A protection circuit and a smart terminal

Abstract

This application discloses a protection circuit and a smart terminal. The protection circuit includes an overcurrent protection module electrically connected between the system power supply on the motherboard and a first load module. The overcurrent protection module disconnects the power supply path between the system power supply and the first load module when a short circuit occurs in the first load module. This isolates the associated power supply when the load module short-circuits due to water ingress or component failure, preventing malfunctions such as the device failing to power on or restart due to a short circuit in the load module.

Description

Technical Field

[0001] This application relates to the field of integrated circuit technology, specifically to a protection circuit and a smart terminal. Background Technology

[0002] With the widespread application of smart terminals, the complexity of their internal structures is constantly increasing. Existing smart terminals, such as mobile phones, typically consist of a motherboard and a sub-board. The motherboard integrates most of the phone's core components, such as the central processing unit, memory, system power supply, and power management module. The sub-board is usually responsible for connecting and managing the phone's peripheral devices, such as charging ports, headphone jacks, SIM card slots, speakers, microphones, and other load components. Due to the requirements of their operating principles, these components inevitably need to have openings around them. These openings directly increase the difficulty of waterproofing, making the sub-board prone to water ingress and short circuits during long-term use, causing the phone to fail to power on. In addition, drops and impacts during phone use, and high-temperature shocks during charging, often cause capacitors on the sub-board to fail, leading to problems such as the phone failing to power on or restarting, seriously affecting the user experience.

[0003] While some waterproofing measures exist in existing technologies, most rely on structural waterproofing, such as waterproof nano-coatings and waterproof shielding covers. However, structural waterproofing typically suffers from high costs, susceptibility to cracking, poor heat dissipation, and difficulty in repair. After a certain period of use, water ingress and short circuits on the phone's secondary circuit board or component failure and short circuits can still occur, leading to the phone failing to power on or restarting, thus affecting the phone's basic functions.

[0004] The preceding description is intended to provide general background information and does not necessarily constitute prior art. Utility Model Content

[0005] To address the aforementioned technical problems, this application provides a protection circuit and a smart terminal that can isolate the associated power supply when the load module is short-circuited due to water ingress or component failure, thereby preventing malfunctions such as the device failing to power on or restart due to a short circuit in the load module.

[0006] To solve the above-mentioned technical problems, this application provides a protection circuit, characterized in that the protection circuit is disposed on the motherboard of the smart terminal, the motherboard is also provided with a system power supply, and the protection circuit includes an overcurrent protection module;

[0007] The overcurrent protection module is electrically connected between the system power supply and the first load module, and is used to disconnect the power supply path between the system power supply and the first load module when a short circuit occurs in the first load module.

[0008] Optionally, the overcurrent protection module includes an overcurrent protection chip; the voltage input terminal of the overcurrent protection chip is electrically connected to the system power supply, the voltage output terminal of the overcurrent protection chip is electrically connected to the first load module, and the enable terminal and overcurrent flag output terminal of the overcurrent protection chip are both electrically connected to the control module on the motherboard.

[0009] Optionally, the overcurrent protection module further includes an external circuit electrically connected to the overcurrent protection chip; wherein the external circuit includes a pull-up resistor, one end of which is electrically connected to the overcurrent flag output terminal of the overcurrent protection chip, and the other end of which is electrically connected to a reference power supply.

[0010] Optionally, the peripheral circuit further includes a current limiting protection threshold resistor, which is electrically connected to the current setting terminal of the overcurrent protection chip and is used to set the current limiting threshold of the overcurrent protection chip.

[0011] Optionally, the peripheral circuit further includes an input voltage regulator and / or an output voltage regulator, wherein the input voltage regulator is electrically connected to the voltage input terminal of the overcurrent protection chip, and the output voltage regulator is electrically connected to the voltage output terminal of the overcurrent protection chip.

[0012] Optionally, the overcurrent protection chip includes a switching circuit, which includes a first field-effect transistor and a second field-effect transistor; the drain of the first field-effect transistor is electrically connected to the voltage input terminal of the overcurrent protection chip, and the source of the first field-effect transistor is electrically connected to the source of the second field-effect transistor; the drain of the second field-effect transistor is electrically connected to the voltage output terminal of the overcurrent protection chip.

