant the power supply voltage is applied, the second energy storage unit 31, the second impedance unit 32, and the third impedance unit 33 form the first charging circuit of the second charging module 300. The first switching module 400 is used to output the power supply voltage when it is turned on so that the voltages across the second energy storage unit 31 are equal, thereby cutting off the charging process of the second energy storage unit 31 in the first charging circuit. The resistance value of the third impedance unit 33 is greater than the resistance value of the sampling resistor Rm.

[0050] For example, when the power supply voltage is applied and the first switch module 400 is in the ON state, the power supply voltage is fed back to the second terminal of the second energy storage unit 31 and the control terminal of the second switch module 500 through the first switch module 400, making the voltage at the first terminal and the voltage at the second terminal of the second energy storage unit 31 approximately equal or equal, thus stopping the charging of the second energy storage unit 31, i.e., the charging process of the second energy storage unit 31 in the first charging circuit is cut off. At the same time, the second switch module 500 remains in the OFF state under the action of the feedback power supply voltage.

[0051] When the load 600 is short-circuited, the second energy storage unit 31, the second impedance unit 32, and the sampling resistor Rm form a second charging circuit that is superior to the charging circuit of the first charging circuit. The second charging circuit is used to restore the charging process of the second charging module 300 when the load 600 is short-circuited, so as to turn on the second switching module 500. When the load is de-short-circuited, the second charging circuit is disconnected, and the first charging circuit is used to maintain the charging process of the second charging module 300.

[0052] For example, when the load 600 is short-circuited, the voltage at the output terminal of the first switching module 400 is pulled to ground. Since the resistance of the third impedance unit 33 is greater than the resistance of the sampling resistor Rm, the charging current flows through the second energy storage unit 31, the second impedance unit 32, and the sampling resistor Rm, respectively. That is, the second energy storage unit 31, the second impedance unit 32, and the sampling resistor Rm form the second charging circuit of the second charging module 300. The voltage across the second energy storage unit 31 gradually reaches the turn-on voltage during the charging process. This turn-on voltage can drive the second switching module 500 to switch from the off state to the on state. When the second switching module 500 enters the on state, the supply voltage is transmitted to the control terminal of the first switching module 400 through the second switching module 500, causing the first switching module 400 to no longer meet the turn-on condition and enter the off state, thereby disconnecting the power supply circuit of the load 600.

[0053] When the load 600 is de-circuited, the second charging circuit is disconnected and the first charging circuit is re-formed. Therefore, the second energy storage unit 31 remains in a charging state. The conduction voltage provided by the second energy storage unit 31 can still drive the second switch module 500 to switch from the off state to the on state. The on-state second switch module 500 can still control the first switch module 400 to remain in the off state.

[0054] According to the predetermined action sequence, the second charging module 300 can be flexibly configured as a first charging circuit or a second charging circuit under different load conditions and according to the external environment. This allows the second charging module 300 to reliably control the second switching module 500 to perform corresponding actions based on the load's operating conditions. For example, when the load is normal, the second switching module 500 is controlled to turn off so that the first switching module 400 remains on. When the load is short-circuited or the short circuit is cleared, the second switching module 500 is controlled to turn on so that the first switching module 400 is turned off. Therefore, the load protection circuit 100 can adapt to the load's operating conditions and provide the best working environment for the load.

[0055] Please combine Figure 4In some embodiments, the second energy storage unit 31 is a second capacitor C2, the second impedance unit 32 is a second resistor R2, and the third impedance unit 33 is a third resistor R3. When the power supply voltage is applied and the first switching module 400 is in the on state, the power supply voltage is fed back to the second terminal of the second capacitor C2 and the control terminal of the second switching module 500 through the first switching module 400, making the voltage at the first terminal and the voltage at the second terminal of the second capacitor C2 approximately equal or equal, and the second capacitor C2 stops charging. When the load 600 is short-circuited, the voltage at the output terminal of the first switching module 400 is pulled to ground. Since the resistance of the third resistor R3 is greater than the resistance of the sampling resistor Rm, the second capacitor C2, the second resistor R2, and the sampling resistor Rm form a second charging circuit. The voltage across the second capacitor C2 drives the second switching module 500 to switch from the off state to the on state. When the load 600 is de-circuited, the second charging circuit is disconnected. The second capacitor C2, the second resistor R2 and the third resistor R3 constitute the first charging circuit. Therefore, the second capacitor C2 remains in the charging state, and the conduction voltage provided by the second capacitor C2 can still drive the second switch module 500 to switch from the off state to the on state.

