Interface protection circuit and electronic device

Abstract

The present application relates to the technical field of electronics, and provides an interface protection circuit and an electronic device, for use in protecting a functional chip coupled to a CC pin if the CC pin of a Type-C interface is short-circuited with a VBUS pin in the process of the electronic device charging by means of the Type-C interface. The interface circuit may comprise a first protection circuit and / or a second protection circuit. A first end of the first protection circuit is coupled to the CC pin, and a second end of the first protection circuit is coupled to a power supply of the electronic device. A first end of the second protection circuit is coupled to the CC pin, and a second end of the second protection circuit is coupled to the VBUS pin. In the process of the electronic device charging by means of the Type-C interface, if the CC pin of the Type-C interface is short-circuited with the VBUS pin, the first protection circuit and / or the second protection circuit work / works, so that the electronic device suppresses a surge acting on the CC pin.

Description

Interface protection circuit and electronic equipment

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on December 20, 2023, with application number 202311764769.6 and invention name “An interface protection circuit and electronic device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to the field of electronic technology, and in particular to an interface protection circuit and an electronic device. Background Art

[0003] Currently, the Type-C universal serial bus (USB) interface (hereinafter referred to as the Type-C interface) has become a widely used interface on electronic devices. Electronic devices can connect to other devices for data communication via a data cable (such as a USB cable) inserted into the Type-C interface. Electronic devices can also connect to other devices or connect to a power source for charging via a data cable inserted into the Type-C interface.

[0004] The physical structure of the Type-C interface shows that the configuration channel (CC) pin and the voltage bus (VBUS) pin are adjacent to each other. During use, the CC pin and the VBUS pin may short-circuit, which can damage the functional chip connected to the CC pin.

[0005] Summary of the Invention

[0006] An embodiment of the present application provides an interface protection circuit and an electronic device, which are used to protect a functional chip coupled to the CC pin when the CC pin of the Type-C interface is short-circuited with the VBUS pin during charging of the electronic device through the Type-C interface.

[0007] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0008] In a first aspect, an interface protection circuit is provided. The interface protection circuit is applied to an electronic device, the electronic device including a function chip and a Type-C interface. The Type-C interface may include a CC pin and a VBUS pin. The CC pin of the Type-C interface is coupled to the function chip, and the VBUS pin of the Type-C interface is coupled to a power supply of the electronic device.

[0009] Specifically, the interface protection circuit may include: a first protection circuit and / or a second protection circuit.

[0010] The first end of the first protection circuit is coupled to the CC pin of the Type-C interface, and the second end of the first protection circuit is coupled to the power supply of the electronic device. When the difference between the voltage at the first end of the first protection circuit and the voltage at the second end of the first protection circuit is greater than a preset voltage, and the voltage at the first end of the first protection circuit is greater than the voltage at the second end of the first protection circuit, the first protection circuit operates to suppress surges acting on the CC pin of the Type-C interface.

[0011] The first end of the second protection circuit is coupled to the CC pin, and the second end of the second protection circuit is coupled to the VBUS pin of the Type-C interface. When the difference between the voltage at the first end of the second protection circuit and the voltage at the second end of the second protection circuit is greater than a preset voltage, and the voltage at the first end of the second protection circuit is greater than the voltage at the second end of the second protection circuit, the second protection circuit operates to enable the electronic device to suppress surges acting on the CC pin of the Type-C interface.

[0012] When an electronic device is charging via a Type-C port, if the CC pin of the Type-C port is short-circuited with the VBUS pin of the Type-C port, the CC pin of the Type-C port will be subjected to a surge. Specifically, the voltage at the first terminal of the first protection circuit is a surge voltage, and the voltage at the first terminal of the second protection circuit is a surge voltage. Typically, the surge voltage is greater than the power supply voltage, and the difference between the surge voltage and the power supply voltage is greater than a preset voltage. The surge voltage is greater than the voltage on the VBUS pin of the Type-C port, and the difference between the surge voltage and the voltage on the VBUS pin of the Type-C port is greater than a preset voltage. Therefore, the first protection circuit and / or the second protection circuit are operational. When the first protection circuit and / or the second protection circuit are operational, the electronic device suppresses surges acting on the CC pin of the Type-C port, thereby clamping the voltage on the CC pin of the Type-C port within a safe voltage range. This can mitigate voltage ringing on the CC pin of the Type-C port and prevent damage to the functional chip coupled to the CC pin of the Type-C port due to a sudden voltage surge or latch-up caused by an excessively large surge voltage slope.

[0013] In a possible implementation of the first aspect, the first protection circuit in the interface protection circuit includes a first diode and a first absorption sub-circuit. Specifically, the anode of the first diode is coupled to the CC pin of the Type-C interface, the cathode of the first diode is coupled to the first end of the first absorption sub-circuit, and the second end of the first absorption sub-circuit is coupled to a power supply of the electronic device.

[0014] Specifically, the preset voltage can be the forward conduction voltage of the first diode. When the difference between the voltage at the first terminal of the first protection circuit and the voltage at the second terminal of the first protection circuit is greater than the preset voltage, and the voltage at the first terminal of the first protection circuit is greater than the voltage at the second terminal of the first protection circuit, the first diode conducts. In this way, the first absorption sub-circuit can suppress surges on the CC pin of the Type-C interface.

[0015] In another possible implementation of the first aspect, the first absorption sub-circuit includes a first resistor, wherein a first end of the first resistor is coupled to the cathode of the first diode, and a second end of the first resistor is coupled to a power supply of the electronic device.

[0016] Specifically, the first resistor suppresses the surge on the CC pin of the Type-C interface by converting electrical energy into thermal energy.

[0017] In another possible implementation of the first aspect, the first absorption subcircuit includes a first capacitor, a first end of the first capacitor is coupled to the cathode of the first diode, and a second end of the first capacitor is coupled to a power supply of the electronic device.

[0018] Specifically, the first capacitor suppresses surges on the CC pin of the Type-C interface by rapidly charging or discharging.

[0019] In another possible implementation of the first aspect, the first absorption subcircuit includes a first resistor and a first capacitor. The first resistor and the first capacitor are connected in parallel or in series. The cathode of the first diode is coupled to a power supply of the electronic device through the first resistor and the first capacitor.

[0020] In another possible implementation of the first aspect, the electronic device in the present application includes a second absorption sub-circuit. The second absorption sub-circuit is coupled to the VBUS pin of the Type-C interface. The second protection circuit in the interface protection circuit includes a second diode. The anode of the second diode is coupled to the CC pin of the Type-C interface, and the cathode of the second diode is coupled to the VBUS pin of the Type-C interface.

