Output overvoltage protection circuit of Buck circuit and computing device

Abstract

The invention provides an output overvoltage protection circuit of a Buck circuit and computing equipment, and the output overvoltage protection circuit comprises a detection circuit which is coupled with the Buck circuit and a controller, and is used for monitoring a target voltage signal of the Buck circuit in real time, and transmitting the target voltage signal to the controller; the controller is used for determining the switching state of the first switching tube based on the target voltage signal; and when it is determined that the first switching tube is continuously short-circuited, the second switching tube is controlled to be switched on, so that the first switching tube and the second switching tube form a straight-through path to clamp the output voltage of the Buck circuit. According to the scheme, the second switching tube is controlled to be switched on to form a direct-connection path of the input power supply, and the risk that the input voltage of the Buck circuit is directly connected to the output end can be thoroughly eliminated. And the second switching tube is reused to replace a TVS device, so that the circuit cost can be reduced, meanwhile, the risk that the PCB is burnt out due to continuous high temperature caused by the fact that the TVS enters a low resistance state due to incomplete breakdown is avoided, and the reliability is improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of server technology, and in particular to an output overvoltage protection circuit of a Buck circuit and a computing device. Background Art

[0002] In buck circuit applications, a short-circuit failure of the high-side transistor (SST) can cause the voltage input to the buck circuit (step-down circuit) to flow directly to the buck circuit's voltage output, resulting in a serious output overvoltage problem. This SST short-circuit failure poses a significant threat to critical loads downstream of the buck circuit, such as the central processing unit (CPU), graphics processing unit (GPU), and storage devices, potentially causing hardware damage or loss of critical data.

[0003] Traditional protection solutions, if not implemented, can directly lead to the failure of critical loads. Furthermore, if transient voltage suppressors (TVS) tubes, typically designed for low-power applications, are used in high-power scenarios, they can cause incomplete breakdown of the TVS, resulting in a low-resistance state and the risk of persistent high temperatures and burnout of the printed circuit board (PCB), leading to low reliability. Therefore, an efficient and highly reliable overvoltage protection solution for high-power buck circuits is urgently needed to protect critical downstream loads. Summary of the Invention

[0004] The embodiments of the present application provide an output overvoltage protection circuit and computing device for a Buck circuit, which can achieve highly reliable overvoltage protection in high-power scenarios by addressing the problem of insufficient reliability of existing TVS tube protection solutions.

[0005] To achieve the above objectives, the present invention adopts the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides an output overvoltage protection circuit for a Buck circuit, wherein the Buck circuit includes a first switch tube, a second switch tube, and an inductor, wherein the inductor is coupled between a first common node of the Buck circuit and a voltage output end of the Buck circuit, and the first switch tube is coupled between a voltage input end of the Buck circuit and the first common node; the second switch tube is coupled between the first common node and ground; the output overvoltage protection circuit for the Buck circuit includes: a detection circuit coupled to the Buck circuit and a controller, for obtaining a target voltage signal of the Buck circuit and transmitting the target voltage signal to the controller; a controller for determining a switching state of the first switch tube based on the target voltage signal; when it is determined that the first switch tube is continuously short-circuited, controlling the second switch tube to turn on so that the first switch tube and the second switch tube form a straight-through path to clamp the output voltage of the Buck circuit; wherein, when the first switch tube is short-circuited and the duration of the short circuit is greater than or equal to a preset duration, it is determined that the first switch tube is continuously short-circuited.

[0007] Based on this solution, when the controller determines that the first switch is continuously short-circuited, it controls the second switch to conduct, creating a direct path for the input power. This clamps the output voltage of the buck circuit, completely eliminating the risk of the buck circuit input voltage passing directly through to the output. Furthermore, by reusing the second switch in place of a TVS device, circuit costs are reduced while also avoiding the risk of the TVS incompletely breaking down and entering a low-resistance state, which could cause persistent high temperatures and damage the PCB. This improves reliability and effectively protects critical downstream loads.

[0008] In some embodiments of the present application, the Buck circuit also includes a soft-start circuit coupled between the voltage input terminal of the Buck circuit and the first switch tube; a controller is coupled to the soft-start circuit and is used to generate and send a shutdown signal to the soft-start circuit when it is determined that the first switch tube is short-circuited; the soft-start circuit is used to disconnect the voltage input terminal of the Buck circuit and the first switch tube in response to the shutdown signal to cut off the input voltage of the Buck circuit.

[0009] Based on this solution, when the Buck circuit includes a soft-start circuit and the controller determines that the first switch is short-circuited, it first controls the soft-start circuit to shut off, thereby cutting off the input voltage. If this input voltage cutoff fails to clamp the Buck circuit's output voltage in time, that is, if the first switch remains short-circuited, the controller controls the second switch to conduct, creating a direct path for the input power. This approach not only eliminates the risk of sustained overvoltage at the source but also minimizes damage to the second switch while clamping the Buck circuit's output voltage.

[0010] In some embodiments of the present application, the target voltage signal includes a first voltage detection signal; the detection circuit includes a first voltage divider circuit corresponding to the first voltage detection signal, the first voltage divider circuit is used to detect the voltage on the first voltage divider node in the first voltage divider circuit, and transmit the obtained first voltage detection signal to the controller; the controller is used to determine the switching state of the first switching tube based on the first voltage detection signal.

[0011] Based on this solution, when the voltage on the first voltage-dividing node in the first voltage-dividing circuit can accurately reflect the conduction state of the first switching tube, the first voltage-dividing circuit detects the voltage on the first voltage-dividing node and transmits the obtained first voltage detection signal to the controller, so that the controller can accurately determine whether the switching state of the first switching tube is an abnormal short circuit based on the first voltage detection signal.

[0012] In some embodiments of the present application, the controller is specifically used to determine the voltage signal on the first common node based on the first voltage detection signal; when the voltage signal on the first common node is converted from a first level to a second level, and the duration of the second level is greater than or equal to the first duration, it is determined that the first switch tube is short-circuited; when the voltage signal on the first common node continues at the second level for a duration greater than or equal to a second duration, it is determined that the first switch tube is continuously short-circuited; wherein, the second duration is greater than the first duration.

[0013] Based on this solution, when the voltage signal on the first common node is at a first level, indicating that the first switch is off, and when the voltage signal on the first common node is at a second level, indicating that the first switch is on, and the first duration is greater than or equal to the duty cycle of the first switch, the controller can accurately determine that the first switch is short-circuited if the voltage signal on the first common node transitions from the first level to the second level, and the duration of the second level is greater than or equal to the first duration. When the duration of the second level is greater than or equal to the second duration, and the second duration is greater than the first duration, the controller can accurately determine that the first switch is continuously short-circuited.

[0014] In some embodiments of the present application, the first voltage divider circuit includes a first resistor, a second resistor, a third resistor, and a first capacitor. One end of the first resistor is coupled to a first common node, the other end of the first resistor is coupled to one end of the second resistor, and the other end of the second resistor is grounded. The connection point between the first resistor and the second resistor is a first voltage divider node, which is also coupled to a controller. The third resistor and the first capacitor are connected in parallel between the first voltage divider node and ground.

[0015] Based on this solution, the voltage on the first common node can be detected by the voltage divider circuit composed of the first resistor and the second circuit, and by connecting the third resistor and the first capacitor in parallel between the first voltage divider node between the first resistor and the second resistor and the ground, not only the amplitude of the first voltage detection signal can be stabilized, but also the high-frequency interference of the detected first voltage detection signal can be removed.

[0016] In some embodiments of the present application, the target voltage signal includes a first voltage detection signal and a second voltage detection signal; the detection circuit includes a first voltage divider circuit corresponding to the first voltage detection signal and a second voltage divider circuit corresponding to the second voltage detection signal; the first voltage divider circuit is used to monitor the voltage on the first voltage divider node in the first voltage divider circuit in real time, and transmit the obtained first voltage detection signal to the controller; the second voltage divider circuit is used to monitor the voltage on the second voltage divider node in the second voltage divider circuit in real time, and transmit the obtained second voltage detection signal to the controller; the controller is used to determine the switching state of the first switching tube based on the first voltage detection signal and the second voltage detection signal.