[0056] Please continue reading. Figure 4 The first switching module 400 includes a first switching transistor Q1, which is a PNP transistor. Both the base and emitter of the first switching transistor Q1 are connected to the first charging module 200. For example... Figure 4 As shown, the base of the first switching transistor Q1 is connected to the first end of the first resistor R1, and the emitter of the first switching transistor Q1 is connected to the first end of the first capacitor C1.

[0057] The collector of the first switching transistor Q1 is used to connect to the load 600. The collector of the first switching transistor Q1 is also connected to the control terminal of the second switching module 500, and the base and emitter of the first switching transistor Q1 are connected to the output terminal of the second switching module 500. For example... Figure 4 As shown, the collector of the first switch Q1 is connected to the first end of the sampling resistor Rm, the second end of the second resistor R2, and the first end of the third resistor R3, respectively.

[0058] When the load 600 is normal, the first capacitor C1 triggers the first switch Q1 to conduct first, prior to the second capacitor C2. The supply voltage can be transmitted to the load 600 through the conducting first switch Q1. At the same time, the supply voltage is fed back to the second terminal of the second capacitor C2 and the second switch module 500 through the second resistor R2, causing the second capacitor C2 to stop charging and the second switch module 500 to turn off.

[0059] When the load 600 is short-circuited, the second capacitor C2, the second resistor R2, and the sampling resistor Rm form a second charging circuit. The voltage across the second capacitor C2 drives the second switch module 500 to switch from the off state to the on state. When the second switch module 500 enters the on state, the voltage at the base of the first switch transistor Q1 is close to equal to the supply voltage. At the same time, the voltage at the emitter of the first switch transistor Q1 is equal to the supply voltage. Therefore, the voltage difference between the emitter and base of the first switch transistor Q1 is less than the on-state voltage drop of the first switch transistor Q1. The first switch transistor Q1 enters the off state, and the supply voltage cannot be transmitted to the load 600 through the first switch transistor Q1.

[0060] When the load 600 is de-short-circuited, the second capacitor C2, the second resistor R2, and the third resistor R3 form the first charging circuit. The voltage across the second capacitor C2 can still drive the second switching module 500 to remain on. The first switching transistor Q1 remains off, and the supply voltage still cannot be transmitted to the load 600 through the first switching transistor Q1.

[0061] In this embodiment, the first switch module 400 is configured as the first switch transistor Q1. Multiple functions, including power supply output control and fault self-locking, are realized through a simple switching device, which effectively improves the overall circuit's operational safety and stability.

[0062] Please continue reading. Figure 4 The second switching module 500 includes a second switching transistor Q2, which is a PNP transistor. The base and emitter of the second switching transistor Q2 are both connected to the second charging module 300, and the collector of the second switching transistor Q2 is used to connect to the first switching module 400. Figure 4 As shown, the emitter of the second switch Q2 is connected to the first terminal of the second capacitor C2, the base of the second switch Q2 is connected to the second terminal of the second capacitor C2, and the collector of the second switch Q2 is connected to the base of the first switch Q1 and the first terminal of the first resistor R1, respectively.

[0063] This application's embodiments are combined with Figure 4 The working principle of load 600 under normal, short-circuit, and short-circuit clearing conditions is explained in detail below: ① When the load 600 is normal, the power supply module 700 is in the conducting state. The power supply voltage charges the first capacitor C1 through the first charging circuit formed by the first capacitor C1, the first resistor R1, the third resistor R3, and the ground terminal. The power supply voltage also charges the second capacitor C2 through the charging circuit formed by the second capacitor C2, the second resistor R2, the third resistor R3, and the ground terminal. The voltage at the first terminal of the first capacitor C1 and the first terminal of the second capacitor C2 are close to the power supply voltage. Considering that the voltage difference between the two terminals of the first capacitor C1 and the second capacitor C2 cannot change abruptly, the voltage at the second terminal of the first capacitor C1 and the second terminal of the second capacitor C2 is momentarily raised to a value close to the power supply voltage. As the charging process continues, the voltage at the second terminal of the first capacitor C1 and the second terminal of the second capacitor C2 gradually decrease.