[0013] Optionally, the protection circuit further includes a current limiting protection module; the current limiting protection module is electrically connected between the power management module and the second load module on the motherboard, and is used to limit the current flowing into the second load module when a short circuit occurs in the second load module.

[0014] Optionally, the current limiting protection module includes at least two current limiting resistors, one end of each current limiting resistor is electrically connected to the power management module, and the other end of each current limiting resistor is electrically connected to the corresponding load component in the second load module.

[0015] This application also provides a smart terminal, which includes a motherboard and a sub-board. The motherboard includes a system power supply, a control module, a power management module, and a protection circuit as described above. The sub-board includes a first load module and a second load module.

[0016] Optionally, the first load module is directly powered by the system power supply, and the second load module is powered by the corresponding power supply through the power management module.

[0017] As described above, the protection circuit and smart terminal provided in this application, through an overcurrent protection module electrically connected between the system power supply and the first load module on the motherboard, disconnect the power supply path between the system power supply and the first load module when a short circuit occurs in the first load module. In this way, when the load module short-circuits due to water ingress or component failure, the associated power supply can be isolated, preventing malfunctions such as the device failing to power on or restart due to a short circuit in the load module. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0019] Figure 1 A schematic diagram of the hardware structure of a smart terminal to implement the various embodiments of this application.

[0020] Figure 2 This is a communication network system architecture diagram provided for an embodiment of this application.

[0021] Figure 3 This is a circuit diagram of an overcurrent protection module provided in an embodiment of this application.

[0022] Figure 4 This is a schematic diagram of the internal structure of an overcurrent protection chip provided in an embodiment of this application.

[0023] Figure 5 This is a circuit diagram of a current limiting protection module provided in an embodiment of this application.

[0024] Figure 6 This is a structural block diagram of a smart terminal provided in an embodiment of this application.

[0025] The realization of the objectives, functional features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and textual descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0026] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0027] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, components, features, and elements with the same names in different embodiments of this application may have the same meaning or different meanings, the specific meaning of which must be determined by its interpretation in that specific embodiment or further in conjunction with the context of that specific embodiment.

[0028] It should be understood that although the terms first, second, third, etc., may be used herein to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this document, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if," as used herein, may be interpreted as "when," "when," or "in response to determination." Furthermore, as used herein, the singular forms "a," "an," and "the" are intended to also include the plural forms unless the context indicates otherwise. It should be further understood that the terms "comprising," "including," indicate the presence of the stated feature, step, operation, element, component, item, kind, and / or group, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, kinds, and / or groups. The terms "or," "and / or," "including at least one of the following," etc., as used in this application, may be interpreted as inclusive, or mean any one or any combination thereof. For example, "including at least one of the following: A, B, C" means "any one of the following: A; B; C; A and B; A and C; B and C; A and B and C." Similarly, "A, B, or C" or "A, B, and / or C" means "any one of the following: A; B; C; A and B; A and C; B and C; A and B and C." Exceptions to this definition only occur when the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way.

[0029] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0030] In the following description, the use of suffixes such as "module," "part," or "unit" to denote elements is solely for the purpose of illustrative purposes and has no specific meaning in itself. Therefore, "module," "part," or "unit" may be used interchangeably.

[0031] Smart terminals can be implemented in various forms. For example, the smart terminals described in this application may include smart terminals such as mobile phones, tablets, laptops, handheld computers, personal digital assistants (PDAs), portable media players (PMPs), navigation devices, wearable devices, smart bracelets, pedometers, etc., as well as fixed terminals such as digital TVs and desktop computers.

[0032] The following description will use a mobile terminal as an example. Those skilled in the art will understand that, apart from elements specifically designed for mobile purposes, the construction according to the embodiments of this application can also be applied to fixed-type terminals.

