Switching circuit with self-recovery short-circuit protection
By combining the MOSFET and the external circuit in the protection switching circuit, the problems of long response time, high power consumption and high cost of self-resetting fuses in short circuit protection are solved, realizing fast and recoverable short circuit protection, simplifying the circuit structure and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-25
- Publication Date
- 2026-03-31
AI Technical Summary
Existing resettable fuses have problems such as long response time, high additional power consumption, difficulty in recovery in low-voltage applications, and high cost in short-circuit protection. Traditional MOSFETs are easily damaged in high-speed output circuits and are inconvenient to replace.
By employing a protection switching circuit, the short-circuit protection is recoverable through a combination of a metal-oxide-semiconductor field-effect transistor (MOS transistor) and an external circuit. The control circuit detects the current threshold and switches the MOS transistor on and off, simplifying the circuit structure and improving the response speed.
It achieves non-one-time short-circuit protection, saves costs, improves system operating efficiency, simplifies circuit structure, and quickly restores normal circuit operation when a short circuit is recovered.
Smart Images
Figure CN224068638U_ABST
Abstract
Description
Technical Field
[0001] This invention relates to switching circuits, and more particularly to a switching circuit with self-resetting short-circuit protection. Background Technology
[0002] In modern electronic devices, the safety and reliability of power supply circuits are paramount. Short-circuit protection circuits, as a crucial safety mechanism, effectively prevent power supply damage caused by load short circuits or incorrect connections. Traditional short-circuit protection methods involve using fuses; when the current increases to the fuse's breaking current, the fuse overheats and blows, thus breaking the circuit. Later, resettable fuses were developed, which reconnect as the temperature decreases after blowing, automatically restoring power after the fault is cleared.
[0003] Switching devices are fundamental components in electronic and electrical systems. Their core function is to transmit, distribute, and convert electrical energy by controlling the on and off states of the switching element. The working principle of switching devices is based on the electrical properties of semiconductor materials. Taking a metal-oxide-semiconductor field-effect transistor (MOS transistor) as an example, it regulates the conduction state between the drain and source by controlling the gate voltage. MOS transistors include PMOS transistors and NMOS transistors. The source of a PMOS transistor is typically connected to a high potential (such as the positive terminal of a power supply), and the drain is connected to a low potential (such as the load terminal); the source of an NMOS transistor is typically connected to a low potential (such as ground), and the drain is connected to a high potential (such as the positive terminal of a power supply). For a PMOS transistor, when the gate voltage reaches a threshold, the PMOS transistor conducts, and current flows from the source to the drain; when the gate voltage is higher than the threshold, the PMOS transistor is off. For an NMOS transistor, when the gate voltage reaches a threshold, the NMOS transistor conducts, and current flows from the drain to the source; when the gate voltage is lower than the threshold, the NMOS transistor is off. This rapid switching characteristic enables the switching device to operate efficiently under high-frequency conditions, making it suitable for various applications such as switching power supplies and motor drives.
[0004] MOSFETs possess extremely fast switching speeds and efficient drive characteristics. Compared to traditional bipolar transistors, MOSFETs exhibit significant advantages in switching applications. The gate of a MOSFET is isolated from its current-conducting region by an insulating layer, meaning it does not require a continuous current to maintain its conduction state; once turned on, its drive current is almost zero. MOSFETs switch at extremely fast speeds, completing transitions from off to on or from on to off in nanoseconds or even less. This rapid switching capability makes them excellent for high-frequency applications, such as switching power supplies, motor drives, and high-frequency inverters.
[0005] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Utility Model Content
[0006] The inventors discovered that using a self-fusing fuse in series in a high-speed output circuit to achieve short-circuit protection has some limitations. For example, after a short-circuit fault causes the fuse to blow, the high-speed output channel is permanently damaged and unusable, requiring replacement with a new fuse, which is very inconvenient. When using a resettable fuse for short-circuit protection, the resettable fuse experiences a voltage drop during operation, resulting in additional power consumption and heat generation. Furthermore, the resettable fuse requires a relatively high voltage for its recovery process, which may limit its return to a low-resistance conducting state in low-voltage applications, thus preventing the circuit from functioning normally. In addition, in industrial environments, the resettable fuse has a long trip time. When a short-circuit fault occurs in the output circuit, the resettable fuse may not have activated before the output circuit switching elements have burned out, resulting in permanent damage to the output channel and rendering it unusable. If a higher-specification MOSFET is used to match the response time of the resettable fuse, these higher-specification MOSFETs are more expensive and larger, which is not conducive to cost reduction and miniaturization.