[0017] Based on this solution, when the voltage on the first voltage-dividing node in the first voltage-dividing circuit can accurately reflect the conduction state of the first switching tube, and the voltage on the second voltage-dividing node in the second voltage-dividing circuit can accurately reflect the control end of the second switching tube, the first voltage-dividing circuit detects the voltage on the first voltage-dividing node and transmits the obtained first voltage detection signal to the controller, and the second voltage-dividing circuit detects the voltage on the second voltage-dividing node and transmits the obtained second voltage detection signal to the controller, the controller can accurately determine whether the switching state of the first switching tube is an abnormal short circuit based on the first voltage detection signal and the second voltage detection signal.

[0018] In some embodiments of the present application, the controller is used to determine the voltage signal on the first common node based on the first voltage detection signal; determine the voltage signal on the control end of the second switch tube based on the second voltage detection signal; determine that the first switch tube is short-circuited when the voltage signal on the control end of the second switch tube is a second level and the amplitude of the voltage signal on the first common node is greater than the first voltage threshold; determine that the first switch tube is continuously short-circuited when the voltage signal on the control end of the second switch tube is a second level and the amplitude of the voltage signal on the first common node is greater than the second voltage threshold; wherein the second voltage threshold is greater than the first voltage threshold.

[0019] Based on this solution, since the voltage signal at the control terminal of the second switch is at the second level, indicating that the second switch is conducting, that is, during the freewheeling phase, the voltage signal at the first common node must be less than the conduction voltage drop of the second switch. Therefore, when the first voltage threshold is greater than or equal to the conduction voltage drop of the second switch, the controller can accurately determine that the first switch is short-circuited when the voltage signal at the control terminal of the second switch is at the second level, the amplitude of the voltage signal at the first common node is greater than the first voltage threshold, and the first voltage threshold is the conduction voltage drop of the second switch. When the voltage signal at the control terminal of the second switch is at the second level, the amplitude of the voltage signal at the first common node is greater than the second voltage threshold, and the second voltage threshold is greater than the first voltage threshold, the controller can accurately determine that the first switch is continuously short-circuited.

[0020] In some embodiments of the present application, the target voltage signal includes a third voltage detection signal; the detection circuit includes a third voltage divider circuit corresponding to the third voltage detection signal; the third voltage divider circuit is used to monitor the voltage on the third voltage divider node in the third voltage divider circuit in real time, and transmit the obtained third voltage detection signal to the controller; the controller is used to determine the switching state of the first switching tube based on the third voltage detection signal.

[0021] Based on this solution, when the voltage on the third voltage-dividing node in the third voltage-dividing circuit can accurately reflect the conduction state of the first switching tube, the third voltage-dividing circuit detects the voltage on the third voltage-dividing node and transmits the obtained third voltage detection signal to the controller, so that the controller can accurately determine whether the switching state of the first switching tube is an abnormal short circuit based on the third voltage detection signal.

[0022] In some embodiments of the present application, the controller is used to determine the voltage signal at the voltage output end of the Buck circuit based on the third voltage detection signal; when the voltage signal at the voltage output end of the Buck circuit is greater than the third voltage threshold, determine that the first switch tube is short-circuited; when the voltage signal at the voltage output end of the Buck circuit is greater than the fourth voltage threshold, determine that the first switch tube is continuously short-circuited; wherein the fourth voltage threshold is greater than the third voltage threshold.

[0023] Based on this solution, when the third voltage threshold can reflect the maximum voltage that the important load at the back end of the Buck circuit can withstand, the controller can accurately determine that the first switch has a short circuit when the amplitude of the third voltage detection signal is greater than the third voltage threshold. Furthermore, when the amplitude of the third voltage detection signal is greater than the fourth voltage threshold, and the fourth voltage threshold is greater than the third voltage threshold, the controller can accurately determine that the first switch is continuously short-circuited.

[0024] In the second aspect, an embodiment of the present application provides an output overvoltage protection method for a Buck circuit, which is applied to the controller in the output overvoltage protection circuit of the Buck circuit provided in the first aspect above. The method includes: obtaining a target voltage signal of the Buck circuit; determining the switching state of a first switch tube based on the target voltage signal; when it is determined that the first switch tube is continuously short-circuited, controlling the second switch tube to turn on, so that the first switch tube and the second switch tube form a straight-through path to clamp the output voltage of the Buck circuit.

[0025] In a third aspect, an embodiment of the present application provides an output overvoltage protection device for a Buck circuit, which includes: an acquisition module for acquiring a target voltage signal of the Buck circuit; a determination module for determining the switching state of a first switch tube based on the target voltage signal; and a control module for controlling the second switch tube to turn on when it is determined that the first switch tube is continuously short-circuited, so that the first switch tube and the second switch tube form a straight-through path to clamp the output voltage of the Buck circuit.

[0026] In a fourth aspect, an embodiment of the present application provides a computing device, which includes a Buck circuit and an output overvoltage protection circuit of the Buck circuit.

[0027] In a fifth aspect, an embodiment of the present application provides a storage medium storing a computer program for executing the output overvoltage protection method for the Buck circuit provided in the second aspect above.

[0028] In a sixth aspect, an embodiment of the present application provides a computer program product. When the instructions in the computer program product are executed by a processor, the output overvoltage protection method of the Buck circuit provided in the first aspect above is executed. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1A A schematic diagram of the structure of a Buck circuit provided in an embodiment of the present application.

[0030] Figure 1B This is a schematic diagram of the structure of another Buck circuit provided in an embodiment of the present application.

[0031] Figure 2 This is a schematic diagram of the structure of an output overvoltage protection circuit of a Buck circuit provided in an embodiment of the present application.

[0032] Figure 3 A schematic diagram of the structure of an output overvoltage protection circuit of another Buck circuit provided in an embodiment of the present application.

[0033] Figure 4This is a schematic diagram of the structure of an output overvoltage protection circuit of another Buck circuit provided in an embodiment of the present application.

[0034] Figure 5 This is a schematic diagram of the structure of an output overvoltage protection circuit of another Buck circuit provided in an embodiment of the present application.

[0035] Figure 6 This is a schematic diagram of the structure of an output overvoltage protection circuit of another Buck circuit provided in an embodiment of the present application.

[0036] Figure 7 A flowchart of an output overvoltage protection method for a Buck circuit provided in an embodiment of the present application.

[0037] Figure 8 This is a schematic diagram of the structure of an output overvoltage protection device for a Buck circuit provided in an embodiment of the present application.

[0038] Figure 9 A schematic diagram of the structure of a computing device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The following will describe the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings. To facilitate the clear description of the technical solutions in the embodiments of the present application, the first, second, etc. descriptions in the embodiments of the present application are only used for illustration and to distinguish the described objects. There is no order, nor does it represent a special limitation on the number of devices in the embodiments of the present application, and it does not constitute any limitation on the embodiments of the present application.

[0040] The following is an explanation of the relevant technical terms in the embodiments of this application:

[0041] Buck circuit is a DC-DC switching power supply topology used to reduce the input DC voltage Vin to a lower output DC voltage Vout. Buck circuit can be set in the power supply unit (power supply unit) of computing equipment. upp lyu n It is used in the PSU to pre-step down the high-voltage DC signal output by the power factor correction (PFC). It can also be set on the motherboard of the computing device to convert the output voltage of the PSU into chip-level voltage to meet the voltage requirements of the components on the motherboard.

[0042] A computing device is an electronic device used to perform computing tasks. Computing devices may include personal computers, servers, embedded computers, and supercomputers. This application uses a server as an example for illustrative purposes. The server in this application may be an independent physical server, or a server cluster or distributed system consisting of multiple physical servers. It may also be a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, cloud communications, middleware services, domain name services, security services, content delivery networks (CDNs), and large databases and artificial intelligence platforms. When the above-mentioned server is a server cluster or distributed system consisting of multiple physical servers, multiple physical servers can form a blockchain, and each physical server is a node on the blockchain. The physical types of servers may include cabinet servers, rack servers, high-density servers, graphics processing unit (GPU) servers, tower servers, blade servers, artificial intelligence (AI) servers, etc. The embodiments of this application do not limit the type of server.

