HDMI interface protection device and equipment

Abstract

The utility model relates to an interface protection technology, in particular to an HDM I interface protection device and equipment. The device comprises a signal receiving port and a signal output port, and at least one type of signal protection path is arranged between the signal receiving port and the signal output port. The signal protection path is integrated on the circuit board in the form of a circuit. The signal protection path comprises a receiving end protection path, a re-timer chip and an output end protection path, so that at least two stages of protection devices are provided for surge protection, the surge resistance of the HDM I interface is greatly improved, the HDM I interface can normally work in a relatively severe use environment, the stability and reliability of signal transmission are ensured, and the service life of the HDM I interface is prolonged. In the scheme, a re-timer chip is arranged between two stages of protection paths, so that the influence of the increase of the number of protection devices on the transmission signal is reduced, the influence of jitter or distortion possibly generated in the signal transmission process is eliminated, and the signal output by the signal output port can be ensured to keep high quality and integrity.

Description

Technical Field

[0001] The present application relates to interface protection technology, and in particular to an HDMI interface protection device and equipment. Background Art

[0002] The HDMI interface (High-Definition Multimedia Interface) is a fully digital video and audio transmission interface that is widely used between various electronic devices to transmit high-definition video and audio signals. However, the use of the HDMI interface is easily affected in some relatively harsh environments. For example, in the laser industry, laser equipment usually operates in an environment with high voltage, high current or high electromagnetic radiation, which has a great impact on the HDMI interface and can easily cause damage to the HDMI interface; for example, in a factory environment, especially in an automated production line that requires high-precision display or remote monitoring, the electrical interference, electrostatic discharge and surge current in the production environment also have a serious impact on the HDMI interface.

[0003] Currently, the main protection design for HDMI interfaces is to connect an ESD protection chip to the interface. However, this method does not provide sufficient surge protection in the relatively harsh usage scenarios mentioned above, and the HDMI interface is easily damaged by environmental interference. Utility Model Content

[0004] The embodiments of the present application mainly solve the technical problem that the existing protection solutions have poor protection effects on HDMI interfaces in harsh environments.

[0005] In order to solve the above technical problems, a technical solution adopted in the embodiment of the present application is: providing an HDMI interface protection device, including a signal receiving port and a signal output port, at least one type of signal protection path is set between the signal receiving port and the signal output port, the signal protection path is integrated into the circuit board in the form of a circuit, the signal protection path includes a receiving end protection path, a retimer chip and an output end protection path; the signal receiving port is used to receive the signal to be transmitted, and transmit the signal to be transmitted to the retimer chip through the receiving end protection path; the receiving end protection path is used to provide surge protection for the signal to be transmitted; the retimer chip is used to enhance the signal to be transmitted, and transmit the enhanced signal to be transmitted to the signal output port through the output end protection path, so that the signal output port outputs the enhanced signal to be transmitted; the output end protection path is used to provide surge protection for the enhanced signal to be transmitted.

[0006] The HDMI interface protection device provided by this solution has protection paths set up at both the signal receiving end and the signal output end. That is, the receiving end protection path and the output end protection path provide at least two levels of protection devices for surge protection, which greatly improves the surge resistance of the HDMI interface, enabling the HDMI interface to effectively resist the impact of electrical interference on the signal, protect the interface circuit from damage, and enable it to operate normally even in relatively harsh usage environments, ensuring the stability and reliability of signal transmission. At the same time, this solution also sets up a retimer chip between the two-level protection paths to reduce the impact of the increase in the number of components on the transmitted signal, eliminate the effects of jitter or distortion that may occur in the signal during transmission, and resynchronize and reshape the signal to ensure that the signal output from the signal output port can maintain high quality and integrity.

[0007] In some embodiments, at least one type of signal protection path includes a hot-swap HPD signal protection path, wherein: the receiving end protection device in the HPD signal protection path includes a first fuse, a first transient suppression diode and a first current limiting resistor, and the working circuit of the first fuse, the working circuit of the first transient suppression diode and the working circuit of the first current limiting resistor are connected in series in sequence to provide a transmission line for the HPD signal; the output end protection device in the HPD signal protection path includes a surge suppression thyristor, a second fuse, a second current limiting resistor, a second transient suppression diode and a third current limiting resistor, and the working circuit of the surge suppression thyristor, the working circuit of the second fuse, the working circuit of the second current limiting resistor, the working circuit of the second transient suppression diode and the working circuit of the third current limiting resistor are connected in series in sequence to provide an enhanced transmission line for the HPD signal.

[0008] The HPD signal is an important signal in the HDMI interface that detects whether the display device is ready to receive signals. Its corresponding signal protection path is equipped with working circuits of multiple protection devices such as transient suppression diodes, current limiting resistors, fuses, surge suppression thyristors, etc., which provide corresponding surge protection for the transmission line of the HPD signal, effectively reducing the impact of external electrical interference or internal faults on the HPD signal, thereby enhancing the stability and reliability of the HPD signal.