[0007] To address at least one of the aforementioned technical problems, embodiments of this application provide a switching circuit with self-recovering short-circuit protection. The short-circuit protection circuit in this switching circuit includes a protection switch circuit capable of switching between on and off states to control whether the voltage of the positive terminal of the power supply is supplied to the switching element, thereby providing non-one-time short-circuit protection, allowing the circuit to continue operating, saving costs, and improving system operating efficiency. Furthermore, the external circuit generates an operating voltage through the positive terminal of the power supply to turn on the protection switch circuit, which improves the recovery speed of the protection switch circuit and simplifies the circuit structure.
[0008] This application provides a switching circuit, including a short-circuit protection circuit and at least one switching element, wherein the short-circuit protection circuit is connected between the positive terminal of a power supply and at least one of the switching elements, and the short-circuit protection circuit includes:
[0009] A protective switching circuit, which is connected to the power supply terminal and the positive terminal of the power supply of the switching element; and
[0010] An external circuit is connected to the protection switch circuit and the positive terminal of the power supply to generate a working voltage that enables the protection switch circuit to conduct.
[0011] When the protection switch circuit is turned on, the positive terminal of the power supply applies voltage to the power supply terminal of the switching element through the protection switch circuit.
[0012] In some embodiments, the protection switch circuit has at least one metal-oxide-semiconductor field-effect transistor (MOSFET) connected to the positive terminal of the power supply and the corresponding switch element.
[0013] In some embodiments, the protection switch circuit has at least two metal-oxide-semiconductor field-effect transistors, and the number of switching elements is also at least two, with each metal-oxide-semiconductor field-effect transistor connected to a corresponding switching element.
[0014] In some embodiments, the metal-oxide-semiconductor field-effect transistor has an input terminal, an enable terminal, and an output terminal.
[0015] The input terminal is connected to the positive terminal of the power supply.
[0016] The enable terminal is connected to the peripheral circuit and receives the operating voltage.
[0017] The output terminal is connected to the corresponding switching element.
[0018] In some embodiments, the protection switch circuit has a voltage input terminal, and the input terminals of each of the metal-oxide-semiconductor field-effect transistors are connected to the positive terminal of the power supply through the voltage input terminal;
[0019] The protection switch circuit has at least one operating voltage input terminal, and the enable terminal of each metal-oxide-semiconductor field-effect transistor receives the operating voltage through the corresponding operating voltage input terminal;
[0020] The protection switch circuit has at least one voltage output terminal, and the output terminals of each metal-oxide-semiconductor field-effect transistor are connected to the corresponding switching element through the corresponding voltage output terminal.
[0021] In some embodiments, the protection switch circuit further includes a control circuit.
[0022] The control circuit is connected to the metal-oxide-semiconductor field-effect transistor (MOSFET). When the current of the MOSFET is detected to be greater than or equal to a threshold, the MOSFET is turned off, and the output terminal of the MOSFET stops providing voltage to the corresponding switching element.
[0023] In some embodiments, when the control circuit detects that the current of the metal-oxide-semiconductor field-effect transistor is less than the threshold, it turns on the metal-oxide-semiconductor field-effect transistor, and the output terminal of the metal-oxide-semiconductor field-effect transistor provides a voltage to the corresponding switching element.
[0024] In some embodiments, the peripheral circuit includes:
[0025] First resistor and second resistor
[0026] The first resistor and the second resistor are connected in series between the positive terminal of the power supply and the ground terminal, and the connection point of the first resistor and the second resistor is connected to the protection switch circuit to provide the operating voltage to the protection switch circuit.