[0043] Figure 1A This is a schematic diagram of the main circuit structure of a Buck circuit provided in an embodiment of the present application. Figure 1A As shown, the main circuit of the Buck circuit may include a high-side transistor Q1, a low-side transistor Q2, an inductor L, an input capacitor Cin, a node SW1, a first output capacitor Cout1, and a second output capacitor Cout2. Q1 and Q2 are both n-channel metal-oxide-semiconductor field-effect transistors (NMOS) and include a gate (G), a drain (D), and a source (S). Q1's D is coupled to the Buck circuit's positive voltage input terminal, and Q1's S is coupled to node SW1; Q2's S is grounded, and Q2's D is coupled to node SW1. Both Q1's G and Q2's G are coupled to the Buck circuit's driver circuit; one end of L is coupled to node SW1, and the other end of L is coupled to the Buck circuit's positive voltage output terminal; Cin is connected between the Buck circuit's positive voltage input terminal and ground; and Cout1 and Cout2 are connected in parallel between the Buck circuit's positive voltage output terminal and ground.

[0044] Figure 1B This is a schematic diagram of the main circuit structure of another Buck circuit provided in an embodiment of the present application. Figure 1B As shown, the main circuit of the Buck circuit is Figure 1A The main circuit structure of the Buck circuit shown is similar, the only difference is Figure 1B In the main circuit of the Buck circuit shown in FIG, a slow-start circuit 101 is connected in series between the positive voltage input terminal of the Buck circuit and D of Q1. Figure 1B As shown, the slow-start circuit 101 may include a slow-start switch Q3, wherein Q3 is an NMOS, a D terminal of Q3 is coupled to the positive voltage input terminal of the Buck circuit, an S terminal of Q3 is coupled to the D terminal of Q1, and a G terminal of Q3 is coupled to the driving circuit of the Buck circuit.

[0045] like Figure 1A or Figure 1B As shown in the figure, when Q1 short-circuits, the input voltage Vin of the buck circuit will flow directly through to the voltage output terminal, causing the output voltage Vout to overvoltage, thereby posing an input overvoltage risk to critical downstream loads. If no protective measures are taken, the input overvoltage of critical loads may directly cause them to fail. If a TVS diode is installed between the positive voltage output terminal of the buck circuit and ground, the TVS may not completely break down and enter a low-impedance state, causing the risk of sustained high temperatures and burning the PCB, resulting in low reliability and high cost.

[0046] Based on the above technical problems, an embodiment of the present application provides an output overvoltage protection circuit for a Buck circuit. The output overvoltage protection circuit of the Buck circuit may include a detection circuit and a controller. The detection circuit monitors the target voltage signal of the Buck circuit in real time and transmits the target voltage signal to the controller. The controller determines the switching state of a first switch tube based on the target voltage signal. When it is determined that the first switch tube is short-circuited and the short circuit lasts for a duration greater than or equal to a preset duration, that is, when it is determined that the first switch tube is continuously short-circuited, the controller controls the second switch tube to conduct, so that the first switch tube and the second switch tube form a direct path to clamp the output voltage of the Buck circuit. In this way, the risk of the input voltage of the Buck circuit directly passing through the output terminal is completely eliminated. By reusing the second switch tube instead of the TVS device, the circuit cost can be reduced, while avoiding the risk of continuous high temperature burning of the PCB caused by incomplete breakdown of the TVS into a low-resistance state, improving reliability, and thus achieving effective protection for important back-end loads.

[0047] The output overvoltage protection circuit of the Buck circuit provided in the embodiment of the present application can be used for Figure 1A Or the output voltage of the Buck circuit shown in 1B is overvoltage protected. The Buck circuit described in the embodiment of the present application is to more clearly illustrate the technical solution of the embodiment of the present application and does not constitute a limitation of the technical solution provided by the embodiment of the present application. Those skilled in the art will appreciate that as the system architecture evolves, the technical solution provided by the embodiment of the present application is equally applicable to similar technical problems.

[0048] Figure 2The output overvoltage protection circuit 20 of the Buck circuit can be used to protect the output overvoltage protection circuit 20 of the Buck circuit. Figure 1A Or the output voltage of the Buck circuit shown in 1B. Figure 1A or Figure 1B As shown, the Buck circuit may include a first switch tube Q1, a second switch tube Q2, a first common node SW2 (corresponding to Figure 1A or Figure 1B The inductor L is coupled between the first common node SW2 and the voltage output terminal of the Buck circuit. The first switch tube Q1 is coupled between the voltage input terminal of the Buck circuit and the first common node SW2; the second switch tube Q2 is coupled between the first common node SW2 and the ground GND. Figure 1A Take the Buck circuit shown in the figure as an example. Figure 2 As shown, the output overvoltage protection circuit 20 of the Buck circuit may include a detection circuit 201 and a controller 202 .

[0049] The detection circuit 201 is coupled to the Buck circuit and the controller 202 to obtain the target voltage signal of the Buck circuit and transmit the target voltage signal to the controller 202;

[0050] The controller 202 is configured to determine the switching state of the first switch Q1 based on the target voltage signal; and when it is determined that the first switch Q1 is continuously short-circuited, the controller 202 controls the second switch Q2 to be turned on, so that the first switch Q1 and the second switch Q2 form a through path to clamp the output voltage of the Buck circuit.

[0051] When the first switch tube Q1 is short-circuited and the duration of the short-circuit is greater than or equal to the preset duration, it is determined that the first switch tube Q1 is continuously short-circuited.

[0052] For example, the target voltage signal may be a voltage signal that can reflect the switching state of the first switch tube Q1 and may include one or more voltage signals.

[0053] In some examples, if Q1 is short-circuited, the voltage signal on the first common node SW2 is the same as the input voltage of the Buck circuit (both are logic high), regardless of whether the Buck circuit is operating in the on-state or the freewheeling state. That is, the switching state of Q1 is related to the voltage signal on the first common node SW2. In this case, the target voltage signal may include the first voltage detection signal sig_1 that can reflect the voltage signal on the first common node SW2.

[0054] In other examples, when the voltage signal on the control terminal (G) of Q2 is a logic high level (corresponding to Q2 being an NMOS tube), when the Buck circuit operates in the freewheeling stage, if Q1 is short-circuited, the voltage on the first common node SW2 will be greater than the on-state voltage drop of Q1, that is, the switching state of Q1 is simultaneously related to the voltage signal on the control terminal (G) of Q2 and the voltage signal on the first common node SW2. At this time, the target voltage signal may include a first voltage detection signal sig_1 that can reflect the voltage on the first common node SW2 and a second voltage detection signal sig_2 that can reflect the voltage on the control terminal of Q2.

[0055] In yet other examples, if Q1 is short-circuited, the voltage at the Buck circuit voltage output terminal is the same as the Buck circuit input voltage (both are logic high), regardless of whether the Buck circuit is operating in the on-state or the freewheeling state. That is, the switching state of Q1 is related to the voltage signal at the Buck circuit voltage output terminal. In this case, the target voltage signal may include a third voltage detection signal sig_3 that can reflect the voltage at the Buck circuit voltage output terminal. The present embodiment does not limit the type of target voltage.

[0056] The detection circuit 201 may be a circuit for detecting a target voltage signal, and different target voltage signals may correspond to different detection circuits 201. For example, if the target voltage signal includes a first voltage detection signal sig_1, the detection circuit 201 may include a first voltage divider circuit corresponding to the voltage signal on the first common node SW2. If the target voltage signal includes a first voltage detection signal sig_1 and a second voltage detection signal sig_2, the detection circuit 201 may include a first voltage divider circuit corresponding to the voltage signal on the first common node SW2 and a second voltage divider circuit corresponding to the voltage signal on the control terminal of Q2. If the target voltage signal includes a third voltage detection signal sig_3, the detection circuit 201 may include a third voltage divider circuit corresponding to the voltage signal on the voltage output terminal of the Buck circuit. The embodiment of the present application does not limit the structure of the detection circuit 201.