[0009] In some embodiments, at least one type of signal protection path includes a minimized transmission differential signal (TMDS) signal protection path, wherein: the receiving-end protection device in the TMDS signal protection path includes a first fuse, a first transient suppression diode, a first current-limiting resistor, and a first common-mode inductor, and the working circuit of the first fuse, the working circuit of the first transient suppression diode, the working circuit of the first current-limiting resistor, and the working circuit of the first common-mode inductor are connected in series in sequence to provide a transmission line for the TMDS signal; the output-end protection device in the TMDS signal protection path includes a surge suppression thyristor, a second fuse, a second current-limiting resistor, a second transient suppression diode, a second common-mode inductor, and a third current-limiting resistor, and the working circuit of the surge suppression thyristor, the working circuit of the second fuse, the working circuit of the second current-limiting resistor, the working circuit of the second transient suppression diode, the working circuit of the second common-mode inductor, and the working circuit of the third current-limiting resistor are connected in series in sequence to provide an enhanced TMDS signal transmission line.

[0010] TMDS signals are important video transmission signals in the HDMI interface. Their stability often directly affects the audio and video quality. Therefore, in addition to setting up conventional protection devices such as transient suppression diodes, current-limiting resistors, fuses, and surge suppression thyristors, this solution sets up a common-mode inductor working circuit in its signal protection path for TMDS signals. The common-mode inductor is used to filter out noise components in the signal, reduce signal distortion and attenuation, further enhance the anti-interference ability of the TMDS signal, and ensure high-quality transmission of video signals.

[0011] In some embodiments, at least one type of signal protection path includes a display data channel DDC signal protection path, wherein: the receiving end protection device in the DDC signal protection path includes a first fuse, a first transient suppression diode, a first current limiting resistor and a first MOS transistor, and the working circuit of the first fuse, the working circuit of the first transient suppression diode, the working circuit of the first current limiting resistor and the working circuit of the first MOS transistor are connected in series in sequence to provide a transmission line for the DDC signal; the output end protection device in the DDC signal protection path includes a surge suppression thyristor, a second fuse, a second current limiting resistor, a second transient suppression diode and a second MOS transistor, and the working circuit of the surge suppression thyristor, the working circuit of the second fuse, the working circuit of the second current limiting resistor, the working circuit of the second transient suppression diode and the working circuit of the second MOS transistor are connected in series in sequence to provide a transmission line for the enhanced DDC signal.

[0012] The DDC signal is a channel signal used by the display and video source devices in the HDMI interface to exchange configuration information. Therefore, in addition to conventional protective devices such as transient suppression diodes, current-limiting resistors, fuses, and surge suppression thyristors, this solution sets up a MOS tube working circuit for the DDC signal transmission line to provide a level conversion function. This allows different devices to support compatible DDC signal levels, avoids communication failures or data errors caused by level mismatch, and optimizes signal transmission quality.

[0013] In some embodiments, the circuit board also integrates a power protection path circuit, which is used to provide surge protection for the power supply signal. The power protection path includes a receiving-end power path and an output-end power path. The signal receiving port is connected to the internal power supply via the receiving-end power path, and the internal power supply is connected to the signal output port via the output-end power path. The internal power supply is used to power the retimer chip. This solution can provide surge protection for the power supply signal transmission line. If a surge voltage occurs in the external power supply connected to the HDMI interface, this setting can quickly respond and suppress this surge voltage, protecting the internal circuit from damage. For example, it can ensure the normal power supply of the retimer chip and improve the device's surge resistance.

[0014] In some embodiments, the receiving end power path includes the working circuit of the third fuse, the working circuit of the third transient suppression diode, the working circuit of the first magnetic bead and the working circuit of the diode. The working circuit of the third fuse, the working circuit of the third transient suppression diode, the working circuit of the first magnetic bead and the working circuit of the diode are connected in series in sequence to provide a transmission line for the power supply signal; the output end power path includes the working circuit of the fourth fuse, the working circuit of the fifth transient suppression diode, the working circuit of the second magnetic bead and the working circuit of the fourth transient suppression diode. The working circuit of the fourth fuse, the working circuit of the fifth transient suppression diode, the working circuit of the second magnetic bead and the working circuit of the fourth transient suppression diode are connected in series in sequence to provide a transmission line for the power supply signal of the internal power supply.

[0015] This solution implements multiple protections for the power supply signal by setting up working circuits of multiple protection devices such as fuses, ferrite beads, and transient suppression diodes in the receiving-end power path and the output-end power path. This can effectively resist various forms of power supply interference and surge impacts, ensuring the stability and safety of the power supply signal.

[0016] In some embodiments, the receiving-end protection path includes the working circuits of at least two receiving-end protection devices, which are connected in series to provide a transmission path for the signal to be transmitted; and the output-end protection path includes the working circuits of at least two output-end protection devices, which are connected in series to provide an enhanced transmission path for the signal to be transmitted. This solution significantly enhances the device's surge resistance by providing signal protection paths at both the receiving and output ends. The receiving-end protection devices and the output-end protection devices together form a multi-layered protection system that can effectively resist electrical anomalies such as overcurrent, overvoltage, transient voltage shocks, and surges, thereby improving the device's reliability.