[0027] In some embodiments, the switching circuit further includes:
[0028] At least one driving circuit, each driving circuit being connected to a corresponding switching element, amplifies the received driving signal, and applies the amplified driving signal to the corresponding switching element to control the switching element to turn on or off.
[0029] In some embodiments, the protection switch circuit is a high-side switch.
[0030] The beneficial effects of this invention are as follows: the protection switch circuit can switch between being on and off, thereby providing short-circuit protection in a non-one-time manner, allowing the circuit to continue to be used, saving costs, improving system operating efficiency, and the peripheral circuit generates a working voltage that enables the protection switch circuit to conduct through the positive terminal of the power supply, which can improve the recovery speed of the protection switch circuit and simplify the circuit structure.
[0031] Specific embodiments of the invention are disclosed in detail with reference to the following description and accompanying drawings, indicating how the principles of the invention can be employed. It should be understood that the embodiments of the invention are not therefore limited in scope. Within the spirit and scope of the appended claims, embodiments of the invention include many changes, modifications, and equivalents.
[0032] Features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.
[0033] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, whole, step, or component, but does not exclude the presence or addition of one or more other features, wholes, steps, or components. Attached Figure Description
[0034] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the embodiments of the invention and illustrate implementation methods, and together with the textual description, explain the principles of the invention. Obviously, the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort. In the drawings:
[0035] Figure 1 This is a schematic diagram of a switching circuit according to an embodiment of this application;
[0036] Figure 2 This is a circuit structure diagram of a switching circuit according to an embodiment of this application;
[0037] Figure 3 This is a partial circuit diagram of the connection between the MOSFET and the switching element in the protection switch circuit of this application embodiment;
[0038] Figure 4 This is another part of the circuit diagram showing the connection between the MOS transistor and the switching element in the protection switch circuit of this application embodiment;
[0039] Figure 5 This is a partial structural diagram of the protection switch circuit according to an embodiment of this application;
[0040] Figure 6 This is a schematic diagram of a protection switch circuit according to an embodiment of this application;
[0041] Figure 7 This is a connection diagram of the driving circuit according to an embodiment of this application. Detailed Implementation
[0042] Referring to the accompanying drawings, the foregoing and other features of the invention will become apparent from the following description. Specific embodiments of the invention are specifically disclosed in the description and drawings, illustrating partial implementations in which the principles of the invention can be employed. It should be understood that the invention is not limited to the described embodiments; rather, it includes all modifications, variations, and equivalents falling within the scope of the appended claims.
[0043] In the embodiments of this application, the terms "first," "second," etc., are used to distinguish different elements by name, but do not indicate the spatial arrangement or chronological order of these elements, and these elements should not be limited by these terms. The term "and / or" includes any one or more of the terms listed in association and all combinations thereof. The terms "comprising," "including," "having," etc., refer to the presence of the stated features, elements, components, or assemblies, but do not exclude the presence or addition of one or more other features, elements, components, or assemblies.
[0044] In the embodiments of this application, the singular forms "a," "the," etc., including the plural forms, should be broadly understood as "a kind" or "a class" rather than limited to the meaning of "an." Furthermore, the term "the" should be understood to include both the singular and plural forms, unless the context explicitly indicates otherwise. Additionally, the term "according to" should be understood as "at least partially based on…," and the term "based on" should be understood as "at least partially based on…," unless the context explicitly indicates otherwise.
[0045] Features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments. The term "comprising / including" as used herein means the presence of a feature, integral, step, or component, but does not exclude the presence or addition of one or more other features, integrals, steps, or components.
[0046] The embodiments of this application will be described in detail below with reference to the accompanying drawings.
[0047] This application provides a switching circuit, including a short-circuit protection circuit and at least one switching element.
[0048] Figure 1 This is a schematic diagram of the switching circuit in this embodiment. For example... Figure 1 As shown, the switching circuit 10 includes a short-circuit protection circuit 1 and a switching element 2. The short-circuit protection circuit 1 is connected between the positive terminal of the power supply 3 and at least one switching element 2. In the switching circuit 10, the short-circuit protection circuit 1 includes a protection switching circuit 101 and an external circuit 102.