[0057] The controller 202 can be a control circuit for controlling the upper and / or lower tubes in the Buck circuit to implement overvoltage protection for the Buck circuit output. The controller 202 can be a microcontroller unit (MCU), a microprocessor unit (MPU), a digital signal processor (DSP), a field-programmable gate array (FPGA), and a system on chip (SoC). It can also be other types of control circuits. The embodiments of the present application do not limit the type of controller 202.

[0058] In some examples, the controller 202 may be a controller for a Buck circuit (implemented by adding the functionality of a Buck circuit controller) or a control circuit provided outside the Buck circuit. The embodiments of the present application do not limit the specific implementation of the controller 202. The embodiments of the present application are described illustratively using the example of the controller 202 being a Buck circuit controller.

[0059] It is understood that the switching state of the first switch Q1 may include off, on, short-circuited, and continuously short-circuited. A continuously short-circuited state of the first switch Q1 may be a state in which the first switch Q1 is short-circuited and the short-circuit duration is greater than or equal to a preset duration. In some examples, the controller 202 may determine that the first switch Q1 is short-circuited based on the target voltage signal, and determine that the first switch Q1 is continuously short-circuited when the short-circuit duration is greater than or equal to the preset duration.

[0060] Exemplarily, the preset time length is related to the response speed requirement of the Buck circuit. The higher the response speed requirement of the Buck circuit, the smaller the preset time length, and vice versa. In some examples, the preset time length may be greater than or equal to 1.5 times the switching period of the Buck circuit. For example, if the switching period of the Buck circuit is 10μs (microseconds), the preset time length may be greater than or equal to 15μs. The embodiment of the present application does not limit the size of the preset time length. The embodiment of the present application takes the switching period of the Buck circuit as 10μs and the preset time length as 15μs as an example for illustrative explanation. It can be determined according to the response speed requirement of the Buck circuit.

[0061] refer to Figure 1AAs shown, the controller 202 can determine the switching state of the first switch tube Q1 based on the target voltage signal; and when it is determined that the first switch tube Q1 is continuously short-circuited, it generates and sends a conduction control signal to the drive circuit of the second switch tube Q2. The drive circuit of the second switch tube Q2 can convert the conduction control signal into a drive signal suitable for driving the second switch tube, and send the drive signal to G of the second switch tube Q2, so that the second switch tube Q2 can turn on D and S in response to the drive signal, so that the first switch tube Q1 and the second switch tube Q2 form a through path to clamp the output voltage of the Buck circuit.

[0062] It is understood that when the first switch Q1 and the second switch Q2 form a direct path, the input voltage path impedance is extremely low. Therefore, the inductor L is bypassed, and the energy that would have been freewheeling through the inductor L is discharged through this direct path, clamping the output voltage of the Buck circuit to approximately 0V. Simultaneously, when the first switch Q1 and the second switch Q2 form a direct path, the input power supply Vin is short-circuited, thereby protecting the load. During the short-circuit period, the output voltage of the Buck circuit is clamped to 0V. This can be achieved by disconnecting the input power supply, for example, by opening a fuse, thus removing the input power from the Buck circuit. However, during the short-circuit period, a short-circuit current of tens or even hundreds of amperes will flow through the second switch Q2. This can cause a sharp rise in the junction temperature of the second switch Q2, parasitic conduction, and metal layer meltdown. Therefore, the input power supply must be disconnected promptly during this period to prevent the second switch Q2 from burning out, causing the input power to be directly applied to the load.

[0063] The output overvoltage protection circuit for a buck circuit provided in an embodiment of the present application utilizes a controller that, upon determining that the first switch is continuously short-circuited, controls the second switch to conduct, creating a direct path for the input power supply. This clamps the buck circuit's output voltage, completely eliminating the risk of the buck circuit's input voltage passing directly through to the output. Furthermore, by reusing the second switch in place of a TVS device, circuit costs are reduced while also avoiding the risk of the TVS incompletely breaking down and entering a low-resistance state, which could cause persistent high temperatures and damage the PCB. This improves reliability and effectively protects critical downstream loads.

[0064] In some embodiments of the present application, Figure 1A As shown, for a Buck circuit without a soft-start circuit, in order to improve the response speed of the output overvoltage protection circuit, the controller 202 may control the second switch tube Q2 to turn on when it is determined that the first switch tube Q1 is short-circuited before determining that the first switch tube Q1 is continuously short-circuited, so that the first switch tube Q1 and the second switch tube Q2 form a straight-through path to clamp the output voltage of the Buck circuit.

[0065] In other embodiments of the present application, Figure 1B As shown, for a Buck circuit equipped with a soft-start circuit 101, the controller 202 may first turn off the soft-start circuit 101 when determining that the first switch tube Q1 is short-circuited before determining that the first switch tube Q1 is continuously short-circuited, and control the second switch tube Q2 to be turned on only when the first switch tube Q1 is continuously short-circuited, so that the first switch tube Q1 and the second switch tube Q2 form a straight-through path to clamp the output voltage of the Buck circuit.

[0066] like Figure 3 As shown, in Figure 2 Based on the illustrated embodiment, the Buck circuit further includes a soft-start circuit 101 coupled between the voltage input terminal of the Buck circuit and the first switch tube Q1; a controller 202, coupled to the soft-start circuit 101, is configured to generate and send a shutdown signal to the soft-start circuit 101 when it is determined that a short circuit occurs in the first switch tube Q1; the soft-start circuit 101 is configured to disconnect the voltage input terminal of the Buck circuit from the first switch tube Q1 in response to the shutdown signal, thereby cutting off the input voltage of the Buck circuit.

[0067] For example, the shutdown signal can be at a first level or a second level, and can be determined based on the type of the slow-start switch Q3 in the slow-start circuit 101. If Q3 is an NMOS transistor, the shutdown signal is at the first level; if Q3 is a p-channel metal-oxide-semiconductor field-effect transistor (PMOS), the shutdown signal is at the second level.

[0068] In some examples, Q3 in the slow-start circuit 101 may receive a shutdown signal and disconnect D and S of Q3 in response to the shutdown signal, thereby disconnecting the voltage input terminal of the Buck circuit and D of Q1 and cutting off the input voltage Vin of the Buck circuit.

[0069] The output overvoltage protection circuit for a buck circuit provided in an embodiment of the present application includes a soft-start circuit. When the controller determines that a short circuit has occurred in the first switching transistor, it first controls the soft-start circuit to shut down, thereby cutting off the input voltage. If this input voltage cutoff scheme fails to clamp the buck circuit's output voltage in a timely manner, that is, if the first switching transistor remains short-circuited, the controller controls the second switching transistor to conduct, thereby forming a direct path for the input power. This not only eliminates the risk of sustained overvoltage at the source, but also minimizes damage to the second switching transistor while clamping the buck circuit's output voltage.

[0070] In some embodiments of the present application, when the Buck circuit is in the on-state, the voltage at the first common node SW2 is the same as the Buck circuit's input voltage Vin, i.e., the voltage signal at the first common node SW2 is at the second level. Based on this characteristic, the detection circuit 201 can detect a first voltage detection signal sig_1 that can reflect the voltage signal at the first common node SW2 and transmit the obtained first voltage detection signal sig_1 to the controller 202. In this way, the controller 202 can determine whether the first switch Q1 is short-circuited based on the first voltage detection signal sig_1.

[0071] In some examples, the target voltage detection signal may include a first voltage detection signal sig_1. Figure 1A Take the Buck circuit shown in the figure as an example to perform output overvoltage protection. Figure 4 As shown in the above Figure 2 Based on the illustrated embodiment, the detection circuit 201 may include a first voltage divider circuit 2011. The first voltage divider circuit 2011 is configured to detect the voltage at a first voltage dividing node a of the first voltage divider circuit 2011 and transmit the obtained first voltage detection signal sig_1 to the controller 202. The controller 202 is configured to determine the switching state of the first switching transistor based on the first voltage detection signal sig_1.