[0064] The time constant corresponding to the first capacitor C1 is less than the time constant corresponding to the second capacitor C2. Therefore, the voltage at the first terminal of the first capacitor C1 and the voltage at the first terminal of the second capacitor C2 remain close to the target voltage. The voltage at the second terminal of the first capacitor C1 decreases rapidly compared to the voltage at the second terminal of the second capacitor C2, causing the voltage across the first capacitor C1 to rapidly exceed the on-state voltage drop of the first switch Q1. For example, the voltage across the first capacitor C1 rapidly exceeds 0.7V. Therefore, the first switch Q1 enters the on state, while the second switch Q2 is in the off state.

[0065] When the first switch Q1 is turned on, the supply voltage output from the collector of the first switch Q1 is fed back to the second terminal of the second capacitor C2 and the base of the second switch Q2 through the second resistor R2. The second capacitor C2 stops charging, and the second switch Q2 remains off. At this time, the supply voltage is transmitted to the load through the first switch Q1.

[0066] ② When load 600 is short-circuited, for example, when the load switch key is closed, load 600 is short-circuited. The collector voltage of the first switch Q1 is pulled low, and the voltage at the second terminal of the second capacitor C2 is pulled low. Since the resistance of the third resistor R3 is greater than the resistance of the sampling resistor Rm, the second capacitor C2, the second resistor R2, the sampling resistor Rm, the load switch key, and the ground terminal form a second charging circuit. The supply voltage charges the second capacitor C2 through the second charging circuit, causing the voltage across the second capacitor C2 to gradually increase. When the voltage across the second capacitor C2 is greater than the on-state voltage drop of the second switch Q2, the second switch Q2 enters the conducting state.

[0067] When the second switch Q2 is turned on, the supply voltage is transmitted to the base of the first switch Q1 through the second switch Q2. The voltage at the base of the first switch Q1 is almost equal to the voltage at its emitter, which is equivalent to short-circuiting the base and emitter of the first switch Q1, causing the first switch Q1 to turn off. The power supply circuit of the load 600 is disconnected. Therefore, the supply voltage cannot be transmitted to the load 600 through the first switch Q1, thereby avoiding damage to the load 600 and the load protection circuit 100 by the short-circuit current.

[0068] ③ When the load 600 is uncircuited, since the resistance of the third resistor R3 is greater than the resistance of the sampling resistor Rm, the charging circuit of the second capacitor C2 switches from the second charging circuit to the first charging circuit. The power supply voltage charges the second capacitor C2 through the first charging circuit. The voltage across the second capacitor C2 can still drive the second switch Q2 to remain on, so that the first switch Q1 remains off. The power supply voltage still cannot be transmitted to the load 600 through the first switch Q1, thereby avoiding the load from being automatically reset and powered on after the short circuit fault of the load 600 is cleared, which would cause secondary damage to the load. This improves the safety and reliability of the load 600.

[0069] Please see Figure 6 The power supply module 700 includes an input switch 71, a voltage regulator module 72, and a third switch module 73.

[0070] The first terminal of the input switch 71 is supplied with a power supply voltage, and the second terminal of the input switch 71 is connected to the voltage regulator module 72 and the third switch module 73, respectively. The input switch 71 can be an electronic switch, a physical switch, or a relay.

[0071] The voltage regulator module 72 is connected between the source and gate of the third switching module 73. The drain of the third switching module 73 is connected to the first charging module 200, the second charging module 300, the first switching module 400, and the second switching module 500, respectively. The voltage regulator module 72 is used to drive the third switching module 73 to conduct when the input switch 71 is turned on, so that the supply voltage is transmitted to the first charging module 200, the second charging module 300, the first switching module 400, and the second switching module 500 through the drain of the third switching module 73, respectively.