[0049] Figure 2 This is a circuit structure diagram of a switching circuit according to an embodiment of this application. For example... Figure 2 As shown, the protection switch circuit 101 is connected to the power supply terminal and the positive terminal 3 of the switching element 2 respectively. The peripheral circuit 102 is connected to the protection switch circuit 101 to generate a working voltage that turns on the protection switch circuit 101. When the protection switch circuit 101 is turned on, the positive terminal 3 of the power supply applies a voltage to the power supply terminal of the switching element 2 through the protection switch circuit 101.
[0050] In this embodiment, the protection switch circuit 101 is described as a high-side switch (HSD). The same description applies to embodiments where the protection switch circuit 101 is not a high-side switch. A high-side switch is a switching device used to control the high-voltage side (typically the power supply side) of a circuit, primarily controlling the power supply to the load by controlling the conduction and cutoff of switching elements (e.g., MOSFETs).
[0051] The protection switch circuit of this application will be described below.
[0052] In some embodiments, the protection switch circuit 101 may have at least one metal-oxide-semiconductor field-effect transistor, i.e., a MOS transistor.
[0053] Figure 3 This is a partial circuit diagram showing the connection between the MOSFET and the switching element in the protection switch circuit of this application embodiment. For example... Figure 3 As shown, the protection switch circuit 101 has at least one MOSFET 30, which is connected to the positive terminal of the power supply 3 and the corresponding switching element 2. For example, the MOSFET 30 can be a PMOS transistor or an NMOS transistor. This application does not limit this, but this application uses a PMOS transistor as an example for illustration.
[0054] like Figure 3 As shown, the MOSFET 30 has an input terminal 301 (source), an enable terminal 302 (gate), and an output terminal 303 (drain). The input terminal 301 is connected to the positive power supply 3; the enable terminal 302 is connected to the external circuit 102 and receives the operating voltage; the output terminal 303 is connected to the corresponding switching element 2. For example, the output terminal 303 is connected to the input terminal of the corresponding switching element 2. For instance, if the switching element 2 is a high-speed MOSFET (e.g., a PMOS transistor), the output terminal 303 can be connected to the source of the switching element 2.
[0055] In other embodiments, the protection switch circuit 101 has at least two metal-oxide-semiconductor field-effect transistors, and the number of switching elements is also at least two, with each metal-oxide-semiconductor field-effect transistor connected to a corresponding switching element 2.
[0056] Figure 4 This is another part of the circuit diagram showing the connection between the MOSFET and the switching element in the protection switch circuit of this application embodiment. For example... Figure 4 As shown, the protection switch circuit 101 has MOSFET 30a and MOSFET 30b, and the switching element 2 includes switching element 21 and switching element 22. In the protection switch circuit 101, MOSFET 30a is connected to switching element 21, and MOSFET 30b is connected to switching element 22.
[0057] Figure 5 This is a partial structural diagram of the protection switch circuit according to an embodiment of this application, and... Figure 2 The corresponding implementation example.
[0058] exist Figure 2 In this configuration, at least one switching element 2 includes: switching element TR1, switching element TR2, switching element TR3, and switching element TR4. Figure 5In the protection switch circuit 101, there are at least two MOSFETs (e.g., four MOSFETs), including MOSFET 31, MOSFET 32, MOSFET 33 and MOSFET 34. MOSFET 31 is connected to switch element TR1; MOSFET 32 is connected to switch element TR2; MOSFET 33 is connected to switch element TR3; and MOSFET 34 is connected to switch element TR4.
[0059] In the switching circuit 10 of this application, the number of switching elements 2 is equal to the number of MOSFETs in the protection switching circuit 101. Therefore, multiple switching elements 2 can be individually protected against short circuits, improving the reliability of the short circuit protection. The quantities shown in the figures are for reference only; this application does not limit the number of switching elements 2 or the number of MOSFETs.