[0033] Please see Figure 1 This is a schematic diagram of the hardware structure of a mobile terminal implementing various embodiments of this application. The mobile terminal 100 may include: an RF (Radio Frequency) unit 101, a WiFi module 102, an audio output unit 103, an A / V (Audio / Video) input unit 104, a sensor 105, a display unit 106, a user input unit 107, an interface unit 108, a memory 109, a processor 110, and a power supply 111, etc. Those skilled in the art will understand that... Figure 1 The mobile terminal structure shown does not constitute a limitation on the mobile terminal. The mobile terminal may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0034] The following is combined with Figure 1 A detailed introduction to each component of the mobile terminal:

[0035] The radio frequency unit 101 can be used for receiving and transmitting signals during information transmission or calls. Specifically, it receives downlink information from the base station and processes it with the processor 110; additionally, it transmits uplink data to the base station. Typically, the radio frequency unit 101 includes, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a low-noise amplifier, and a duplexer. Furthermore, the radio frequency unit 101 can also communicate wirelessly with networks and other devices. The aforementioned wireless communications may use any communication standard or protocol, including but not limited to GSM (Global System of Mobile communication), GPRS (General Packet Radio Service), CDMA2000 (Code Division Multiple Access 2000), WCDMA (Wideband Code Division Multiple Access), TD-SCDMA (Time Division-Synchronous Code Division Multiple Access), FDD-LTE (Frequency Division Duplexing-Long Term Evolution), TDD-LTE (Time Division Duplexing-Long Term Evolution), and 5G, etc.

[0036] WiFi is a short-range wireless transmission technology. Mobile terminals, through the WiFi module 102, can help users send and receive emails, browse web pages, and access streaming media, providing users with wireless broadband internet access. Although Figure 1 WiFi module 102 is shown, but it is understood that it is not a necessary component of a mobile terminal and can be omitted as needed without changing the nature of the invention.

[0037] The audio output unit 103 can convert audio data received by the radio frequency unit 101 or the WiFi module 102 or stored in the memory 109 into audio signals and output them as sound when the mobile terminal 100 is in call signal receiving mode, call mode, recording mode, voice recognition mode, broadcast receiving mode, etc. Furthermore, the audio output unit 103 can also provide audio output related to specific functions performed by the mobile terminal 100 (e.g., call signal receiving sound, message receiving sound, etc.). The audio output unit 103 may include a speaker, a buzzer, etc.

[0038] The A / V input unit 104 is used to receive audio or video signals. The A / V input unit 104 may include a graphics processing unit (GPU) 1041 and a microphone 1042. The GPU 1041 processes image data of still images or videos acquired by an image capture device (such as a camera) in video capture mode or image capture mode. The processed image frames can be displayed on the display unit 106. The image frames processed by the GPU 1041 can be stored in the memory 109 (or other storage media) or transmitted via the radio frequency unit 101 or the WiFi module 102. The microphone 1042 can receive sound (audio data) in operating modes such as telephone call mode, recording mode, and voice recognition mode, and can process such sound into audio data. The processed audio (voice) data can be converted into a format that can be transmitted to a mobile communication base station via the radio frequency unit 101 in telephone call mode. The microphone 1042 can implement various types of noise cancellation (or suppression) algorithms to eliminate (or suppress) noise or interference generated during the reception and transmission of audio signals.

[0039] The mobile terminal 100 also includes at least one sensor 105, such as a light sensor, a motion sensor, and other sensors. Optionally, the light sensor includes an ambient light sensor and a proximity sensor. Optionally, the ambient light sensor can adjust the brightness of the display panel 1061 according to the ambient light level, and the proximity sensor can turn off the display panel 1061 and / or backlight when the mobile terminal 100 is moved to the ear. As a type of motion sensor, the accelerometer sensor can detect the magnitude of acceleration in various directions (generally three axes), and can detect the magnitude and direction of gravity when stationary. It can be used for applications that recognize the phone's posture (such as landscape / portrait switching, related games, magnetometer posture calibration), vibration recognition related functions (such as pedometer, tapping), etc. Other sensors that may be configured in the phone, such as fingerprint sensors, pressure sensors, iris sensors, molecular sensors, gyroscopes, barometers, hygrometers, thermometers, and infrared sensors, will not be described in detail here.