[0072] Continue to refer Figure 4 As shown, the first voltage divider circuit may include a first resistor R1, a second resistor R2, a third resistor R3, and a first capacitor C1. One end of the first resistor R1 is coupled to a first common node SW2, the other end of the first resistor R1 is coupled to one end of the second resistor R2, and the other end of the second resistor R2 is grounded GND. The connection point between the first resistor R1 and the second resistor R2 is a first voltage divider node a, which is also coupled to the controller 202. The third resistor R3 and the first capacitor C1 are coupled in parallel between the first voltage divider node a and ground GND.

[0073] In some examples, the third resistor R3 may be a pull-down resistor capable of stabilizing the voltage on the first voltage dividing node a, and the first capacitor C1 may be a high-frequency filter capacitor capable of removing high-frequency interference of the voltage on the first voltage dividing node a.

[0074] Because the first resistor R1 and the second resistor R2 are connected in series between the first common node SW2 and the ground GND, the voltage at the first voltage-dividing node a between the first resistor R1 and the second resistor R2 can reflect the voltage at the first common node SW2. Therefore, the controller 202 can monitor the voltage at the first common node SW2 by monitoring the voltage at the first voltage-dividing node a.

[0075] In the output overvoltage protection circuit of the Buck circuit provided in an embodiment of the present application, when the voltage on the first voltage-dividing node in the first voltage-dividing circuit can accurately reflect the conduction state of the first switching tube, the first voltage-dividing circuit detects the voltage on the first voltage-dividing node and transmits the obtained first voltage detection signal to the controller, so that the controller can accurately determine whether the switching state of the first switching tube is an abnormal short circuit based on the first voltage detection signal.

[0076] Continue to refer Figure 3 or Figure 4 As shown, the controller 202 can be specifically used to determine the voltage signal on the first common node based on the first voltage detection signal; when the voltage signal on the first common node SW2 is converted from a first level to a second level, and the duration of the second level is greater than or equal to the first duration, it is determined that the first switch tube is short-circuited; when the voltage signal on the first common node SW2 continues to be at the second level for a duration greater than or equal to a second duration, it is determined that the first switch tube is continuously short-circuited; wherein, the second duration is greater than the first duration.

[0077] In some examples, the relationship between the voltage signal Vsw on the first common node SW2 and the voltage signal Va on the first voltage-dividing node a can be shown in the following formula (1).

[0078] Vsw=[(R1+R2) / R2]*Va (1);

[0079] The controller 202 may determine the voltage signal Vsw on the first common node SW2 according to the voltage Va on the first voltage-dividing node a and formula (1).

[0080] The first duration can be the length of time it takes to determine if a short circuit has occurred in the first switch Q1. In some examples, the first duration can be related to the switching period (or switching frequency) of the first switch Q1, the overvoltage withstand capability of the buck circuit, and the capacitance. For example, if the switching frequency of the first switch Q1 is constant, the first duration can be longer if the overvoltage withstand capability and capacitance of the buck circuit are greater, and shorter if the overvoltage withstand capability and capacitance of the buck circuit are smaller.

[0081] Taking the switching period of the first switch Q1 as 10 μs as an example, the first duration may be greater than 10 μs or less than or equal to 10 μs. The embodiment of the present application does not limit the size of the first duration, and the embodiment of the present application takes the first duration of 10 μs as an example for illustrative description.

[0082] The second duration may correspond to the preset duration, and the embodiments of the present application will not be described in detail here.

[0083] For example, the first level may be a logic low level “0”, corresponding to the voltage of the ground GND; the second level may be a logic high level “1”, corresponding to the voltage of the positive input terminal of the Buck circuit.

[0084] It can be understood that when the voltage signal on the first common node SW2 transitions from the first level to the second level, it can be determined that the first switch Q1 transitions from the off state to the on state. If the voltage signal on the first common node SW2 remains at the second level for a duration greater than or equal to the switching period of the first switch Q1, that is, if the on-time of the first switch Q1 is greater than the switching period of the first switch Q1, it can be determined that the first switch Q1 is short-circuited. Furthermore, if the target voltage signal remains at the second level for a duration greater than or equal to the second duration, it can be determined that the first switch Q1 is continuously short-circuited.

[0085] In the output overvoltage protection circuit of the Buck circuit provided in an embodiment of the present application, when the voltage signal on the first common node is at a first level, indicating that the first switch is off, and when the voltage signal on the first common node is at a second level, indicating that the first switch is on, and when the first duration is greater than or equal to the duty cycle of the first switch, the controller can accurately determine that the first switch is short-circuited if the voltage signal on the first common node transitions from the first level to the second level, and the duration of the second level is greater than or equal to the first duration. When the duration of the second level is greater than or equal to the second duration, and the second duration is greater than the first duration, the controller can accurately determine that the first switch is continuously short-circuited.

[0086] Because of Figure 1B When the Buck circuit shown in FIG. 1 performs output overvoltage protection, the implementation method of determining whether the first switch tube Q1 is short-circuited or continuously short-circuited based on the first detection signal sig_1 is the same as that of FIG. Figure 1A When the Buck circuit shown performs output overvoltage protection, the implementation method of determining whether the first switch tube Q1 is short-circuited or continuously short-circuited based on the first detection signal sig_1 is similar, and the embodiment of the present application will not be repeated here.

[0087] In some embodiments of the present application, when the Buck circuit is in the freewheeling phase, the first switch Q1 should be in a normally off state, not short-circuited, and the second switch Q2 should be in the on state. At this point, the voltage at the first common node SW2 should theoretically be the conduction voltage drop of the second switch Q2. Based on this characteristic, it is possible to determine whether the first switch Q1 is short-circuited by obtaining the voltage signal at the control terminal of the second switch Q2 and the voltage signal at the first common node SW2.

[0088] In some examples, the target voltage signal may include a first voltage detection signal sig_1 and a second voltage detection signal sig_2. Figure 1A Take the Buck circuit shown in the figure as an example to perform output overvoltage protection. Figure 5 As shown in the above Figure 2 Based on the illustrated embodiment, the detection circuit 201 may include a first voltage divider circuit 2011 corresponding to the first voltage detection signal sig_1 and a second voltage divider circuit 2012 corresponding to the second voltage detection signal sig_2. The first voltage divider circuit 2011 is configured to monitor the voltage at a first voltage-dividing node a in the first voltage divider circuit 2011 in real time and transmit the resulting first voltage detection signal sig_1 to the controller 202. The second voltage divider circuit 2012 is configured to monitor the voltage at a second voltage-dividing node b in the second voltage divider circuit 2012 in real time and transmit the resulting second voltage detection signal sig_2 to the controller 202. The controller 202 is configured to determine the switching state of the first switch Q1 based on the first voltage detection signal sig_1 and the second voltage detection signal sig_2.

[0089] The structure of the first voltage divider circuit 2011 can be found in Figure 4 The embodiment shown in the figure is not described in detail here. Figure 5 As shown, the second voltage divider circuit 2012 may include a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a second capacitor C2. One end of the fourth resistor R4 is coupled to the control terminal (G) of the second switch Q2, the other end of the fourth resistor R4 is coupled to one end of the fifth resistor R5, and the other end of the fifth resistor R5 is grounded GND. The connection point between the fourth resistor R4 and the fifth resistor R5 is a second voltage divider node b, which is also coupled to the controller 202. The sixth resistor R6 and the second capacitor C2 are coupled in parallel between the second common node and ground GND.

[0090] Since the functions of the components in the second voltage divider circuit 2012 are similar to those of the corresponding components in the first voltage divider circuit 2011 , the functions of the components in the second voltage divider circuit 2012 are not further described in detail in the embodiment of the present application.

[0091] Similarly, because the fourth resistor R4 and the second resistor R5 are connected in series between the control terminal (G) of the second switch Q2 and ground GND, the voltage at the second voltage-dividing node b between the fourth resistor R4 and the second resistor R5 can reflect the voltage at the control terminal (G) of the second switch Q2. Therefore, the controller 202 can monitor the voltage at the control terminal (G) of the second switch Q2 by monitoring the voltage at the second voltage-dividing node d.