[0060] In some embodiments, the protection switch circuit 101 has a voltage input terminal, through which the input terminals of each MOSFET in the protection switch circuit 101 are connected to the positive terminal of the power supply 3; the protection switch circuit 101 has at least one operating voltage input terminal, through which the enable terminal of each MOSFET receives the operating voltage; the protection switch circuit 101 has at least one voltage output terminal, through which the output terminal of each MOSFET is connected to the corresponding switching element 2. The protection switch circuit 101 controls whether to supply the voltage of the positive terminal of the power supply 3 to the corresponding switching element 2 by controlling the turning on and off of the MOSFETs, thereby providing short-circuit protection and ensuring a small residual voltage in the output circuit.
[0061] For example, such as Figure 2 and Figure 5As shown, the voltage input terminal VIN of the protection switch circuit 101 is connected to the positive terminal of the power supply 3. Furthermore, the input terminals (e.g., sources) of MOSFETs 31, 32, 33, and 34 are each connected to the voltage input terminal VIN. The operating voltage input terminals of the protection switch circuit 101 can be four or other numbers, labeled EN4, EN3, EN2, and EN1 respectively. All operating voltage input terminals are connected to the external circuit 102 and receive the same operating voltage. Additionally, the enable terminals (e.g., gates) of MOSFETs 31, 32, 33, and 34 are respectively connected to the operating voltage input terminals EN1, EN2, EN3, and EN4. The voltage output terminals of circuit 101 can be four or other numbers, labeled VOUT4, VOUT3, VOUT2 and VOUT1 respectively, and connected to the corresponding switching elements TR4, TR3, TR2 and TR1 respectively. For example, the voltage output terminals VOUT4, VOUT3, VOUT2 and VOUT1 are connected to the source of the corresponding switching element TR4, the source of TR3, the source of TR2 and the source of TR1 respectively. In addition, the output terminals (e.g., drains) of MOSFETs 31, 32, 33 and 34 are connected to the voltage output terminals VOUT1, VOUT2, VOUT3 and VOUT4 respectively.
[0062] like Figure 2 and Figure 5 As shown, the MOSFETs of the protection switch circuit 101 are connected to corresponding switching elements for switching on and off. This allows for simultaneous short-circuit protection of multiple output circuits, with each circuit controllable independently without interference.
[0063] This application does not restrict the position of each switching element or the position of each MOSFET. For example, the positions of the switching elements and MOSFETs can be interchanged, and this application is not limited to this. The correspondence between the switching elements and MOSFETs can also be changed, and this application is not limited to this. For example, MOSFET 32 corresponds to switching element TR3, and MOSFET 33 corresponds to switching element TR2. In this case, MOSFET 32 controls the short-circuit protection of the branch circuit containing switching element TR3, and MOSFET 33 controls the short-circuit protection of the branch circuit containing switching element TR2. Alternatively, the output terminals of MOSFETs 32 and MOSFET 33 can be connected to a single switching element. In this case, MOSFETs 32 and MOSFET 33 jointly control the short-circuit protection of the branch circuit containing switching element TR3. A one-to-one correspondence or multiple MOSFETs corresponding to one switching element can be implemented, and this application is not limited to this.
[0064] Figure 6 This is a schematic diagram of a protection switch circuit according to an embodiment of this application. Figure 6As shown, the protection switch circuit also includes a control circuit 50. When the control circuit 50 detects that the current of the MOSFET 30 is greater than or equal to a threshold, it turns off the MOSFET 30, and the output terminal 303 of the MOSFET 30 stops providing voltage to the corresponding switching element 2. When the control circuit 50 detects that the current of the MOSFET 30 is less than the threshold, it turns on the MOSFET 30, so that the output terminal 303 of the MOSFET 30 provides voltage to the switching element. The protection switch circuit integrates a short-circuit detection circuit. When a short circuit is detected in the load, the switch closes the circuit. When the short-circuit fault is cleared, no short-circuit protection feedback signal is needed, and the circuit is automatically reconnected, realizing self-recoverable short-circuit protection.