[0040] The display unit 106 is used to display information input by the user or information provided to the user. The display unit 106 may include a display panel 1061, which may be configured in the form of a liquid crystal display (LCD), an organic light-emitting diode (OLED), or the like.

[0041] User input unit 107 can be used to receive input numerical or character information, and generate key signal inputs related to user settings and function control of the mobile terminal. Optionally, user input unit 107 may include touch panel 1071 and other input devices 1072. Touch panel 1071, also known as touch screen, can collect touch operations on or near the user (such as operations performed by the user using a finger, stylus, or any suitable object or accessory on or near touch panel 1071), and drive corresponding connection devices according to a pre-set program. Touch panel 1071 may include two parts: a touch detection device and a touch controller. Optionally, the touch detection device detects the user's touch position and the signal generated by the touch operation, and transmits the signal to the touch controller; the touch controller receives touch information from the touch detection device, converts it into touch point coordinates, sends it to processor 110, and can receive and execute commands sent by processor 110. In addition, touch panel 1071 can be implemented using various types such as resistive, capacitive, infrared, and surface acoustic wave. In addition to the touch panel 1071, the user input unit 107 may also include other input devices 1072. Optionally, other input devices 1072 may include, but are not limited to, one or more of the following: physical keyboard, function keys (such as volume control buttons, power buttons, etc.), trackball, mouse, joystick, etc., without being specifically limited here.

[0042] Optionally, the touch panel 1071 may cover the display panel 1061. When the touch panel 1071 detects a touch operation on or near it, it transmits the information to the processor 110 to determine the type of touch event. Subsequently, the processor 110 provides corresponding visual output on the display panel 1061 based on the type of touch event. Although in Figure 1 In this embodiment, the touch panel 1071 and the display panel 1061 are two independent components to realize the input and output functions of the mobile terminal. However, in some embodiments, the touch panel 1071 and the display panel 1061 can be integrated to realize the input and output functions of the mobile terminal. The specific implementation is not limited here.

[0043] Interface unit 108 serves as an interface through which at least one external device can connect to mobile terminal 100. For example, the external device may include a wired or wireless headset port, an external power supply (or battery charger) port, a wired or wireless data port, a memory card port, a port for connecting a device with an identification module, an audio input / output (I / O) port, a video I / O port, a headphone port, and so on. Interface unit 108 may be used to receive input (e.g., data, power, etc.) from the external device and transmit the received input to one or more elements within mobile terminal 100, or it may be used to transmit data between mobile terminal 100 and the external device.

[0044] The memory 109 can be used to store software programs and various data. The memory 109 may primarily include a program storage area and a data storage area. Optionally, the program storage area may store the operating system, applications required for at least one function (such as sound playback, image playback, etc.), etc.; the data storage area may store data created based on the use of the mobile phone (such as audio data, phonebook, etc.). Furthermore, the memory 109 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0045] The processor 110 is the control center of the mobile terminal. It connects various parts of the mobile terminal via various interfaces and lines. By running or executing software programs and / or modules stored in the memory 109, and by calling data stored in the memory 109, it performs various functions and processes data of the mobile terminal, thereby providing overall monitoring of the mobile terminal. The processor 110 may include one or more processing units; preferably, the processor 110 may integrate an application processor and a modem processor. Optionally, the application processor mainly handles the operating system, user interface, and applications, while the modem processor mainly handles wireless communication. It is understood that the modem processor may not be integrated into the processor 110.

[0046] The mobile terminal 100 may also include a power supply 111 (such as a battery) that supplies power to various components. Preferably, the power supply 111 can be logically connected to the processor 110 through a power management system, thereby enabling functions such as charging, discharging, and power consumption management through the power management system.

[0047] although Figure 1 As not shown, the mobile terminal 100 may also include a Bluetooth module, etc., which will not be described in detail here.

[0048] To facilitate understanding of the embodiments of this application, the communication network system on which the mobile terminal of this application is based is described below.