[0072] This application embodiment uses a power supply module 700 composed of an input switch 71, a voltage regulation module 72, and a third switch module 73 to realize the controllable power-on and voltage regulation start-up functions of the load protection circuit 100, which is beneficial to improving the safety, stability, and controllability of the load protection circuit 100.

[0073] Please see Figure 7The voltage regulation and conduction module 72 includes a fourth impedance unit 721, a fifth impedance unit 722, a sixth impedance unit 723, a seventh impedance unit 724, and a three-terminal regulator 725. The first terminal of the fourth impedance unit 721, the first terminal of the sixth impedance unit 723, and the source of the third switching module 73 are respectively connected to the second terminal of the input switch 71. The second terminal of the fourth impedance unit 721 and the first terminal of the fifth impedance unit 722 are respectively connected to the reference terminal of the three-terminal regulator 725. The second terminal of the fifth impedance unit 722 and the anode of the three-terminal regulator 725 are respectively grounded. The second terminal of the sixth impedance unit 723 and the first terminal of the seventh impedance unit 724 are respectively connected to the cathode of the three-terminal regulator 725. The second terminal of the seventh impedance unit 724 is electrically connected to the gate of the third switching module 73.

[0074] Please combine Figure 4 In some embodiments, the fourth impedance unit 721 is the fourth resistor R4, the fifth impedance unit 722 is the fifth resistor R5, the sixth impedance unit 723 is the sixth resistor R6, the seventh impedance unit 724 is the seventh resistor R7, and the third switch module 73 is the third switch transistor Q3. The third switch transistor Q3 is a PMOS transistor.

[0075] When input switch 71 is not pressed, the power supply voltage is not connected, the three-terminal regulator 725 is in the off state, the third switch Q3 is not in the conduction condition and is also in the off state, so the power supply voltage cannot be transmitted to the next stage circuit through the third switch Q3. The preset voltage regulation threshold is... ,in, To preset the voltage regulation threshold, The reference voltage for the three-terminal regulator 725 is, for example, 2.5V.

[0076] When the input switch 71 is pressed, but the supply voltage is less than the preset voltage regulation threshold, the three-terminal regulator 725 is in the off state, and the working state of the load protection circuit 100 is the same as described above, which will not be repeated here.

[0077] When the power supply voltage is connected and is greater than or equal to the preset voltage regulation threshold, the three-terminal regulator 725 enters the conducting state, thereby pulling down the gate voltage of the third switch Q3. The source voltage of the third switch Q3 is clamped to the preset voltage regulation threshold. Therefore, when the power supply voltage becomes abnormally large, such as when the power supply voltage is input in the form of a surge voltage, after the power supply voltage is regulated by the voltage regulation module 72, the voltage applied to the source of the third switch Q3 is clamped to the preset voltage regulation threshold, thereby preventing excessively high power supply voltage from being transmitted to the next stage circuit and damaging the devices in the next stage circuit.

[0078] This embodiment of the application achieves voltage regulation of the power supply voltage and voltage regulation of the third switch Q3 through the voltage regulation and conduction module 72. When the power supply voltage is low, the three-terminal regulator 725 controls the third switch Q3 to turn off, preventing the next stage circuit from operating in an undervoltage state. When the power supply voltage abnormally increases, the three-terminal regulator 725 stably controls the third switch Q3 to turn on and clamps the output voltage of the third switch Q3 within a safe threshold range, preventing excessively high power supply voltage from damaging the components of the next stage circuit. This improves the overall circuit safety and operational stability.

[0079] Please see Figure 8 The load protection circuit 100 also includes an overcurrent detection module 800. The input and output terminals of the overcurrent detection module 800 are respectively connected to a sampling resistor Rm and the control terminal of the first switching module 400. The sampling resistor Rm is used to sample the current signal at the output terminal of the first switching module 400 that supplies power to the load 600, and to provide feedback of an overcurrent signal when an overcurrent occurs at the output terminal of the first switching module 400. The overcurrent detection module 800 is used to control the first switching module 400 to turn off based on the overcurrent signal.