[0065] For example, control circuit 50 is connected to the enable terminal 302 of MOSFET 30. Control circuit 50 can detect the current flowing through MOSFET 30. When a short circuit occurs in the circuit connected to switching element 2, the current increases. When the current exceeds a preset threshold, control circuit 50 sets enable terminal 302 to 0, thereby turning off output terminal 303 and stopping the supply of voltage to the corresponding switching element 2, thus achieving short circuit protection. Alternatively, other methods can be used to prevent the output terminal from supplying voltage to switching element 2, thereby achieving short circuit protection. For overcurrent detection and short circuit protection of high-side switches, please refer to existing technologies; this embodiment will not elaborate further.
[0066] For example, when the control circuit 50 detects that the current of the MOSFET 30 is less than the threshold, such as after the short circuit fault is cleared, the control circuit 50 sets the enable terminal 302 to 1 or restores the voltage to the switching element 2, so that the MOSFET 30 is turned on and the switching circuit is turned on.
[0067] The protection switch circuit of this application has been described above. The peripheral circuit of this application will be described below.
[0068] like Figure 2 As shown, the peripheral circuit includes a first resistor R1 and a second resistor R2. The first resistor R1 and the second resistor R2 are connected in series between the positive terminal 3 of the power supply and the ground terminal 4. Furthermore, the connection point of the first resistor R1 and the second resistor R2 is connected to the protection switch circuit 101 to provide the operating voltage of the protection switch circuit 101.
[0069] The first resistor R1 divides the voltage to prevent the protection switch circuit 101 from being directly connected to the power supply, while the second resistor R2 provides the operating voltage for the protection switch circuit 101.
[0070] The first resistor R1 prevents the protection switch circuit from malfunctioning due to excessive user voltage fluctuations by performing voltage division; the second resistor R2 provides the operating voltage to the protection switch circuit, keeping it in the ON state. Since the protection switch circuit 101 always has an operating voltage and is in an operational state, it can quickly conduct when a short circuit recovery occurs, resulting in low on-resistance and low residual voltage.
[0071] For example, when the switching circuit of this application is used in different scenarios, the output voltage of the power supply will be different. The presence of the first resistor R1 can achieve voltage division, thereby controlling the voltage of the protection switching circuit within a certain range, so as not to burn out the protection switching circuit. The presence of the second resistor R2 provides the operating voltage for the protection switching circuit, enabling the protection switching circuit to work normally.
[0072] The peripheral circuit of this application has been described above. The switching element and drive circuit of this application will be described below.
[0073] The switching element can be a high-speed MOSFET, which can achieve extremely fast switching speed. By optimizing the gate capacitance and drive circuit design, rapid turn-on and turn-off can be achieved. The specific design of the drive circuit can refer to the existing technology, and will not be described in detail in this embodiment.
[0074] Figure 7 This is a connection diagram of the driving circuit according to an embodiment of this application. Figure 1 and Figure 7 As shown, the switching circuit 10 also includes at least one driving circuit 60. Each driving circuit 60 is connected to the corresponding switching element 2. The driving circuit amplifies the received driving signal and applies the amplified driving signal to the corresponding switching element to control the switching element to turn on or off.
[0075] like Figure 2 As shown, the driving circuit 60 can be, for example, Figure 2 The driving circuit 61, driving circuit 62, driving circuit 63, or driving circuit 64, and the switching element 2 may be, for example, a driving circuit 64. Figure 2 The switching elements are TR1, TR2, TR3, or TR4. In some examples, drive circuit 61 is connected to the enable terminal (e.g., gate) of switching element TR1, drive circuit 62 is connected to the enable terminal (e.g., gate) of switching element TR2, drive circuit 63 is connected to the enable terminal (e.g., gate) of switching element TR3, and drive circuit 64 is connected to the enable terminal (e.g., gate) of switching element TR4. Each of these circuits controls the on or off state of its corresponding switching element. They can be controlled simultaneously or separately. The drive circuits and the switching elements together function as controllable switches.
[0076] The above embodiments are merely illustrative examples of embodiments of this application, but this application is not limited thereto, and appropriate modifications can be made based on the above embodiments. For example, the above embodiments can be used alone, or one or more of the above embodiments can be combined.