[0049] Please see Figure 2 , Figure 2 This application provides a communication network system architecture diagram. The communication network system is an LTE system based on the universal mobile communication technology. The LTE system includes a UE (User Equipment) 201, an E-UTRAN (Evolved UMTS Terrestrial Radio Access Network) 202, an EPC (Evolved Packet Core) 203, and the operator's IP services 204, which are connected in sequence.

[0050] Optionally, UE201 can be the aforementioned terminal 100, which will not be described in detail here.

[0051] E-UTRAN202 includes eNodeB2021 and other eNodeB2022s. Optionally, eNodeB2021 can connect to other eNodeB2022s via backhaul (e.g., X2 interface). eNodeB2021 connects to EPC203 and can provide UE201 with access to EPC203.

[0052] EPC203 may include an MME (Mobility Management Entity) 2031, an HSS (Home Subscriber Server) 2032, other MMEs 2033, an SGW (Serving Gateway) 2034, a PGW (Packet Data Network Gateway) 2035, and a PCRF (Policy and Charging Rules Function) 2036, etc. Optionally, MME2031 is the control node that handles signaling between UE201 and EPC203, providing bearer and connection management. HSS2032 is used to provide registers to manage functions such as the Home Location Register (not shown in the figure) and stores user-specific information such as service characteristics and data rates. All user data can be sent through SGW2034. PGW2035 can provide UE 201 IP address allocation and other functions. PCRF2036 is the policy and charging control decision point for service data flow and IP bearer resources. It selects and provides available policy and charging control decisions for the policy and charging enforcement function unit (not shown in the figure).

[0053] IP services 204 may include the Internet, intranet, IMS (IP Multimedia Subsystem), or other IP services.

[0054] Although the above description uses the LTE system as an example, those skilled in the art should understand that this application is not only applicable to the LTE system, but also to other wireless communication systems, such as GSM, CDMA2000, WCDMA, TD-SCDMA, and future new network systems (such as 5G), etc., without limitation.

[0055] Based on the above-described mobile terminal hardware structure and communication network system, various embodiments of this application are proposed.

[0056] The protection circuit provided in this application embodiment is disposed on the mainboard of the smart terminal. In one embodiment, the protection circuit provided in this application includes an overcurrent protection module 310 and a current limiting protection module 320. The overcurrent protection module 310 is electrically connected between the system power supply of the mainboard and the first load module, and is used to disconnect the power supply path between the system power supply and the first load module when a short circuit occurs in the first load module. The current limiting protection module 320 is electrically connected between the power management module of the mainboard and the second load module, and is used to limit the current flowing into the second load module when a short circuit occurs in the second load module. In this application embodiment, the first load module and the second load module are disposed on the sub-board of the smart terminal.

[0057] In this embodiment, by adding an overcurrent protection module 310 and a current limiting protection module 320 to the main board, the sub-board can shut off the associated power supply or limit the current consumption of the associated power supply through the protection circuit when the sub-board is short-circuited due to water ingress or component failure, thereby avoiding faults such as the device failing to start or restart due to power short circuit on the sub-board.

[0058] Please see Figure 3 , Figure 3 This is a circuit diagram of an overcurrent protection module provided in an embodiment of this application.

[0059] In this embodiment, the overcurrent protection module 310 includes an overcurrent protection chip OCP IC and peripheral circuitry electrically connected to the overcurrent protection chip OCP IC.

[0060] Specifically, the overcurrent protection chip OCP IC includes a voltage input terminal VIN, a voltage output terminal VOUT, an enable terminal EN, an overcurrent flag output terminal OCP_FLAG, and a current setting terminal ISET. The voltage input terminal VIN is electrically connected to the system power supply of the motherboard to receive the power supply voltage output by the system power supply. The voltage output terminal VOUT is electrically connected to the first load module to provide power to the first load module when it is operating normally. Both the enable terminal EN and the overcurrent flag output terminal OCP_FLAG are electrically connected to the control module on the motherboard. When the overcurrent protection chip OCP IC detects a short circuit in the first load module, it outputs a low-level logic signal through the overcurrent flag output terminal OCP_FLAG, triggering the control module to disable the enable signal input to the enable terminal EN, thus disconnecting the power supply path between the system power supply and the first load module.