[0021] Specifically, the second diode and the first diode can be of the same type, and therefore have the same forward voltage. Therefore, when the difference between the voltage at the first terminal of the second protection circuit and the voltage at the second terminal of the second protection circuit is greater than a preset voltage, and the voltage at the first terminal of the second protection circuit is greater than the voltage at the second terminal of the second protection circuit, the second diode conducts. In this way, the second absorption sub-circuit can suppress surges on the CC pin of the Type-C interface.

[0022] In another possible implementation of the first aspect, the second absorption subcircuit includes a second capacitor, wherein a first end of the second capacitor is coupled to the cathode of the second diode, and a second end of the second capacitor is coupled to a ground terminal of the electronic device.

[0023] Specifically, the second capacitor suppresses surges on the CC pin of the Type-C interface by rapidly charging or discharging.

[0024] In another possible implementation of the first aspect, the second absorption sub-circuit includes a second resistor and a second capacitor. The second resistor and the second capacitor are connected in series. A first end of the series-connected second resistor and capacitor is coupled to the cathode of the second diode, and a second end of the series-connected second resistor and capacitor is coupled to a ground terminal of the electronic device.

[0025] In another possible implementation of the first aspect, the second absorption sub-circuit includes a second resistor and a second capacitor. The second resistor and the second capacitor are connected in parallel. A first end of the parallel-connected second resistor and second capacitor is coupled to the cathode of the second diode, and a second end of the parallel-connected second resistor and second capacitor is coupled to a ground terminal of the electronic device.

[0026] In a second aspect, the present application provides an electronic device. The electronic device includes: a power supply, a functional chip, a second absorption sub-circuit, a Type-C interface, and the interface protection circuit described in the first aspect and any possible implementation thereof. The Type-C interface includes a CC pin and a VBUS pin. The CC pin of the Type-C interface is coupled to the functional chip, and the VBUS pin of the Type-C interface is coupled to the power supply. The interface protection circuit includes a first protection circuit and / or a second protection circuit.

[0027] Specifically, a first end of the first protection circuit is coupled to the CC pin of the Type-C interface, and a second end of the first protection circuit is coupled to a power supply of the electronic device. A first end of the second protection circuit is coupled to the CC pin of the Type-C interface, and a second end of the second protection circuit is coupled to the VBUS pin of the Type-C interface.

[0028] Among them, the technical effects of the second aspect can refer to the technical effects of the first aspect and any of its implementation methods, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG1 is a schematic diagram of a charging scenario or a communication scenario in conventional technology;

[0030] FIG2 is a schematic diagram of a hardware structure of an electronic device in conventional technology;

[0031] FIG3 is a schematic diagram of pin distribution of a Type-C interface in conventional technology;

[0032] FIG4 is a second schematic diagram of the hardware structure of an electronic device in conventional technology;

[0033] FIG5 is a waveform diagram of a ringing effect in conventional technology;

[0034] FIG6 is a schematic diagram of a hardware structure of an electronic device provided in an embodiment of the present application;

[0035] FIG7 is a schematic diagram showing the effect of surge suppression on the CC pin of a Type-C interface provided by an electronic device according to an embodiment of the present application;

[0036] FIG8 is a schematic diagram of a hardware structure of an interface protection circuit according to an embodiment of the present application;

[0037] FIG9 is a second schematic diagram of the hardware structure of an interface protection circuit provided in an embodiment of the present application;

[0038] FIG10 is a third schematic diagram of the hardware structure of an interface protection circuit provided in an embodiment of the present application;

[0039] FIG11 is a second schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application;

[0040] FIG12 is a third schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application;

[0041] FIG13 is a fourth schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] The terms "first", "second", etc. involved in the embodiments of the present application are only used to distinguish features of the same type and cannot be understood as indicating relative importance, quantity, order, etc.

[0043] The terms "exemplary" or "for example" in the embodiments of this application are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0044] The terms "coupling" and "connection" involved in the embodiments of this application should be understood in a broad sense. For example, they may refer to a physical direct connection, or an indirect connection achieved through electronic devices, such as a connection achieved through resistors, inductors, capacitors or other electronic devices.

[0045] First, some concepts involved in the embodiments of this application are introduced.

[0046] Latch-up occurs due to the loop amplification effect of two bipolar junction transistors (BJTs) connected to each other in a complementary metal oxide semiconductor (CMOS) circuit. Specifically, when the current amplification factor of both BJTs is greater than 1, the current in the loop formed by the two BJTs is continuously amplified, causing the BJTs to withstand excessive current and burn out the circuit.

[0047] With technological advancements in the electronic device industry, USB interfaces have become widely used interfaces on electronic devices. As shown in Figure 1, one end of a USB cable 110 is connected to a USB interface on an electronic device 120, and the other end of the USB cable 110 is connected to a power source or other device 130. For example, the electronic device 120 can communicate data with other devices 130 via the USB cable 110. Furthermore, the electronic device 120 can charge the other device 130 via the USB cable 110, and / or the other device 130 can charge the electronic device 120 via the USB cable 110. When the electronic device 120 is connected to a power source via the USB cable 110, the power source can charge the electronic device 120 via the USB cable 110.

[0048] Among them, the electronic device can be a device with communication function and charging function. The electronic device can be mobile or fixed. The electronic device can be deployed on land (for example, indoors or outdoors, handheld or vehicle-mounted, etc.), on water (for example, ships, etc.), or in the air (for example, airplanes, balloons, etc.). The electronic device can be called user equipment (UE), access terminal, terminal unit, subscriber unit, terminal station, mobile station (MS), mobile station, terminal agent or terminal device, etc. For example, the electronic device can be a mobile phone, tablet computer, laptop computer, etc. The embodiments of the present application do not limit the specific type and structure of the electronic device. A possible structure of the electronic device is described below.

[0049] Figure 2 shows one of the hardware structure diagrams of an electronic device in conventional technology. As shown in A of Figure 2 , the electronic device 120 may include: a processor 210, a power supply 220, a function chip 230, a load module 240, and a USB interface 250.

[0050] Specifically, the processor 210 is coupled to the power supply 220 , the function chip 230 , the load module 240 , and the USB interface 250 . The power supply 220 is also coupled to the function chip 230 , the load module 240 , and the USB interface 250 . The function chip 230 is coupled to the USB interface 250 .