[0092] In the output overvoltage protection circuit of the Buck circuit provided in the embodiment of the present application, when the voltage on the first voltage-dividing node in the first voltage-dividing circuit can accurately reflect the conduction state of the first switching tube, and the voltage on the second voltage-dividing node in the second voltage-dividing circuit can accurately reflect the conduction state of the second switching tube, the first voltage-dividing circuit detects the voltage on the first voltage-dividing node and transmits the obtained first voltage detection signal to the controller, and the second voltage-dividing circuit detects the voltage on the second voltage-dividing node and transmits the obtained second voltage detection signal to the controller, the controller can accurately determine whether the switch state of the first switching tube is an abnormal short circuit based on the first voltage detection signal and the second voltage detection signal.

[0093] Continue to refer Figure 5 As shown, the controller 202 can be used to determine the voltage signal on the first common node SW2 based on the first voltage detection signal sig_1; determine the voltage signal on the control end of the second switch tube Q2 based on the second voltage detection signal sig_2; when the voltage signal on the control end of the second switch tube Q2 is a second level and the amplitude of the voltage signal on the first common node SW2 is greater than the first voltage threshold, determine that the first switch tube Q1 is short-circuited; when the voltage signal on the control end of the second switch tube Q2 is a second level and the amplitude of the voltage signal on the first common node SW2 is greater than the second voltage threshold, determine that the first switch tube Q1 is continuously short-circuited; wherein the second voltage threshold is greater than the first voltage threshold.

[0094] For example, the first voltage threshold may be the voltage at the first common node SW2 when the Buck circuit is operating in the freewheeling phase and the first switch Q1 is in the normally off state. In some examples, the first voltage threshold may be the on-state voltage drop of the second switch Q2. For example, if the operating current of the second switch Q2 is 10A (amperes) and the on-state resistance is 10mΩ (milliohms), the first voltage threshold may be 0.1V (volts).

[0095] The second voltage threshold can be any voltage value greater than the first voltage threshold and can be determined based on the response speed requirement of the Buck circuit. In some examples, the higher the response speed requirement of the Buck circuit, the smaller the second voltage threshold, and vice versa. For example, when the first voltage threshold is 0.1V, the second voltage threshold can be 0.5V. The embodiment of the present application does not limit the specific size of the second voltage threshold. The embodiment of the present application uses the second voltage threshold of 0.5V as an example for illustrative description.

[0096] For example, if the second switch Q2 is an NMOS transistor and the second level is a logic high level "1," when the voltage signal at the control terminal of the second switch Q2 is at the second level (i.e., the control terminal of the second switch Q2 is at a logic high level "1") and the second switch Q2 is turned on to freewheel the inductor L, if the amplitude of the voltage signal at the first common node SW2 (the voltage at the first common node SW2) is greater than or equal to the forward voltage drop of the second switch Q2, it can be determined that the first switch Q1 has a short circuit. Furthermore, when the second voltage threshold is greater than the forward voltage drop of the second switch Q2, it can be further determined that the first switch Q1 has a sustained short circuit.

[0097] The output overvoltage protection circuit of the Buck circuit provided in the embodiment of the present application is such that when the voltage signal on the control terminal of the second switch tube is at the second level, the second switch tube is turned on, the Buck circuit operates in the freewheeling stage, and the current of the second switch tube flows from the source S to the drain D. At this time, the voltage of SW1 is equal to the on-state voltage drop (negative value) of the second switch tube. Therefore, when the Buck circuit operates normally in the freewheeling stage, the voltage signal on the first common node must be equal to the on-state voltage drop of the second switch tube. Therefore, when the first voltage threshold corresponds to the on-state voltage drop of the second switch tube, the controller can accurately determine that the first switch tube is short-circuited when the voltage signal on the control terminal of the second switch tube is at the second level and the amplitude of the voltage signal on the first common node is greater than the first voltage threshold. When the voltage signal on the control terminal of the second switch tube is at the second level, the amplitude of the voltage signal on the first common node is greater than the second voltage threshold, and the second voltage threshold is greater than the first voltage threshold, it is accurately determined that the first switch tube is continuously short-circuited.

[0098] Because of Figure 1B When the Buck circuit shown in FIG. 1 performs output overvoltage protection, the implementation method of determining whether the first switch tube Q1 is short-circuited and continuously short-circuited based on the first detection signal sig_1 and the second detection signal sig_2 is the same as that of FIG. Figure 1A When the Buck circuit shown performs output overvoltage protection, the implementation method of determining whether the first switch tube Q1 is short-circuited and continuously short-circuited based on the first detection signal sig_1 and the second detection signal sig_2 is similar, and the embodiments of the present application will not be repeated here.

[0099] In some embodiments of the present application, during normal operation of the Buck circuit, the output voltage Vout is a preset voltage lower than the input voltage Vin. If the first switch Q1 short-circuits, the output voltage Vout will abnormally increase. Based on this characteristic, the output voltage Vout of the Buck circuit can be obtained and, based on the output voltage Vout of the Buck circuit, whether the first switch Q1 is short-circuited can be determined.

[0100] In some examples, the target voltage signal may include a third voltage detection signal sig_3. Figure 1A Take the Buck circuit shown in the figure as an example to perform output overvoltage protection. Figure 6 As shown, in Figure 2 Based on the illustrated embodiment, the detection circuit 201 may include a third voltage divider circuit 2013. The third voltage divider circuit 2013 is configured to monitor the voltage at a third voltage dividing node c in the third voltage divider circuit 2013 in real time and transmit the obtained third voltage detection signal sig_3 to the controller 202. The controller 202 is configured to determine the switching state of the first switch Q1 based on the third voltage detection signal sig_3.

[0101] Continue to refer Figure 6 As shown, the third voltage divider circuit 2013 may include a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a third capacitor C3. One end of the seventh resistor R7 is coupled to the voltage output terminal of the Buck circuit, the other end of the seventh resistor R7 is coupled to one end of the eighth resistor R8, and the other end of the eighth resistor R8 is grounded GND. The connection point between the seventh resistor R7 and the eighth resistor R8 is a third voltage divider node c, which is also coupled to the controller 202. The ninth resistor R9 and the third capacitor C3 are coupled in parallel between the third voltage divider node c and ground GND.

[0102] Since the structure of the third voltage divider circuit 2013 is similar to that of the first voltage divider circuit 2011 and the second voltage divider circuit 2012 , the structure of the third voltage divider circuit 2013 is not further described in the embodiment of the present application.

[0103] Similarly, because the seventh resistor R7 and the eighth resistor R8 are connected in series between the voltage output terminal of the Buck circuit and ground GND, the voltage at the third voltage-dividing node c between the seventh resistor R7 and the eighth resistor R8 can reflect the voltage at the voltage output terminal of the Buck circuit. Therefore, the controller 202 can monitor the voltage at the voltage output terminal of the Buck circuit by monitoring the voltage at the third voltage-dividing node c.

[0104] In the output overvoltage protection circuit of the Buck circuit provided in the embodiment of the present application, when the voltage on the third voltage-dividing node in the third voltage-dividing circuit can accurately reflect the conduction state of the first switching tube, the third voltage-dividing circuit detects the voltage on the third voltage-dividing node and transmits the obtained third voltage detection signal to the controller, so that the controller can accurately determine whether the switching state of the first switching tube is an abnormal short circuit based on the third voltage detection signal.

[0105] Continue to refer Figure 6As shown, the controller 202 is used to determine the voltage signal at the voltage output end of the Buck circuit based on the third voltage detection signal sig_3; when the voltage signal at the voltage output end of the Buck circuit is greater than the third voltage threshold, it is determined that the first switch tube is short-circuited; when the voltage signal at the voltage output end of the Buck circuit is greater than the fourth voltage threshold, it is determined that the first switch tube is continuously short-circuited; wherein the fourth voltage threshold is greater than the third voltage threshold.