[0061] In a practical application scenario, the first load module is directly powered by the system power supply. For example, the first load module can be an audio power amplifier integrated circuit, and the system power supply is a charging power module. Under normal operation, the current requirement of the audio power amplifier integrated circuit is less than or equal to 2.2A. If the audio power amplifier integrated circuit short-circuits due to water ingress or device failure, it will draw a current greater than the overcurrent protection threshold of the charging power module from the charging power supply. In previous solutions without an overcurrent protection module, a short circuit in the audio power amplifier integrated circuit would directly cause the field-effect transistor inside the charging power module, used to control the battery connection, to shut down, putting the entire device's system power supply into a power-off state, thus preventing the device from powering on and affecting the use of other functions. If the overcurrent protection threshold of the charging power module is increased, the sub-board carrying the first load module may continuously overheat, posing a risk of burning out and exploding. Therefore, in this embodiment, an overcurrent protection module 310 is added between the system power supply and the first load module, so that when the first load module short-circuits due to water ingress or device failure, the overcurrent protection module 310 cuts off the power supply path of the system power supply, preventing the device from failing to power on.

[0062] In this embodiment, the peripheral circuit includes a pull-up resistor R. u and current limiting protection threshold resistor R ISET Pull-up resistor R u One end is electrically connected to the overcurrent flag output terminal OCP_FLAG of the overcurrent protection chip OCP IC, and a pull-up resistor R u The other end is electrically connected to the reference power supply VIO. Pull-up resistor R u This logic level is used to pull the overcurrent flag output terminal OCP_FLAG high when the first load module is operating normally. Current limiting protection threshold resistor R ISET It is electrically connected to the ISET terminal of the overcurrent protection chip OCP IC to set the current limit threshold of the overcurrent protection chip OCP IC.

[0063] In one embodiment, the internal circuitry of the selected overcurrent protection chip OCP IC is as follows: Figure 4As shown. The overcurrent protection chip includes a switching circuit, which comprises a first field-effect transistor (FET) and a second FET. The drain of the first FET is electrically connected to the voltage input terminal VIN of the overcurrent protection chip, and the source of the first FET is electrically connected to the source of the second FET. The drain of the second FET is electrically connected to the voltage output terminal VOUT of the overcurrent protection chip. When the circuit is operating, the input voltage enters the overcurrent protection chip through the VIN terminal. After passing through the switching circuit and undergoing filtering and regulation, it supplies power to the load through the VOUT terminal. Simultaneously, a portion of the current flows through a test resistor. The driver detects the current magnitude by monitoring the voltage drop across the test resistor. If the current exceeds the current limit threshold set through the ISET terminal, the current limit module is triggered. The control logic module reports the overcurrent status to the external device through the OCP_FLAG pin and cuts off the power supply according to the control signal on the EN pin to protect the circuit. Furthermore, if the output voltage is too high or the chip overheats, the overvoltage protection module and the thermal shutdown module will also trigger protection mechanisms.

[0064] In the aforementioned overcurrent protection chip OCP IC system, the overcurrent flag output terminal OCP_FLAG is an open-drain output. Therefore, when the overcurrent protection chip OCP IC is working normally, a pull-up resistor R is required. u When the logic level of the overcurrent flag output is pulled high, the overcurrent protection chip OCP IC will pull the logic level of the overcurrent flag output low to notify the control module of the short-circuit fault in the first load module. In practical applications, when the control module detects a low-level signal at the overcurrent flag output, it can control the system to generate a pop-up window to remind the user that there is a short-circuit fault on the secondary board, and some functions are temporarily unavailable, requiring timely repair. At the same time, the control module keeps the enable signal of the enable terminal EN in a low-level state, shutting down the power supply path by disabling the overcurrent protection chip OCP IC, preventing the output current of the system power supply from flowing into the first load module. After the power supply is cut off, to confirm whether the short circuit fault of the first load module still exists, the control module can set the enable signal to high level after a preset interval, so that the overcurrent protection chip OCP IC will re-perform overcurrent detection. If the overcurrent flag output continues to output a low level signal, the enable signal will be set to low level again, and the overcurrent protection chip OCP IC will be turned off again. If the overcurrent flag output still reports a low level within a preset number of consecutive times, the preset interval time will be increased. This can avoid the problem of reduced battery life caused by short circuit of the load module on the secondary board.