[0051] It should be understood that the structure illustrated in this embodiment does not constitute a specific limitation on the electronic device 120. In other embodiments, the electronic device 120 may include more or fewer components than illustrated, or may combine or separate certain components, or arrange the components differently. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0052] The processor 210 may include one or more processing units, for example, the processor 210 may include an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a memory, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural network processing unit (NPU). Different processing units may be independent devices or integrated into one or more processors. The controller may be the nerve center and command center of the electronic device 120. The controller may generate an operation control signal based on the instruction opcode and the timing signal to complete the control of instruction fetching and execution.

[0053] Processor 210 may also include a memory for storing instructions and data. In some embodiments, the memory in processor 210 is a cache memory. This memory can store instructions or data that have just been used or are being recycled by processor 210. If processor 210 needs to use the same instruction or data again, it can directly access the memory. This avoids duplicate accesses, reduces processor 210 latency, and thus improves system efficiency.

[0054] In which, referring to B in FIG2 in combination with A in FIG2 , the power supply 220 may include a first switching element 2201 , a battery 2202 , a first transient voltage suppressor (TVS) 2203 and a second transient voltage suppressor 2204 and a power management system (not shown in FIG2 ).

[0055] Specifically, the first switch element 2201 may be a metal-oxide-semiconductor field-effect transistor (MOS), such as an NMOS. The gate of the NMOS may be coupled to the functional chip 230, the first electrode of the NMOS may be coupled to the positive electrode of the battery 2202, and the second electrode of the NMOS may be coupled to the first end of the first transient voltage suppressor diode 2203 and the first end of the second transient voltage suppressor diode 2204. The second end of the first transient voltage suppressor diode 2203 and the second end of the second transient voltage suppressor diode 2204 may be coupled to the negative electrode of the battery 2202.

[0056] Typically, the first switching element 2201 can be in an on state. The first transient voltage suppressor diode 2203 can be a bidirectional transient voltage suppressor diode. The second transient voltage suppressor diode 2204 can be a unidirectional transient voltage suppressor diode, and the first end of the second transient voltage suppressor diode 2204 is a cathode, and the second end of the second transient voltage suppressor diode 2204 is an anode.

[0057] The battery can be coupled to the processor 210 through a power management system, so that the power management system can manage charging, discharging, power consumption, and other functions.

[0058] The function chip 230 can be used to control the logic related to the USB interface 250, but is not limited thereto. For example, the function chip 230 can be a USB interface management chip, and the function chip 230 can be connected to a pin (such as the CC pin) in the USB interface 250 to control the logic related to the pin (such as communication logic).

[0059] The load module 240 may include one or more of the following: a memory, an antenna, a communication submodule, a display screen, an audio submodule, a camera, and a sensor submodule, but is not limited thereto.

[0060] Specifically, the memory can be used to store computer executable program code, which includes instructions. The processor 210 executes various functional applications and data processing of the electronic device by running the instructions stored in the memory. The memory may include a program storage area and a data storage area. Among them, the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an interface display function, etc.). The data storage area can store data created during the use of the electronic device (such as notification messages), etc. In addition, the memory may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, a universal flash storage (UFS), etc.

[0061] In some embodiments, the antenna of the electronic device 120 is coupled to the communication module so that the electronic device 120 can communicate with a network and other devices via wireless communication technologies. The wireless communication technologies may include global system for mobile communications (GSM), general packet radio service (GPRS), code division multiple access (CDMA), wideband code division multiple access (WCDMA), time division code division multiple access (TD-SCDMA), long term evolution (LTE), BT, global navigation satellite system (GNSS), WLAN, NFC, FM, and / or IR technology. The GNSS may include global positioning system (GPS), Beidou navigation satellite system (BDS), global navigation satellite system (GLONASS), and / or Galileo satellite navigation system (GALILEO).

[0062] Electronic device 120 can implement display functions using a GPU, a display screen, and an application processor. A GPU is a microprocessor for image processing that connects the display screen and the application processor. The GPU is used to perform mathematical and geometric calculations for graphics rendering. The processor may include one or more GPUs, which execute program instructions to generate or modify display information.

[0063] A display screen is used to display images, videos, and the like. The display screen includes a display panel. The display panel can be a liquid crystal display (LCD), an organic light emitting diode (OLED), an active matrix organic light emitting diode (AMOLED), a flexible light emitting diode (FLED), a Mini LED, a Micro OLED, or a quantum dot light emitting diode (QLED).

[0064] The audio module is used to convert digital audio information into analog audio signal output, and is also used to convert analog audio input into digital audio signals. The audio module 160 can also be used to encode and decode audio signals. In some embodiments, the audio module can be provided in the processor 210, or some functional modules of the audio module can be provided in the processor 210.

[0065] A camera is used to capture still images or videos. The lens generates an optical image of an object and projects it onto a photosensitive element. The photosensitive element can be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) phototransistor. The photosensitive element converts the optical signal into an electrical signal, which is then passed to the ISP for conversion into a digital image signal. The ISP outputs the digital image signal to the DSP for processing. The DSP converts the digital image signal into an image signal in a standard format, such as RGB or YUV.

[0066] The sensor module may include at least one sensor, such as a light sensor, a motion sensor, a fingerprint sensor, a pressure sensor, or other sensors.

[0067] The USB interface 250 is an input / output interface for connecting the electronic device to other devices. There are various types of USB interfaces, such as mini USB interface, micro USB interface, Type-A USB interface, Type-B USB interface, and Type-C USB interface. Herein, the Type-C USB interface is referred to as the Type-C interface.

[0068] Figure 3 shows a schematic diagram of the pinout of a Type-C interface in conventional technology. The following describes the USB interface using the Type-C interface as an example.

[0069] As shown in Figure 3, the Type-C interface includes two sets of symmetrical pins. This design allows the Type-C interface to support both forward and reverse plugging. Specifically, these two sets of symmetrical pins may include:

[0070] Configuration channel (CC) pins: These pins are used to detect and identify connected devices. CC1 and CC2 are used to send and receive signals, respectively. When two devices connect, they send probe signals and perform a handshake to identify the type and role of the connected device.

[0071] In actual applications, when CC1 is a configuration pin, CC2 can be defined as a VCONN pin. Alternatively, when CC2 is a configuration pin, CC1 can be defined as a VCONN pin.

[0072] A set of auxiliary communication (SBU) pins: SBU1 and SBU2 are used for audio signal transmission and video signal synchronization. SBU1 and SBU2 are typically used to connect external devices such as headphones and speakers.

[0073] Two sets of USB 2.0 differential pair signal pins: differential pairs used for USB 2.0 connection to transmit data, namely: D+ pin and D- pin.