[0077] The present application has been described above with reference to specific embodiments. However, those skilled in the art should understand that these descriptions are exemplary and not intended to limit the scope of protection of the present application. Those skilled in the art can make various modifications and variations to the present application based on its spirit and principles, and these modifications and variations are also within the scope of the present application. As used herein, the term "exemplary" means used as a non-limiting example, instance, or illustration. As used herein, the term "for example" refers to a list of one or more non-limiting examples, instances, or illustrations.
[0078] Preferred embodiments of this application have been described above with reference to the accompanying drawings. Many features and advantages of these embodiments are apparent from this detailed description, and therefore the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Furthermore, since many modifications and alterations will readily occur to those skilled in the art, the embodiments of this application are not intended to be limited to the precise structures and operations illustrated and described, but rather to encompass all suitable modifications and equivalents falling within their scope.
Claims
1. A switching circuit comprising a short-circuit protection circuit and at least one switching element, wherein, The short-circuit protection circuit is connected between the positive pole of the power supply and at least one of the switching elements, characterized in that the short-circuit protection circuit comprises: a protection switch circuit connected to the power supply positive pole and the power supply terminal of the switching element; and a peripheral circuit connected to the protection switch circuit and the power supply positive pole, generating an operating voltage to turn on the protection switch circuit; When the protection switch circuit is turned on, the power supply positive pole applies a voltage to the power supply terminal of the switching element through the protection switch circuit.
2. The switching circuit of claim 1, wherein The protection switch circuit has at least one metal oxide semiconductor field effect transistor connected to the power supply positive pole and the corresponding switching element.
3. The switching circuit of claim 2, wherein The protection switch circuit has at least two metal oxide semiconductor field effect transistors, and the number of switching elements is also at least two, and each metal oxide semiconductor field effect transistor is connected to the corresponding switching element.
4. The switching circuit of claim 2, wherein The metal oxide semiconductor field effect transistor has an input terminal, an enable terminal and an output terminal, The input terminal is connected to the power supply positive pole, The enable terminal is connected to the peripheral circuit to receive the operating voltage, The output terminal is connected to the corresponding switching element.
5. The switching circuit of claim 4, characterized in that: The protection switch circuit has a voltage input terminal, and the input terminal of each metal oxide semiconductor field effect transistor is connected to the power supply positive pole through the voltage input terminal; The protection switch circuit has at least one operating voltage input terminal, and the enable terminal of each metal oxide semiconductor field effect transistor receives the operating voltage through the corresponding operating voltage input terminal; The protection switch circuit has at least one voltage output terminal, and the output terminal of each metal oxide semiconductor field effect transistor is connected to the corresponding switching element through the corresponding voltage output terminal.
6. The switching circuit of claim 4, wherein The protection switch circuit further has a control circuit, The control circuit is connected to the metal oxide semiconductor field effect transistor, and when it is detected that the current of the metal oxide semiconductor field effect transistor is greater than or equal to a threshold value, the metal oxide semiconductor field effect transistor is turned off, and the output terminal of the metal oxide semiconductor field effect transistor stops providing voltage to the corresponding switching element.
7. The switching circuit of claim 6, wherein When the control circuit detects that the current of the metal oxide semiconductor field effect transistor is less than the threshold value, the metal oxide semiconductor field effect transistor is turned on, and the output terminal of the metal oxide semiconductor field effect transistor provides voltage to the corresponding switching element.
8. The switching circuit of claim 1, wherein, The peripheral circuit comprises: a first resistor and a second resistor, The first resistor and the second resistor are connected in series between the power supply positive pole and the ground terminal, and the connection point of the first resistor and the second resistor is connected to the protection switch circuit to provide the operating voltage for the protection switch circuit.
9. The switching circuit of claim 1, characterized in that, The switching circuit further comprises: At least one drive circuit, each of the drive circuits being connected to a corresponding one of the switching elements, amplifying a received drive signal, and applying the amplified drive signal to the corresponding one of the switching elements to control conduction or non-conduction of the corresponding one of the switching elements.
10. The switching circuit of claim 1, wherein, The protection switching circuit is a high-side switch.