[0080] The overcurrent signal is the voltage across the sampling resistor Rm after a large current flows through it. When the load 600 experiences an overcurrent, the current signal flowing through the sampling resistor Rm is large, and the voltage across Rm is also large. The sampling resistor Rm feeds back the overcurrent signal to the overcurrent detection module 800. Based on the overcurrent signal, the overcurrent detection module 800 controls the first switch module 400 to turn off, preventing the supply voltage from being transmitted to the load 600 through the first switch module 400. This removes the overcurrent condition from the load protection circuit 100 and the load 600, thus preventing damage to the components of the load protection circuit 100 or the load 600 due to excessive current and improving the operational safety and reliability of the load protection circuit 100 or the load 600.

[0081] Please see Figure 9 The overcurrent detection module 800 includes a first overcurrent switch module 81, a unidirectional conduction module 82, and a second overcurrent switch module 83. The control terminal and output terminal of the first overcurrent switch module 81 are respectively connected to the sampling resistor Rm and the input terminal of the unidirectional conduction module 82. The control terminal and output terminal of the second overcurrent switch module 83 are respectively connected to the output terminal of the unidirectional conduction module 82 and the control terminal of the first switch module 400.

[0082] The first overcurrent switch module 81 is used to conduct based on an overcurrent signal to output an overcurrent voltage. When an overcurrent signal is applied to the first overcurrent switch module 81, the first overcurrent switch module 81 enters the conducting state. When the first overcurrent switch module 81 is in the conducting state, it transmits the overcurrent voltage to the unidirectional conduction module 82. It is understood that when the sampling resistor Rm does not feed back an overcurrent signal to the first overcurrent switch module 81, the first overcurrent switch module 81 is in the off state.

[0083] The unidirectional conduction module 82 is used to conduct unidirectionally based on the overcurrent voltage to output an overcurrent control signal. When an overcurrent voltage is applied to the unidirectional conduction module 82, the unidirectional conduction module 82 processes the overcurrent voltage to obtain an overcurrent control signal, and transmits the overcurrent control signal to the second overcurrent switch module 83.

[0084] Understandably, the unidirectional conduction module 82 can block the current from the second overcurrent switch module 83 side, preventing the current from the second overcurrent switch module 83 side from flowing back to the load 600 or the first switch module 400 through the conducting first overcurrent switch module 81, thereby isolating the voltage interference from the second overcurrent switch module 83 side.

[0085] The second overcurrent switch module 83 is used to turn on the first switch module 400 based on an overcurrent control signal. When the overcurrent control signal is applied to the second overcurrent switch module 83, the second overcurrent switch module 83 enters the on state. When the second overcurrent switch module 83 enters the on state, the second overcurrent switch module 83 controls the first switch module 400 to enter the off state.

[0086] This application embodiment uses a first overcurrent switch module 81, a one-way conduction module 82, and a second overcurrent switch module 83 to form an overcurrent detection closed-loop structure, which can monitor the overcurrent status of the load protection circuit 100 and the load 600 in real time. When an overcurrent occurs, it can respond to the overcurrent status immediately and quickly shut down the first switch module 400, thereby protecting the load protection circuit 100 and the load 600.

[0087] Please see Figure 10 The first overcurrent switch module 81 includes a fourth switch transistor Q4, which is a PNP transistor. The unidirectional conduction module 82 includes a diode D1 and an eighth resistor R8. The second overcurrent switch module 83 includes a fifth switch transistor Q5, which is an NPN transistor.

[0088] The base of the fourth switch Q4 is connected to the first terminal of the sampling resistor Rm and the load 600. The second terminal of the sampling resistor Rm is connected to the emitter of the fourth switch Q4, the first terminal of the second resistor R2, and the first terminal of the third resistor R3. The collector of the fourth switch Q4 is connected to the anode of the diode D1. The cathode of the diode D1 is connected to the first terminal of the eighth resistor R8. The second terminal of the eighth resistor R8 is connected to the base of the fifth switch Q5. The collector of the fifth switch Q5 is connected to the emitter of the first switch Q1, and the emitter of the fifth switch Q5 is connected to the base of the first switch Q1.