[0106] The third voltage threshold can be the maximum voltage that a critical load at the back end of the Buck circuit can withstand, and can be determined based on the load's withstand voltage and the Buck circuit's output voltage during normal operation. In some examples, if the Buck circuit's output voltage during normal operation is 1 to 1.2V and the load's withstand voltage is 1.5V, the third voltage threshold can be determined to be 1.3V.

[0107] The fourth voltage threshold may be any voltage value greater than the third voltage threshold and may be determined based on the response speed requirement of the Buck circuit. In some examples, the higher the response speed requirement of the Buck circuit, the smaller the fourth voltage threshold, and vice versa. For example, when the third voltage threshold is 1.3V, the fourth voltage threshold may be 1.4V. The embodiments of the present application do not limit the specific value of the fourth voltage threshold. The embodiments of the present application use the fourth voltage threshold of 1.4V as an example for illustrative description.

[0108] In the output overvoltage protection circuit of a Buck circuit provided in an embodiment of the present application, when the third voltage threshold reflects the maximum voltage that an important load at the back end of the Buck circuit can withstand, the controller can accurately determine that a short circuit has occurred in the first switch tube when the amplitude of the third voltage detection signal is greater than the third voltage threshold. Furthermore, when the amplitude of the third voltage detection signal is greater than a fourth voltage threshold, and the fourth voltage threshold is greater than the third voltage threshold, the controller can accurately determine that a short circuit has persisted in the first switch tube.

[0109] Because of Figure 1B When the Buck circuit shown in FIG. 1 performs output overvoltage protection, the implementation method of determining whether the first switch tube Q1 is short-circuited and continuously short-circuited based on the third detection signal sig_3 is the same as that of FIG. Figure 1A When the Buck circuit shown performs output overvoltage protection, the implementation method of determining whether the first switch tube Q1 is short-circuited and continuously short-circuited based on the third detection signal sig_3 is similar, and the embodiment of the present application will not be repeated here.

[0110] Corresponding to the embodiment of the output overvoltage protection circuit of the Buck circuit described above, the present application also provides an output overvoltage protection method of the Buck circuit, which is applied to Figure 2 Controller 202 in the circuit shown. Figure 7This is a flow chart of an output overvoltage protection method for a Buck circuit provided in an embodiment of the present application. Figure 7 As shown, the output overvoltage protection method of the Buck circuit may include the following steps S701 to S703.

[0111] Step S701: Acquire a target voltage signal of the Buck circuit.

[0112] Step S702: Determine the switching state of the first switch tube based on the target voltage signal.

[0113] Step S703: When it is determined that the first switch is continuously short-circuited, the second switch is controlled to conduct, so that the first and second switches form a direct path to clamp the output voltage of the Buck circuit. The first switch is determined to be continuously short-circuited when the short circuit lasts for a duration greater than or equal to a predetermined duration.

[0114] In some embodiments, the output overvoltage protection method of the Buck circuit also includes: when it is determined that the first switch tube is short-circuited, generating and sending a shutdown signal to the soft-start circuit, disconnecting the connection between the voltage input terminal of the Buck circuit and the first switch tube to cut off the input voltage of the Buck circuit.

[0115] In some embodiments, the target voltage signal includes a first voltage detection signal, and determining the switching state of the first switch tube based on the target voltage signal may include: determining the switching state of the first switch tube based on the first voltage detection signal.

[0116] In some embodiments, determining the switching state of the first switching tube based on the first voltage detection signal may include: determining the voltage signal on the first common node based on the first voltage detection signal; determining that the first switching tube is short-circuited when the voltage signal on the first common node is converted from a first level to a second level, and the duration of the second level is greater than or equal to the first duration; determining that the first switching tube is continuously short-circuited when the voltage signal on the first common node continues at the second level for a duration greater than or equal to a second duration; wherein the second duration is greater than the first duration.

[0117] In some embodiments, determining the switching state of the first switch tube based on the target voltage signal may include: determining the switching state of the first switch tube based on the first voltage detection signal and the second voltage detection signal.

[0118] In some embodiments, determining the switching state of the first switching tube based on the first voltage detection signal and the second voltage detection signal may include: determining the voltage signal on the first common node based on the first voltage detection signal; determining the voltage signal on the control end of the second switching tube based on the second voltage detection signal; determining that the first switching tube is short-circuited when the voltage signal on the control end of the second switching tube is a second level and the amplitude of the voltage signal on the first common node is greater than the first voltage threshold; determining that the first switching tube is continuously short-circuited when the voltage signal on the control end of the second switching tube is a second level and the amplitude of the voltage signal on the first common node is greater than the second voltage threshold; wherein the second voltage threshold is greater than the first voltage threshold.

[0119] In some embodiments, the target voltage signal includes a third voltage detection signal, and determining the switching state of the first switch tube based on the target voltage signal may include: determining the switching state of the first switch tube based on the third voltage detection signal.

[0120] In some embodiments, determining the switching state of the first switching tube based on the third voltage detection signal may include: determining the voltage signal at the voltage output end of the Buck circuit based on the third voltage detection signal; determining that the first switching tube is short-circuited when the voltage signal at the voltage output end of the Buck circuit is greater than a third voltage threshold; determining that the first switching tube is continuously short-circuited when the voltage signal at the voltage output end of the Buck circuit is greater than a fourth voltage threshold; wherein the fourth voltage threshold is greater than the third voltage threshold.

[0121] The beneficial technical effects corresponding to the exemplary embodiment of the output overvoltage protection method of the Buck circuit mentioned above can be found in the corresponding beneficial technical effects of the above method embodiment part, which will not be repeated here.

[0122] Corresponding to the embodiment of the output overvoltage protection method of the Buck circuit described above, the embodiment of the present application also provides an embodiment of an output overvoltage protection device of the Buck circuit. Figure 8 As shown, the output overvoltage protection device 80 of the Buck circuit may include an acquisition module 801 , a first determination module 802 and a first control module 803 .

[0123] The acquisition module 801 is used to acquire the target voltage signal of the Buck circuit.

[0124] The first determining module 802 is configured to determine the switching state of the first switching tube based on the target voltage signal.

[0125] The first control module 803 is configured to control the second switch to conduct when the first switch is determined to be continuously short-circuited, so that the first and second switches form a direct path to clamp the output voltage of the Buck circuit. The first switch is determined to be continuously short-circuited when the short circuit lasts for a duration greater than or equal to a preset duration.

[0126] In some embodiments, the output overvoltage protection device 80 of the Buck circuit also includes: a second control module, which is used to generate and send a shutdown signal to the soft-start circuit when it is determined that the first switch tube is short-circuited, so as to disconnect the connection between the voltage input terminal of the Buck circuit and the first switch tube, thereby cutting off the input voltage of the Bcuk circuit.

[0127] In some embodiments, the target voltage signal includes a first voltage detection signal, and the first determination module 802 is specifically configured to determine the switching state of the first switch tube based on the first voltage detection signal.

[0128] In some embodiments, the first determination module 802 is specifically used to determine the voltage signal on the first common node based on the first voltage detection signal; when the voltage signal on the first common node is converted from a first level to a second level, and the duration of the second level is greater than or equal to the first duration, it is determined that the first switch tube is short-circuited; when the voltage signal on the first common node continues at the second level for a duration greater than or equal to a second duration, it is determined that the first switch tube is continuously short-circuited; wherein, the second duration is greater than the first duration.

[0129] In some embodiments, the target voltage signal includes a first voltage detection signal and a second voltage detection signal. The first determination module 802 is specifically configured to determine the switching state of the first switch tube based on the first voltage detection signal and the second voltage detection signal.

[0130] In some embodiments, the first determination module 802 is specifically used to determine the voltage signal on the first common node based on the first voltage detection signal; determine the voltage signal on the control end of the second switch tube based on the second voltage detection signal; when the voltage signal on the control end of the second switch tube is a second level and the amplitude of the voltage signal on the first common node is greater than the first voltage threshold, determine that the first switch tube is short-circuited; when the voltage signal on the control end of the second switch tube is a second level and the amplitude of the voltage signal on the first common node is greater than the second voltage threshold, determine that the first switch tube is continuously short-circuited; wherein, the second voltage threshold is greater than the first voltage threshold.