[0074] Two sets of receive (RX) differential pair pins: used to receive data, namely: RX1+, RX1-, RX2+, RX2-.

[0075] Two sets of transmit (TX) differential pair pins: used to send data, namely TX1+, TX1-, TX2+, and TX2-.

[0076] Four power bus (VBUS) pins: used to provide 5V, 9V, 15V, or 20V voltage.

[0077] Four ground (GND) pins: used to connect to the corresponding four VBUS pins respectively.

[0078] Figure 4 shows a second schematic diagram of the hardware structure of an electronic device in conventional technology. The following describes the connection relationship between the CC pin and VBUS pin in the Type-C interface and other components in the electronic device in conjunction with Figures 2 to 4.

[0079] As shown in FIG4 , the electronic device 120 may include a Type-C interface 410, a third transient voltage suppressor diode 420, at least one functional chip 230 (one functional chip is shown as an example in FIG4 ), a processor 210, and a power supply 220. The Type-C interface 410 may include a VBUS pin 4101, a CC pin 4102, a GND pin 4103, and other pins 4104. The third transient voltage suppressor diode 420 may be a bidirectional transient voltage suppressor diode or a unidirectional transient voltage suppressor diode. FIG4 illustrates the case where the third transient voltage suppressor diode 420 is a bidirectional transient voltage suppressor diode.

[0080] Specifically, the VBUS pin 4101 is coupled to the power supply terminal of the power supply 220. The CC pin 4102 is coupled to the output terminal of the function chip 230. The power supply terminal of the function chip 230 is coupled to the output terminal of the power supply 220. The output terminal of the function chip 230 can be coupled to the control terminal of the power supply 220, such as the output terminal of the function chip 230 is coupled to the control terminal of the first switching element 2201. The GND pin 4103 is coupled to the ground terminal of the electronic device 120. The processor 210 is coupled to the other pins 4104, the function chip 230, and the power supply 220. The first end of the third transient voltage suppressor diode 420 is coupled to the CC pin 4102, and the second end of the third transient voltage suppressor diode 420 is coupled to the ground terminal of the electronic device 120.

[0081] It should be noted that the other pins 4104 of the Type-C interface 410 refer to the pins of the Type-C interface 410 other than the VBUS pin 4101, the CC pin 4102, and the GND pin 4103. Each pin in the other pins 4104 can be directly or indirectly coupled to the processor 210, which is not limited in this embodiment of the present application.

[0082] It should be noted that when the function chip 230 is a USB interface management chip, the output terminal of the USB interface management chip may not be coupled to the control terminal of the power supply 220. In other words, the USB interface management chip may not control the power supply 220. In this case, the power supply 220 may be controlled by another function chip. In the embodiment of the present application, when the function chip 230 is a USB interface management chip, the USB interface management chip is coupled to the control terminal of the power supply 220 as an example.

[0083] In some scenarios, as shown in Figure 4 , the electronic device 120 further includes a second switch element 430. The VBUS pin 4101 is coupled to the power supply terminal of the power supply 220 via the second switch element 430. Typically, the second switch element 430 is in an on state.

[0084] Exemplarily, the second switch element 430 may be an NMOS with an overvoltage protection function. The gate of the NMOS may be coupled to the processor 210 (not shown in FIG. 4 ), the first electrode of the NMOS may be coupled to the VBUS pin 4101, and the second electrode of the NMOS may be coupled to the power supply terminal of the power supply 220.

[0085] Typically, the Type-C interface is small in size (e.g., 8.6mm × 2.6mm), resulting in a smaller spacing between the pins in the Type-C interface. Furthermore, as shown in Figure 3, the VBUS pin and CC pin are adjacent to each other in any group of pins in the Type-C interface. During use, liquids or debris may seep into the Type-C interface, potentially causing the CC pin and VBUS pin to short-circuit. When an electronic device is connected to a USB cable via the Type-C interface for charging, if the CC pin and VBUS pin are short-circuited, the inductance in the USB cable and the capacitance in the electronic device will form a resonant circuit, generating a surge (including surge voltage and surge current). The surge generated by the resonant circuit will act on the CC pin.

[0086] The surge voltage on the CC pin (e.g., 20V) is greater than the voltage on the VBUS pin (e.g., the surge voltage is 1.2 times the voltage on the VBUS pin), and the surge voltage is also greater than the power supply voltage. This means that when an electronic device is charging via a Type-C port connected to a USB cable, if the CC pin and VBUS pin are shorted, the CC pin will experience a ringing effect due to the step input voltage, subjecting the CC pin to a high voltage surge.

[0087] FIG5 is a waveform diagram showing a ringing effect in conventional technology.

[0088] As shown in Figure 5, when an electronic device is charged via a Type-C interface connected to a USB cable, and the CC pin and VBUS pin are short-circuited, the ringing effect generated on the CC pin corresponds to the ringing wave waveform. The first pulse (i.e., pulse A) has the highest peak value and the highest slope of the rising edge of the first pulse. The peak value of the first pulse can correspond to the sudden surge voltage applied to the CC pin. The slope of the rising edge of the first pulse indicates that the surge voltage on the CC pin occurred suddenly, and the slope of the rising edge of the first pulse indicates that the surge voltage had a large slope.

[0089] It can be seen that when an electronic device is charging through the Type-C interface, if the VBUS pin and the CC pin are short-circuited, the CC pin will be subjected to a surge voltage. Although the third transient voltage suppression diode 420 coupled to the CC pin can also suppress the surge voltage, the operating voltage of the third transient voltage suppression diode 420 is usually selected to be higher, which makes the clamping voltage of the third transient voltage suppression diode 420 higher, and thus cannot reduce the slope of the surge voltage, resulting in the sudden surge voltage still acting on the functional chip. The functional chip is a semiconductor device and is sensitive to the slope and absolute value of the surge voltage. The surge voltage may trigger a latch-up effect inside the functional chip, which may cause the functional chip to burn out and even affect the performance of the electronic device.

[0090] To this end, as shown in FIG6 , an embodiment of the present application provides an electronic device 600 including an interface protection circuit 610. The interface protection circuit 610 is located between the Type-C interface 410 and the function chip 230. Specifically, a first end of the interface protection circuit 610 can be coupled to the CC pin 4102 of the Type-C interface 410 and the output end of the function chip 230.