[0089] When an overcurrent occurs in the load, a larger current flows through the first switch Q1 and the sampling resistor Rm, causing a significant voltage difference across the sampling resistor Rm. The resistance value of the sampling resistor Rm is customized by the designer based on engineering experience, and the voltage across Rm closer to the first switch Q1 is greater than the voltage across Rm closer to the load 600Ω. This larger current causes the voltage difference across the sampling resistor Rm to be greater than or equal to the forward voltage drop of the fourth switch Q4. For example, if the forward voltage drop of the fourth switch Q4 is 0.7V, the larger current causing the voltage difference across the sampling resistor Rm to be greater than or equal to 0.7V is equivalent to the sampling resistor Rm feeding back an overcurrent signal to the fourth switch Q4, causing the fourth switch Q4 to turn on.

[0090] When the fourth switch Q4 enters the conducting state, it outputs an overcurrent voltage. After being processed by diode D1 and resistor R8, the overcurrent voltage is applied to the base of the fifth switch Q5 in the form of an overcurrent control signal, causing the fifth switch Q5 to enter the conducting state.

[0091] When the fifth switch Q5 enters the conducting state, the base voltage of the first switch Q1 is raised to the supply voltage. At this time, the emitter voltage of the first switch Q1 is also the supply voltage. Therefore, the voltage difference between the emitter and base of the first switch Q1 is less than the conduction voltage drop, and the conduction condition is not met, so it enters the turn-off state, disconnecting the overcurrent loop of the load protection circuit 100, thereby protecting the load protection circuit 100 and the load 600 from damage by excessive current.

[0092] It is understood that after the short-circuit fault of load 600 is cleared or the overcurrent fault of load 600 is cleared, this embodiment of the application, according to the control method of the above embodiment, still controls the first switch Q1 to be turned off until the input switch 71 is pressed again. Then, this embodiment of the application, according to the control method of the above embodiment, controls the first switch Q1 to be turned on, so that the power supply voltage is transmitted to the load 600 through the turned-on first switch Q1, thereby restoring the normal power supply to the load 600.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this application as described above, which are not provided in detail for the sake of brevity; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A load protection circuit, characterized in that, include: Both the first charging module and the second charging module charge based on the input power supply voltage; The first switch module and the second switch module are interconnected and respectively connected to the first charging module and the second charging module; The first charging module and the second charging module provide turn-on voltage to the first switching module and the second switching module, respectively, and the first charging module is configured to charge to the turn-on voltage before the second charging module; When the power supply voltage is connected, the first charging module is used to turn on the first switching module first, prioritizing it over the second charging module, so that the first switching module outputs the load voltage; the second switching module is used to turn off the first switching module based on its conduction, and to cut off the charging process of the second charging module to maintain the conduction of the first switching module. The second charging module is used to resume the charging process when the voltage at the output terminal of the first switching module drops due to the load short circuit. The second switching module is used to turn on based on the charging voltage of the second charging module to resume charging, and the first switching module is used to turn off based on the turned-on second switching module. When the load is de-short-circuited, the second charging module is used to maintain the charging process to keep the second switching module on, so that the first switching module remains in a locked off state.

2. The load protection circuit according to claim 1, characterized in that, The first charging module includes a first energy storage unit and a first impedance unit; The first end of the first energy storage unit is connected to the first switching module, the second end of the first energy storage unit is connected to the first end of the first impedance unit, and the second end of the first impedance unit is grounded. The control terminal of the first switching module is connected in parallel to both ends of the first energy storage unit, and the first energy storage unit is charged based on the supply voltage to provide a conduction voltage for the first switching module.