[0065] In one embodiment of this application, the current limiting protection threshold resistor R ISET The correspondence between ILIM and the current limiting threshold is: ILIM = ((0.4 / R) ISET (X2500); where ILIM is the current limiting threshold, RISET For current limiting protection threshold resistor R ISET The resistance value. For example, if the preset current limiting threshold is 2.2A, then a current limiting protection threshold resistor with a resistance value of 450Ω 1% can be selected.

[0066] In this embodiment, the peripheral circuit also includes an input voltage regulator and filter capacitor C. in and / or output voltage regulator capacitor C out Input voltage regulator capacitor C in Electrically connected to the voltage input terminal VIN of the overcurrent protection chip OCP IC, it provides a stable input voltage, and the output voltage regulator and filter capacitor C... out It is electrically connected to the voltage output terminal VOUT of the overcurrent protection chip OCP IC to provide a stable output voltage. This is achieved by setting the input voltage regulator capacitor C. in and output voltage regulator filter capacitor C out This can prevent ripple voltage in the system power supply path and instantaneous load tapping from causing false reporting by the overcurrent protection chip OCP IC, thus interrupting current transmission.

[0067] Please see Figure 5 , Figure 5 This is a circuit diagram of a current limiting protection module provided in an embodiment of this application.

[0068] In this embodiment, the current limiting protection module 320 includes multiple current limiting resistors. One end of each current limiting resistor is electrically connected to the power management module on the motherboard, and the other end of each current limiting resistor is electrically connected to the corresponding load component in the second load module.

[0069] In a practical application scenario, the second load module distributes power through a Power Management Unit Integrated Circuit (PMU IC). For example, the second load module may include a radio frequency (RF) switch integrated circuit, a headphone switch integrated circuit, a fingerprint module, etc. Accordingly, different load components require specific voltage rails from the PMU IC. For instance, the voltage rails corresponding to the RF switch integrated circuit are VIO18 and VIO28, the voltage rail corresponding to the Type-C headphone switch integrated circuit is VUSB, and the voltage rail corresponding to the fingerprint module is VFP. The device's response differs depending on the integrated circuit (IC) with different functions experiencing a short circuit. For example, if a load component connected to VIO18 short-circuits, the device may repeatedly restart because the current drawn after the load component short-circuits exceeds the PMU IC's limit, causing the PMU IC to reset, and the system needs to be powered on again.

[0070] Since different load components have different voltage and current requirements, current-limiting resistors of different values ​​can be selected according to actual application needs. For example, when the RF switch IC operates with a current consumption of less than 200uA, the current-limiting resistors R1 / R2 can be selected as 1K, and the voltage drop caused by the current-limiting resistors is only about 0.2V. When the load component RF switch IC fails and short-circuits, R1 / R2 can limit the current drawn from the PMU IC, that is, a maximum of only 1.8mA can be drawn from VIO18 and 2.8mA from VIO28, so it will not affect the normal operation of the device. Similarly, under the condition of ensuring the normal operation of the Type-C headphone switch IC and fingerprint module, R3 / R4 can be selected as 33R or 100R current-limiting resistors, which can draw a maximum of 100mA or 33mA from the PMU IC, still ensuring the normal operation of the device.

[0071] Please see Figure 6 , Figure 6 This is a structural block diagram of a smart terminal provided in an embodiment of this application. This application also provides a smart terminal, which includes a motherboard and a sub-board. The motherboard includes a system power supply, a control module, a power management module, and a protection circuit as described in the above embodiments. The sub-board includes a first load module and a second load module. The first load module is directly powered by the system power supply, and the second load module receives power through the power management module.