[0091] In some embodiments, the interface protection circuit 610 may include a first protection circuit 620. The first end of the first protection circuit 620 is the first end of the interface protection circuit 610, and the second end of the first protection circuit 620 is the second end of the interface protection circuit 610. The second end of the first protection circuit 620 is coupled to the power supply 220. When the difference between the voltage at the first end of the interface protection circuit 610 and the voltage at the second end of the interface protection circuit 610 is greater than a preset voltage (e.g., 0.6V or 0.7V), and the voltage at the first end of the interface protection circuit 610 is greater than the voltage at the second end of the interface protection circuit 610, the first protection circuit 620 operates. Otherwise, the first protection circuit 620 does not operate. In this case, the operation of the first protection circuit 620 is equivalent to the operation of the interface protection circuit. Similarly, the inoperability of the first protection circuit 620 is equivalent to the inoperability of the interface protection circuit.

[0092] In other embodiments, the interface protection circuit 610 may include a second protection circuit 630. The first end of the second protection circuit 630 is the first end of the interface protection circuit 610, and the second end of the second protection circuit 630 is the third end of the interface protection circuit 610. The second end of the second protection circuit 630 is coupled to the VBUS pin 4101 of the Type-C interface 410. When the difference between the voltage at the first end of the interface protection circuit 610 and the voltage at the third end of the interface protection circuit 610 is greater than a preset voltage, and the voltage at the first end of the interface protection circuit 610 is greater than the voltage at the third end of the interface protection circuit 610, the second protection circuit 630 operates. Otherwise, the second protection circuit 630 does not operate. At this time, the operation of the second protection circuit 630 is equivalent to the operation of the interface protection circuit. Similarly, the non-operation of the second protection circuit 630 is equivalent to the non-operation of the interface protection circuit.

[0093] In other embodiments, the interface protection circuit 610 may include both a first protection circuit 620 and a second protection circuit 630. When the difference between the voltage at the first terminal of the interface protection circuit 610 and the voltage at the second terminal of the interface protection circuit 610 is greater than a preset voltage (e.g., 0.6V or 0.7V), and the voltage at the first terminal of the interface protection circuit 610 is greater than the voltage at the second terminal of the interface protection circuit 610, and / or the difference between the voltage at the first terminal of the interface protection circuit 610 and the voltage at the third terminal of the interface protection circuit 610 is greater than a preset voltage, and the voltage at the first terminal of the interface protection circuit 610 is greater than the voltage at the third terminal of the interface protection circuit 610, the interface protection circuit 610 operates. Otherwise, the interface protection circuit 610 does not operate.

[0094] 6 illustrates an example in which the interface protection circuit 610 includes both a first protection circuit 620 and a second protection circuit 630. In conjunction with FIG4 and FIG6 , the second end of the second protection circuit 630 can be coupled to the VBUS pin 4101, and the first end of the second switch element 430 (i.e., the first electrode of the NMOS) is coupled to the VBUS pin 4101. In other words, the second end of the second protection circuit 630 can be directly coupled to the VBUS pin 4101. Alternatively, the second end of the second protection circuit 630 can be coupled to the second end of the second switch element 430 (i.e., the second electrode of the NMOS), and the first end of the second switch element 430 is coupled to the VBUS pin 4101. In other words, the second end of the second protection circuit 630 can be coupled to the VBUS pin 4101 via the second switch element 430.

[0095] Specifically, when the electronic device 600 is charging via the Type-C interface 410, if the VBUS pin 4101 of the Type-C interface 410 is not short-circuited with the CC pin 4102 of the Type-C interface 410, the voltage at the first end of the first protection circuit 620 is equal to the voltage of the CC pin 4102 of the Type-C interface 410, and the voltage at the first end of the second protection circuit 630 is equal to the voltage of the CC pin 4102 of the Type-C interface 410. Typically, the voltage at the CC pin 4102 of the Type-C interface 410 is lower than the voltage of the power supply 220. The voltage at the second end of the first protection circuit 620 is substantially equal to the output voltage of the power supply 220. The voltage at the second end of the second protection circuit 630 is equal to the voltage of the VBUS pin 4101 of the Type-C interface 410. Typically, the voltage at the VBUS pin 4101 of the Type-C interface 410 is substantially equal to the voltage of the power supply 220.

[0096] It can be seen that during the above charging process, if the VBUS pin 4101 of the Type-C interface 410 is not short-circuited with the CC pin 4102 of the Type-C interface 410, the voltage at the first end of the first protection circuit 620 is less than the voltage at the second end of the first protection circuit 620, and the voltage at the first end of the second protection circuit 630 is substantially equal to the voltage at the second end of the second protection circuit 630. Therefore, the interface protection circuit 610 does not work.

[0097] When the electronic device 600 is charging via the Type-C interface 410, if the VBUS pin 4101 of the Type-C interface 410 is short-circuited with the CC pin 4102 of the Type-C interface 410, the voltage at the first terminal of the first protection circuit 620 is the aforementioned surge voltage, and the voltage at the first terminal of the second protection circuit 630 is the aforementioned surge voltage. The voltage at the second terminal of the first protection circuit 620 is substantially equal to the output voltage of the power supply 220. The voltage at the second terminal of the second protection circuit 630 is the voltage at the VBUS pin 4101. Typically, the difference between the surge voltage and the voltage of the power supply 220 is greater than a preset voltage, and the difference between the surge voltage and the voltage of the VBUS pin 4101 is greater than the preset voltage, thus activating the interface protection circuit 610. When the interface protection circuit 610 is working, the electronic device 600 will suppress the surge acting on the CC pin 4102, thereby clamping the voltage on the CC pin 4102 of the Type-C interface 410 within a safe voltage value range. This can slow down the voltage ringing on the CC pin 4102 of the Type-C interface 410 and prevent the functional chip 230 from being burned due to a sudden voltage increase or an internal latch-up effect caused by an excessive surge voltage slope.

[0098] FIG7 is a schematic diagram showing the effect of surge suppression on the CC pin of the Type-C interface by an electronic device provided in an embodiment of the present application.

[0099] In conjunction with FIG5 , as shown in FIG7 , in an embodiment of the present application, after the interface protection circuit operates, the electronic device suppresses the surge on the CC pin of the Type-C interface, thereby reducing the voltage on the CC pin of the Type-C interface and reducing the slope of the rising edge of pulse A (i.e., limiting the slope of the surge voltage). This can reduce the impact on the function chip 230 and prevent the function chip 230 from being burned due to a sudden voltage increase or an internal latch-up effect caused by an excessively large surge voltage slope.

[0100] The interface protection circuit provided in the embodiment of the present application is described in detail below with reference to FIG8-FIG13.