3. The load protection circuit according to claim 2, characterized in that, The load protection circuit also includes a power supply activation module, which is used to control the input of the power supply voltage. The second charging module includes a second energy storage unit, a second impedance unit, a third impedance unit, and a sampling resistor. The first end of the second energy storage unit is connected to the power supply module, the second end of the second energy storage unit is connected to the first end of the second impedance unit, the second end of the second impedance unit is connected to the first end of the third impedance unit, the second end of the third impedance unit is grounded, the sampling resistor is used to connect the output terminal of the first switching module and the load, the second end of the second impedance unit and the first end of the third impedance unit are also connected to the connection point of the sampling resistor and the first switching module, and the two ends of the second energy storage unit are also connected in parallel to the control terminal of the second switching module to provide the conduction voltage for the second switching module; At the instant the power supply voltage is applied, the second energy storage unit, the second impedance unit, and the third impedance unit form the first charging circuit of the second charging module; the first switching module is used to output the power supply voltage when it is turned on so that the voltages across the second energy storage unit are equal, thereby cutting off the charging process of the second energy storage unit in the first charging circuit; the resistance value of the third impedance unit is greater than the resistance value of the sampling resistor; When the load is short-circuited, the second energy storage unit, the second impedance unit, and the sampling resistor form a second charging circuit that is superior to the charging circuit of the first charging circuit. The second charging circuit is used to restore the charging process of the second charging module when the load is short-circuited, so as to turn on the second switching module. When the load is de-short-circuited, the second charging circuit is disconnected and the first charging circuit is used to maintain the charging process of the second charging module.

4. The load protection circuit according to claim 1, characterized in that, The first switching module includes a first switching transistor; The base and emitter of the first switching transistor are both connected to the first charging module, and the collector of the first switching transistor is used to connect to the load. The collector of the first switching transistor is also connected to the control terminal of the second switching module, and the base and emitter of the first switching transistor are connected to the output terminal of the second switching module.

5. The load protection circuit according to claim 1, characterized in that, The second switching module includes a second switching transistor; The base and emitter of the second switch are both connected to the second charging module, and the collector of the second switch is used to connect to the first switch module.

6. The load protection circuit according to claim 3, characterized in that, The power supply module includes an input switch, a voltage regulator module, and a third switch module. The first terminal of the input switch is supplied with a power supply voltage, and the second terminal of the input switch is connected to the voltage regulator module and the third switch module respectively; The voltage regulator module is connected between the source and gate of the third switch module. The drain of the third switch module is connected to the first charging module, the second charging module, the first switch module, and the second switch module, respectively. The voltage regulator module is used to drive the third switch module to conduct when the input switch is turned on, so that the supply voltage is transmitted to the first charging module, the second charging module, the first switch module, and the second switch module through the drain of the third switch module, respectively.

7. The load protection circuit according to claim 6, characterized in that, The voltage regulation and conduction module includes a fourth impedance unit, a fifth impedance unit, a sixth impedance unit, a seventh impedance unit, and a three-terminal voltage regulator; The first end of the fourth impedance unit, the first end of the sixth impedance unit, and the source of the third switching module are respectively connected to the second end of the input switch. The second end of the fourth impedance unit and the first end of the fifth impedance unit are respectively connected to the reference terminal of the three-terminal regulator. The second end of the fifth impedance unit and the anode of the three-terminal regulator are respectively grounded. The second end of the sixth impedance unit and the first end of the seventh impedance unit are respectively connected to the cathode of the three-terminal regulator. The second end of the seventh impedance unit is electrically connected to the gate of the third switching module.

8. The load protection circuit according to claim 3, characterized in that, The load protection circuit further includes an overcurrent detection module, the input and output terminals of which are respectively connected to the sampling resistor and the control terminal of the first switching module; The sampling resistor is used to sample the current signal at the output terminal of the first switching module that supplies power to the load, and is used to feed back an overcurrent signal when there is an overcurrent at the output terminal of the first switching module. The overcurrent detection module is used to control the first switching module to turn off based on the overcurrent signal.

9. The load protection circuit according to claim 8, characterized in that, The overcurrent detection module includes a first overcurrent switch module, a one-way conduction module, and a second overcurrent switch module. The control terminal and output terminal of the first overcurrent switch module are respectively connected to the sampling resistor and the input terminal of the unidirectional conduction module; The control terminal and output terminal of the second overcurrent switch module are respectively connected to the output terminal of the unidirectional conduction module and the control terminal of the first switch module; The first overcurrent switch module is used to turn on based on the overcurrent signal to output an overcurrent voltage, the unidirectional conduction module is used to unidirectionally conduct based on the overcurrent voltage to output an overcurrent control signal, and the second overcurrent switch module is used to turn on based on the overcurrent control signal to turn off the first switch module.

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

Images