[0131] In some embodiments, the target voltage signal includes a third voltage detection signal, and the first determination module 802 is specifically configured to determine the switching state of the first switch tube based on the third voltage detection signal.

[0132] In some embodiments, the first determination module 802 is specifically used to determine the voltage signal at the voltage output end of the Buck circuit based on the third voltage detection signal; when the voltage signal at the voltage output end of the Buck circuit is greater than the third voltage threshold, it is determined that the first switch tube is short-circuited; when the voltage signal at the voltage output end of the Buck circuit is greater than the fourth voltage threshold, it is determined that the first switch tube is continuously short-circuited; wherein the fourth voltage threshold is greater than the third voltage threshold.

[0133] The beneficial technical effects corresponding to the exemplary embodiment of the output overvoltage protection device 80 of the Buck circuit can be found in the corresponding beneficial technical effects of the above method embodiment part, which will not be repeated here.

[0134] Corresponding to the embodiment of the output overvoltage protection circuit of the aforementioned Buck circuit, the present application also provides an embodiment of a computing device. Figure 9 This is a schematic diagram of the structure of a computing device provided in an embodiment of the present application. Figure 9 As shown, the computing device 90 includes a Buck circuit 901 and an output overvoltage protection circuit 902 of the aforementioned Buck circuit.

[0135] For example, the output overvoltage protection circuit 902 of the Buck circuit may correspond to Figure 2 The output overvoltage protection circuit 20 of the Buck circuit in the illustrated embodiment.

[0136] It should be noted that the beneficial technical effects corresponding to the exemplary embodiments of the above-mentioned computing device can be found in the corresponding beneficial technical effects of the above-mentioned circuit embodiment part, which will not be repeated here.

[0137] In addition, an embodiment of the present application may also be a computer-readable storage medium on which computer program instructions are stored. When the computer program instructions are executed by a processor, the processor executes the steps of the output overvoltage protection method of the Buck circuit of various embodiments of the present application described in the above method embodiment section.

[0138] Computer readable storage media can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium is, for example, but not limited to, a system, device or component comprising electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination thereof. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0139] The basic principles of the present application have been described above in conjunction with specific embodiments. However, the advantages, strengths, and effects mentioned in this application are merely illustrative and not restrictive, and should not be considered as necessarily possessed by each embodiment of this application. In addition, the specific details of the above embodiments are merely illustrative and for ease of understanding, and are not restrictive. The above details do not limit this application to necessarily being implemented using the above specific details.

[0140] Those skilled in the art may make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations.

[0141] Moreover, the above-described embodiments are only specific embodiments of the present application and are not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solutions of the present application shall be included in the scope of protection of the present application.

Claims

1. An output overvoltage protection circuit for a Buck circuit, characterized in that: The Buck circuit includes a first switching tube, a second switching tube, a first common node, and an inductor, wherein the inductor is coupled between the first common node and a voltage output terminal of the Buck circuit, and the first switching tube is coupled between a voltage input terminal of the Buck circuit and the first common node; The second switch tube is coupled between the first common node and the ground; The output overvoltage protection circuit comprises: a detection circuit, coupled to the Buck circuit and the controller, configured to obtain a target voltage signal of the Buck circuit and transmit the target voltage signal to the controller; The controller is configured to determine the switching state of the first switching tube based on the target voltage signal; and when it is determined that the first switching tube is continuously short-circuited, control the second switching tube to conduct, so that the first switching tube and the second switching tube form a through path to clamp the output voltage of the Buck circuit; wherein the first switching tube is determined to be continuously short-circuited when a short circuit occurs in the first switching tube and the duration of the short circuit is greater than or equal to a preset duration.

2. The circuit according to claim 1, wherein: The Buck circuit further includes a slow-start circuit coupled between the voltage input terminal of the Buck circuit and the first switch tube; The controller is coupled to the slow-start circuit and is further configured to generate and send a shutdown signal to the slow-start circuit when it is determined that the first switch tube is short-circuited; The soft-start circuit is configured to disconnect the voltage input terminal of the Buck circuit from the first switch tube in response to the shutdown signal, so as to cut off the input voltage of the Buck circuit.

3. The circuit according to claim 1 or 2, characterized in that The target voltage signal includes a first voltage detection signal; the detection circuit includes a first voltage divider circuit corresponding to the first voltage detection signal; The first voltage divider circuit is configured to detect a voltage on a first voltage dividing node in the first voltage divider circuit and transmit a first voltage detection signal obtained to the controller; The controller is configured to determine a switching state of the first switching tube based on the first voltage detection signal.

4. The circuit according to claim 3, characterized in that The controller is specifically configured to determine a voltage signal on the first common node based on the first voltage detection signal; and determine that a short circuit occurs in the first switch tube when the voltage signal on the first common node changes from a first level to a second level and the duration of the second level is greater than or equal to a first duration; When the duration of the voltage signal on the first common node remaining at the second level is greater than or equal to a second duration, it is determined that the first switch tube is continuously short-circuited; wherein the second duration is greater than the first duration.

5. The circuit according to claim 3, characterized in that The first voltage divider circuit includes a first resistor, a second resistor, a third resistor, and a first capacitor; one end of the first resistor is coupled to the first common node, the other end of the first resistor is coupled to one end of the second resistor, and the other end of the second resistor is grounded; the connection point between the first resistor and the second resistor is the first voltage divider node and is coupled to the controller; the third resistor and the first capacitor are connected in parallel between the first voltage divider node and ground.

6. The circuit according to claim 1 or 2, characterized in that The target voltage signal includes a first voltage detection signal and a second voltage detection signal; the detection circuit includes a first voltage divider circuit corresponding to the first voltage detection signal and a second voltage divider circuit corresponding to the second voltage detection signal; The first voltage divider circuit is configured to monitor the voltage on the first voltage divider node in the first voltage divider circuit in real time, and transmit the obtained first voltage detection signal to the controller; The second voltage-dividing circuit is configured to monitor the voltage on the second voltage-dividing node in the second voltage-dividing circuit in real time, and transmit the obtained second voltage detection signal to the controller; The controller is configured to determine a switching state of the first switching tube based on the first voltage detection signal and the second voltage detection signal.

7. The circuit according to claim 6, characterized in that The controller is configured to determine a voltage signal on the first common node based on the first voltage detection signal; and determine a voltage signal on the control terminal of the second switch tube based on the second voltage detection signal; When the voltage signal on the control terminal of the second switch tube is at a second level and the amplitude of the voltage signal on the first common node is greater than a first voltage threshold, it is determined that the first switch tube is short-circuited; When the voltage signal on the control end of the second switch tube is the second level and the amplitude of the voltage signal on the first common node is greater than a second voltage threshold, it is determined that the first switch tube is continuously short-circuited; wherein the second voltage threshold is greater than the first voltage threshold.

8. The circuit according to claim 1 or 2, characterized in that The target voltage signal includes a third voltage detection signal; the detection circuit includes a third voltage dividing circuit corresponding to the third voltage detection signal; The third voltage-dividing circuit is configured to monitor the voltage on the third voltage-dividing node in the third voltage-dividing circuit in real time, and transmit the obtained third voltage detection signal to the controller; The controller is configured to determine a switching state of the first switching tube based on the third voltage detection signal.

9. The circuit according to claim 8, characterized in that The controller is configured to determine a voltage signal at a voltage output terminal of the Buck circuit based on the third voltage detection signal; and determine that a short circuit occurs in the first switch tube when the voltage signal at the voltage output terminal of the Buck circuit is greater than a third voltage threshold; When the voltage signal at the voltage output end of the Buck circuit is greater than a fourth voltage threshold, it is determined that the first switch tube is continuously short-circuited; wherein the fourth voltage threshold is greater than the third voltage threshold.

10. A computing device, characterized in that The invention comprises a Buck circuit and an output overvoltage protection circuit of the Buck circuit according to any one of claims 1 to 9.

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