[0101] FIG8 shows one of the hardware structure diagrams of an interface protection circuit provided in an embodiment of the present application.

[0102] Optionally, as shown in FIG8 , the interface protection circuit includes a first protection circuit 620 . The first protection circuit 620 may include: a first diode 810 and a first absorption sub-circuit 820 .

[0103] The anode of the first diode 810 is coupled to the CC pin 4102 and the output terminal of the function chip 230. The cathode of the first diode 810 is coupled to the first terminal of the first absorption sub-circuit 820. The second terminal of the first absorption sub-circuit 820 is coupled to the power supply terminal of the power supply 220. The input terminal of the power supply 220 is coupled to the VBUS pin 4101. The output terminal of the power supply 220 is coupled to the power supply terminal of the function chip 230.

[0104] During the aforementioned charging process, when the CC pin 4102 and the VBUS pin 4101 are not short-circuited, the aforementioned circuit structure shows that the voltage at the anode of the first diode 810 is equal to the voltage of the CC pin 4102. Because the voltage at the CC pin 4102 is lower than the voltage of the power supply 220, the voltage at the anode of the first diode 810 is lower than the voltage of the power supply 220. Furthermore, the voltage at the cathode of the first diode 810 is substantially equal to the voltage of the power supply 220. Therefore, during the aforementioned charging process, when the CC pin 4102 and the VBUS pin 4101 are not short-circuited, the voltage at the anode of the first diode 810 is lower than the voltage at the cathode of the first diode 810, causing the first diode 810 to be in an off state. This off state of the first diode 810 disconnects the first absorption sub-circuit 820 from the CC pin 4102, rendering the first absorption sub-circuit 820 inoperable and thereby rendering the first protection circuit 620 inoperative.

[0105] During the charging process described above, when CC pin 4102 is short-circuited with VBUS pin 4101, CC pin 4102 is subjected to a surge voltage. Therefore, the voltage at the anode of first diode 810 is the surge voltage. The voltage at the cathode of first diode 810 is substantially equal to the voltage of power supply 220. Because the surge voltage is greater than the voltage of power supply 220, the difference between the surge voltage and the voltage of power supply 220 is greater than a preset voltage, and the difference between the voltages at the anode and cathode of first diode 810 is greater than the preset voltage, first diode 810 is in a conductive state. The conductive state of first diode 810 connects first absorption sub-circuit 820 to CC pin 4102, enabling operation of first absorption sub-circuit 820 and thus enabling operation of first protection circuit 620. When the first absorption sub-circuit 820 is operating, it can suppress the surge acting on the CC pin 4102, thereby clamping the voltage on the CC pin 4102 of the Type-C interface 410 within a safe voltage value range. It can slow down the voltage ringing on the CC pin 4102 of the Type-C interface 410, and prevent the functional chip 230 from being burned due to a sudden voltage increase or an internal latch-up effect caused by an excessive surge voltage slope.

[0106] It should be noted that, in combination with B in FIG. 2 and FIG. 8 , it can be seen that the second end of the first absorption sub-circuit 820 can be coupled to the second pole of the first switching element 2201 in the power supply 220 .

[0107] The first absorption sub-circuit 820 may include at least one electronic component selected from the group consisting of a resistor and a capacitor. Parameters such as the number of resistors and capacitors, the resistance values ​​of the resistors, and the capacitance values ​​of the capacitors are related to the aforementioned surge parameters. In the present embodiment, the first absorption sub-circuit is illustrated as including one resistor and / or one capacitor. This is described in detail below with reference to Figures 9 and 10.

[0108] In one embodiment, the first absorption sub-circuit 820 may include both a resistor and a capacitor. That is, the first absorption sub-circuit 820 may be a resistor-capacitor (RC) circuit. Depending on the arrangement of the resistor and capacitor, RC circuits can be classified as either series or parallel RC circuits.

[0109] FIG9 shows a second structural diagram of an interface protection circuit provided in an embodiment of the present application.

[0110] For example, in conjunction with FIG8 , as shown in FIG9A , the first absorption sub-circuit 820 may be an RC parallel circuit, wherein a first resistor R1 is connected in parallel with a first capacitor C1 , a first end of the first resistor R1 is coupled to the cathode of the first diode 810 , and a second end of the first resistor R1 is coupled to the power supply terminal of the power supply 220 .

[0111] For example, in conjunction with FIG8 , as shown in FIG9B , the first absorption sub-circuit 820 may be an RC series circuit, wherein a first end of the first resistor R1 is coupled to the cathode of the first diode 810 , a second end of the first resistor R1 is coupled to a first end of the first capacitor C1 , and a second end of the first capacitor C1 is coupled to a power supply terminal of the power supply 220 .

[0112] When the first diode 810 is turned on, the RC parallel circuit or the RC series circuit can suppress the surge acting on the CC pin 4102, thereby clamping the voltage on the CC pin 4102 within a safe voltage value range, which can slow down the voltage ringing on the CC pin 4102 and prevent the functional chip from being burned due to a sudden voltage increase or an internal latch-up effect caused by an excessive surge voltage slope.

[0113] Specifically, when the first diode 810 is turned on, in the RC parallel circuit or the RC series circuit, the energy storage function of the first capacitor is used to suppress surges, and the first resistor can limit the current when the first capacitor is charged and discharged.

[0114] FIG10 shows a third structural diagram of an interface protection circuit provided in an embodiment of the present application.

[0115] In another embodiment, as shown in FIG10A in conjunction with FIG8 , the first absorption sub-circuit 820 may include only a resistor, wherein a first end of the first resistor R1 is coupled to the cathode of the first diode 810 , and a second end of the first resistor R1 is coupled to the power supply terminal of the power supply 220 .

[0116] Specifically, when the first diode 810 is turned on, the first resistor R1 can limit the current, converting electrical energy into heat and dissipating it, thereby clamping the voltage on the CC pin 4102 within a safe voltage range. This can reduce voltage ringing on the CC pin 4102 and prevent the functional chip from burning out due to a sudden voltage surge or an internal latch-up effect caused by a surge voltage with an excessive slope. This suppression method is simpler and less costly.

[0117] In another embodiment, as shown in FIG10B in conjunction with FIG8 , the first absorption sub-circuit 820 may include only a capacitor, wherein a first end of the first capacitor C1 is coupled to the cathode of the first diode 810 , and a second end of the first resistor R1 is coupled to the power supply terminal of the power supply 220 .