[0072] The embodiments of the smart terminal provided in this application may include all the technical features of any of the above-described protection circuit embodiments. The extended and explained contents of the specification are basically the same as the embodiments of the above methods, and will not be repeated here.

[0073] It is understood that the above scenarios are merely examples and do not constitute a limitation on the application scenarios of the technical solutions provided in the embodiments of this application. The technical solutions of this application can also be applied to other scenarios. For example, as those skilled in the art will know, with the evolution of system architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0074] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0075] The units in the device of this application embodiment can be merged, divided, and deleted according to actual needs.

[0076] In this application, the same or similar terms, concepts, technical solutions and / or application scenario descriptions are generally described in detail only when they appear for the first time. When they appear again, they are generally not repeated for the sake of brevity. When understanding the technical solutions and other contents of this application, the same or similar terms, concepts, technical solutions and / or application scenario descriptions that are not described in detail later can be referred to their previous relevant detailed descriptions.

[0077] In this application, the descriptions of the various embodiments have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0078] The technical features of the present application can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the present application.

[0079] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A protection circuit, characterized in that, Located on the motherboard of the smart terminal, the motherboard also has a system power supply, and the protection circuit includes an overcurrent protection module. The overcurrent protection module is electrically connected between the system power supply and the first load module, and is used to disconnect the power supply path between the system power supply and the first load module when a short circuit occurs in the first load module.

2. The protection circuit according to claim 1, characterized in that, The overcurrent protection module includes an overcurrent protection chip; The voltage input terminal of the overcurrent protection chip is electrically connected to the system power supply, the voltage output terminal of the overcurrent protection chip is electrically connected to the first load module, and the enable terminal and overcurrent flag output terminal of the overcurrent protection chip are both electrically connected to the control module on the motherboard.

3. The protection circuit according to claim 2, characterized in that, The overcurrent protection module also includes peripheral circuitry electrically connected to the overcurrent protection chip; The peripheral circuit includes a pull-up resistor, one end of which is electrically connected to the overcurrent flag output terminal of the overcurrent protection chip, and the other end of which is electrically connected to the reference power supply.

4. The protection circuit according to claim 3, characterized in that, The peripheral circuit also includes a current limiting protection threshold resistor, which is electrically connected to the current setting terminal of the overcurrent protection chip and is used to set the current limiting threshold of the overcurrent protection chip.

5. The protection circuit according to claim 3 or 4, characterized in that, The peripheral circuit also includes an input voltage regulator and / or an output voltage regulator. The input voltage regulator and filter capacitor is electrically connected to the voltage input terminal of the overcurrent protection chip, and the output voltage regulator and filter capacitor is electrically connected to the voltage output terminal of the overcurrent protection chip.

6. The protection circuit according to claim 2, characterized in that, The overcurrent protection chip includes a switching circuit, which includes a first field-effect transistor and a second field-effect transistor. The drain of the first field-effect transistor is electrically connected to the voltage input terminal of the overcurrent protection chip, and the source of the first field-effect transistor is electrically connected to the source of the second field-effect transistor; the drain of the second field-effect transistor is electrically connected to the voltage output terminal of the overcurrent protection chip.

7. The protection circuit according to claim 1, characterized in that, The protection circuit also includes a current limiting protection module; The current limiting protection module is electrically connected between the power management module and the second load module on the motherboard, and is used to limit the current flowing into the second load module when a short circuit occurs in the second load module.

8. The protection circuit according to claim 7, characterized in that, The current limiting protection module includes at least two current limiting resistors. One end of each current limiting resistor is electrically connected to the power management module, and the other end of each current limiting resistor is electrically connected to the corresponding load component in the second load module.

9. A smart terminal, characterized in that, The smart terminal includes a motherboard and a sub-board. The motherboard includes a system power supply, a control module, a power management module, and a protection circuit as described in any one of claims 1 to 8. The sub-board includes a first load module and a second load module.

10. The smart terminal according to claim 9, characterized in that, The first load module is directly powered by the system power supply, while the second load module receives power through the power management module.

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