[0118] Specifically, when the first diode 810 is turned on, the first capacitor C1 receives a surge and rapidly charges or discharges, thereby suppressing the surge acting on the CC pin 4102 and clamping the voltage on the CC pin 4102 within a safe voltage range. This can reduce voltage ringing on the CC pin 4102 and prevent the functional chip from burning out due to a sudden voltage surge or an internal latch-up effect caused by an excessively steep surge voltage slope. This suppression method is simpler and less costly.

[0119] FIG11 shows a second schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application.

[0120] Optionally, as shown in FIG11 , the electronic device 600 provided in the embodiment of the present application may further include a second absorption subcircuit 1110. The second absorption subcircuit 1110 may be coupled to the path between the VBUS pin 4101 of the Type-C interface 410 and the power supply 220.

[0121] In this embodiment, the interface protection circuit may include a second protection circuit 630. The second protection circuit 630 may include a second diode 1120. The anode of the second diode 1120 is coupled to the CC pin 4102 of the Type-C interface 410 and the output terminal of the function chip 230. The cathode of the second diode 1120 is coupled to the VBUS pin 4101 of the Type-C interface 410.

[0122] 4 and 11 , the cathode of the second diode 1120 can be coupled to the VBUS pin 4101, and the first end of the second switch element 430 (i.e., the first end of the NMOS) can be coupled to the VBUS pin 4101. In other words, the cathode of the second diode 1120 can be directly coupled to the VBUS pin 4101. Alternatively, the cathode of the second diode 1120 can be coupled to the second end of the second switch element 430 (i.e., the second end of the NMOS), and the first end of the second switch element 430 can be coupled to the VBUS pin 4101. In other words, the cathode of the second diode 1120 can be coupled to the VBUS pin 4101 through the second switch element 430.

[0123] During the aforementioned charging process, when CC pin 4102 and VBUS pin 4101 are not short-circuited, the aforementioned circuit structure shows that the voltage at the anode of second diode 1120 is equal to the voltage at CC pin 4102. Since the voltage at CC pin 4102 is lower than the voltage at power supply 220, the voltage at the anode of second diode 1120 is lower than the voltage at power supply 220. Furthermore, the voltage at the cathode of second diode 1120 is equal to the voltage at VBUS pin 4101. Typically, the voltage at VBUS pin 4101 is substantially equal to the voltage at power supply 220. Therefore, during the aforementioned charging process, when CC pin 4102 and VBUS pin 4101 are not short-circuited, the voltage at the anode of second diode 1120 is lower than the voltage at the cathode of second diode 1120, causing second diode 1120 to be in an off state. Since second diode 1120 is in an off state, interface protection circuit 610 does not operate. At the same time, the second diode 1120 is in the cut-off state, so that the second absorption sub-circuit 1110 is disconnected from the CC pin 4102 . Therefore, the second absorption sub-circuit 1110 does not suppress the voltage on the CC pin 4102 .

[0124] During the charging process described above, when CC pin 4102 is short-circuited with VBUS pin 4101 and CC pin 4102, CC pin 4102 is subjected to a surge voltage. Therefore, the voltage at the anode of second diode 1120 is the surge voltage. The voltage at the cathode of second diode 1120 is the voltage at VBUS pin 4101. The surge voltage is greater than the voltage at VBUS pin 4101, and the difference between the surge voltage and the voltage at VBUS pin 4101 is greater than a preset voltage. Therefore, when CC pin 4102 is short-circuited with VBUS pin 4101, the voltage at the anode of second diode 1120 is greater than the voltage at the cathode of second diode 1120, and the difference between the voltages at the anode and cathode of second diode 1120 is greater than a preset voltage, causing second diode 1120 to be in a conductive state. The second diode 1120 is in the on state, so that the second absorption sub-circuit 1110 is connected to the CC pin 4102. In this way, the second absorption sub-circuit 1110 can suppress the surge acting on the CC pin 4102, thereby clamping the voltage on the CC pin 4102 of the Type-C interface 410 within a safe voltage value range. This can slow down the voltage ringing on the CC pin 4102 of the Type-C interface 410, and prevent the functional chip 230 from being burned due to a sudden voltage increase or an internal latch-up effect caused by an excessive surge voltage slope.

[0125] The second absorption sub-circuit 1110 may include only capacitors, or may include both capacitors and resistors. Parameters such as the number of resistors and capacitors, the resistance values ​​of the resistors, and the capacitance values ​​of the capacitors are related to the aforementioned surge parameters. In the present embodiment, the second absorption sub-circuit includes one resistor and / or one capacitor. This is described in detail below with reference to FIG12.

[0126] In one embodiment, the second absorption sub-circuit 1110 may include both a resistor and a capacitor. That is, the second absorption sub-circuit 1110 may be a resistor-capacitor (RC) circuit. Depending on the arrangement of the resistor and capacitor, RC circuits can be classified as either series or parallel RC circuits.

[0127] FIG12 shows a third schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application.

[0128] For example, with reference to FIG11 , as shown in FIG12A , the second absorption sub-circuit 1110 may be an RC parallel circuit, wherein a second resistor R2 is connected in parallel with a second capacitor C2, a first end of the second resistor R2 is coupled to the cathode of the second diode 1120, and a second end of the second resistor R2 is coupled to the ground of the electronic device 600.

[0129] For example, with reference to FIG11 , as shown in FIG12B , the second absorption sub-circuit 1110 may be an RC series circuit, wherein a first end of the second resistor R2 is coupled to the cathode of the second diode 1120 , a second end of the second resistor R2 is coupled to a first end of the second capacitor C2 , and a second end of the second capacitor C2 is coupled to the ground of the electronic device 600 .

[0130] When the second diode 1120 is turned on, the RC parallel circuit or the RC series circuit can suppress the surge on the CC pin 4102, thereby clamping the voltage on the CC pin 4102 within a safe voltage value range, slowing down the voltage ringing on the CC pin 4102, and preventing the functional chip from being burned due to a sudden voltage increase or an internal latch-up effect caused by an excessive surge voltage slope.

[0131] Specifically, when the second diode 1120 is turned on, in the RC parallel circuit or the RC series circuit, the energy storage function of the second capacitor is used to suppress the surge acting on the CC pin 4102, and the second resistor can limit the current when the second capacitor is charged and discharged.

[0132] In another embodiment, as shown in C in FIG12 , in conjunction with FIG11 , the second absorption subcircuit 1110 may include a second capacitor C2. A first end of the second capacitor C2 is coupled to the cathode of the second diode 1120, and a second end of the second capacitor C2 is coupled to the ground of the electronic device 600.

[0133] Specifically, when the second diode 1120 is turned on, the second capacitor C2 receives a surge and rapidly charges or discharges, thereby suppressing the surge acting on the CC pin 4102 and clamping the voltage on the CC pin 4102 within a safe voltage range. This can reduce voltage ringing on the CC pin 4102 and prevent the functional chip from burning out due to a sudden voltage surge or an internal latch-up effect caused by an excessively large surge voltage slope. This suppression method is simpler and less costly.

[0134] FIG13 shows a fourth schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application.

[0135] In some embodiments, as shown in FIG13 , the electronic device 600 includes a second absorption sub-circuit 1110, and the interface protection circuit may include both a first protection circuit 620 and a second protection circuit 630. The first protection circuit 620 may include a first diode 810 and a first absorption sub-circuit 820, and the second protection circuit 630 may include a second diode 1120. The connection relationship between the first diode 810, the first absorption sub-circuit 820, the second diode 1120, and the second absorption sub-circuit 1110 in the electronic device 600, as well as the structures of the first absorption sub-circuit 820 and the second absorption sub-circuit 1110, can be found in the description of the above embodiments and will not be further elaborated in this embodiment.

[0136] In summary, in the electronic device provided by the embodiments of the present application, the interface protection circuit located between the Type-C interface and the functional chip can suppress surges acting on the CC pin of the Type-C interface, thereby clamping the voltage on the CC pin of the Type-C interface within a safe voltage range. This can reduce voltage ringing on the CC pin of the Type-C interface and prevent the functional chip from burning due to a sudden voltage surge or an internal latch-up effect caused by an excessive surge voltage slope. At the same time, the interface protection circuit does not affect the function of the CC pin of the Type-C interface.

[0137] In addition, the interface protection circuit provided in the embodiment of the present application is composed of simple electronic components. Therefore, the interface protection circuit provided in the embodiment of the present application has a simple structure and low cost, which reduces the production cost of the electronic equipment.

[0138] In the several embodiments provided in this application, it should be understood that the disclosed circuits and devices can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules is merely a logical function division. In actual implementation, there may be other division methods, such as multiple modules or components can be combined or integrated into another device, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interface, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0139] The modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical modules, that is, they may be located on a single device or distributed across multiple devices. Some or all of the modules may be selected to achieve the purpose of this embodiment based on actual needs.

[0140] In addition, the functional modules in the various embodiments of the present application may be integrated into one device, or each module may exist physically separately, or two or more modules may be integrated into one device.

[0141] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An interface protection circuit, characterized in that: Applicable to an electronic device, the electronic device comprises a function chip and a Type-C interface, the Type-C interface comprises a CC pin and a VBUS pin, the CC pin is coupled to the function chip; The interface protection circuit includes: a first protection circuit and / or a second protection circuit; wherein, The first end of the first protection circuit is coupled to the CC pin, and the second end of the first protection circuit is coupled to the power supply of the electronic device; when the difference between the voltage at the first end of the first protection circuit and the voltage at the second end of the first protection circuit is greater than a preset voltage, and the voltage at the first end of the first protection circuit is greater than the voltage at the second end of the first protection circuit, the first protection circuit works to suppress the surge on the CC pin; The first end of the second protection circuit is coupled to the CC pin, and the second end of the second protection circuit is coupled to the VBUS pin; when the difference between the voltage at the first end of the second protection circuit and the voltage at the second end of the second protection circuit is greater than a preset voltage, and the voltage at the first end of the second protection circuit is greater than the voltage at the second end of the second protection circuit, the second protection circuit operates to enable the electronic device to suppress surges on the CC pin.

2. The circuit according to claim 1, characterized in that The first protection circuit in the interface protection circuit comprises: a first diode and a first absorption subcircuit; The anode of the first diode is coupled to the CC pin of the Type-C interface, the cathode of the first diode is coupled to the first end of the first absorption sub-circuit, and the second end of the first absorption sub-circuit is coupled to the power supply.

3. The circuit according to claim 2, characterized in that The first absorption subcircuit includes a first resistor; a first end of the first resistor is coupled to the cathode of the first diode, and a second end of the first resistor is coupled to the power supply.

4. The circuit according to claim 2, characterized in that The first absorption subcircuit includes a first capacitor; a first end of the first capacitor is coupled to the cathode of the first diode, and a second end of the first capacitor is coupled to the power supply.

5. The circuit according to claim 2, characterized in that The first absorption subcircuit includes a first resistor and a first capacitor; the first resistor and the first capacitor are connected in parallel or in series; the cathode of the first diode is coupled to the power supply through the first resistor and the first capacitor.

6. The circuit according to any one of claims 1 to 5, characterized in that: The electronic device includes a second absorption subcircuit, the second absorption subcircuit is coupled to the VBUS pin; The second protection circuit in the interface protection circuit includes a second diode; the anode of the second diode is coupled to the CC pin, and the cathode of the second diode is coupled to the VBUS pin of the Type-C interface.

7. The circuit according to claim 6, characterized in that The second absorption subcircuit includes a second capacitor; a first end of the second capacitor is coupled to the cathode of the second diode, and a second end of the second capacitor is coupled to the ground terminal of the electronic device.

8. The circuit according to claim 6, characterized in that The second absorption subcircuit includes a second resistor and a second capacitor, the second resistor and the second capacitor are connected in series; the first end of the second resistor and the second capacitor connected in series is coupled to the cathode of the second diode, and the second end of the second resistor and the second capacitor connected in series is coupled to the ground terminal of the electronic device.

9. The circuit according to claim 6, characterized in that The second absorption subcircuit includes a second resistor and a second capacitor; the second resistor is connected in parallel with the second capacitor; the first ends of the second resistor and the second capacitor connected in parallel are coupled to the cathode of the second diode, and the second ends of the second resistor and the second capacitor connected in parallel are coupled to the ground terminal of the electronic device.

10. An electronic device, characterized in that: include: A power supply, a functional chip, a second absorption sub-circuit, a Type-C interface, and an interface protection circuit according to any one of claims 1 to 9; wherein the Type-C interface comprises a CC pin and a VBUS pin, and the CC pin is coupled to the functional chip; the interface protection circuit comprises a first protection circuit and / or a second protection circuit; A first end of the first protection circuit is coupled to the CC pin, and a second end of the first protection circuit is coupled to a power supply of the electronic device; A first terminal of the second protection circuit is coupled to the CC pin, and a second terminal of the second protection circuit is coupled to the VBUS pin.

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