[0017] In some embodiments, a bypass circuit is further provided between the receiving end protection path and the output end protection path, and the bypass circuit is used to provide a transmission line for the signal to be transmitted from the signal receiving port to the signal output port, so that the transmission of the signal to be transmitted does not pass through the retimer chip.

[0018] By setting up a bypass circuit, this solution can provide a signal transmission line that does not pass through the chip when the chip is overloaded, fails, or needs to reduce delay, thereby improving the fault tolerance of the device.

[0019] Another technical solution adopted in the embodiment of the present application is an HDMI interface protection device, which includes a box body and the above-mentioned HDMI interface protection device. The box body is made of conductive material, the signal receiving port is set at one end of the box body, the signal output port is set at the other end of the box body, and the circuit board is set inside the box body; an isolation capacitor is set between the casing ground of the box body and the internal ground of the circuit board.

[0020] This solution uses the box to form an electromagnetic shield, reducing the impact of external electromagnetic interference on the internal circuits. At the same time, by providing isolation capacitors, the chassis ground and internal ground are electrically isolated, reducing the impact of static electricity from the box on the internal circuits and improving equipment safety.

[0021] In some embodiments, a grounding screw is provided on the outside of the box body to provide a grounding circuit for the box body. This solution provides a means of eliminating static electricity in the box body through the provision of the grounding screw, further improving the reliability and stability of the device.

[0022] Different from the related art, the embodiment of the present application provides an HDMI interface protection device and equipment. The device includes a signal receiving port and a signal output port. At least one type of signal protection path is set between the signal receiving port and the signal output port. The signal protection path is integrated into the circuit board in the form of a circuit. The signal protection path includes a receiving end protection path, a retimer chip and an output end protection path. This solution sets a working circuit composed of multiple protection devices as a protection path at both the signal receiving end and the signal output end, that is, the receiving end protection path and the output end protection path provide at least two levels of protection devices for surge protection, which greatly improves the surge resistance of the HDMI interface, so that the HDMI interface can effectively resist the impact of electrical interference on the signal, protect the interface circuit from being damaged, and enable it to work normally in a relatively harsh use environment, ensuring the stability and reliability of signal transmission. At the same time, this solution also sets a retimer chip between the two levels of protection paths to reduce the influence of parasitic capacitance on the transmitted signal, eliminate the influence of jitter or distortion that may occur in the signal during transmission, and can also resynchronize and reshape the signal to ensure that the signal output from the signal output port can maintain high quality and integrity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural block diagram of an HDMI interface protection device provided in an embodiment of the present application;

[0024] Figure 2 This is a schematic diagram of the structure of an HPD signal protection path provided by an embodiment of the present application;

[0025] Figure 3 This is a structural diagram of a TMDS signal protection path provided by an embodiment of the present application;

[0026] Figure 4 This is a structural diagram of a DDC signal protection path provided by an embodiment of the present application;

[0027] Figures 5a-5g 1 is a circuit diagram of a signal protection path provided in an embodiment of the present application;

[0028] Figure 6 This is a structural block diagram of another HDMI interface protection device provided in an embodiment of the present application;

[0029] Figure 7 This is a schematic diagram of the structure of a power protection path provided by an embodiment of the present application;

[0030] Figures 8a-8b This is a circuit diagram of a power protection path provided by an embodiment of the present application;

[0031] Figure 9This is a structural block diagram of a bypass circuit provided in an embodiment of the present application;

[0032] Figures 10a-10c is a circuit diagram of a bypass circuit provided in an embodiment of the present application;

[0033] Figure 11 This is a schematic diagram of a working circuit of an isolation capacitor provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to facilitate the understanding of the present application, the present application is described in more detail below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as "connected" to another element, it can be directly connected to the other element, or there can be one or more centered elements therebetween. The terms "inside", "outside", etc. used in this specification indicate an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0035] Unless otherwise defined, all technical and scientific terms used in this specification have the same meanings as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification and in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" as used in this specification includes any and all combinations of one or more of the relevant listed items.

[0036] The HDMI interface is a fully digital video and audio transmission interface widely used in various electronic devices (such as TVs, computer monitors, projectors, game consoles, Blu-ray players, etc.). It is known for its high-quality video and audio transmission capabilities, supporting multi-channel audio and high-definition video content, which can greatly enhance the user experience.

[0037] However, the inventors discovered during use that electrical interference caused by the environment, such as surge voltage or electrostatic discharge, has a great impact on the HDMI interface. The current protection method for the HDMI interface is simply to set an ESD protection chip (such as the ESD0524 device) in the interface circuit. Although this design can meet most conventional usage scenarios, it is not very effective in protecting the interface in some relatively harsh usage scenarios. For example, in the laser industry, laser equipment usually operates in an environment with high voltage, high current or high electromagnetic radiation, which has a great impact on the HDMI interface and can easily cause damage to the HDMI interface; for example, in a factory environment, especially in an automated production line that requires high-precision display or remote monitoring, the electrical interference, electrostatic discharge and surge current in the production environment also have a serious impact on the HDMI interface. For these special usage scenarios, it is not uncommon for the interface circuit to be damaged (such as the ESD protection chip to burn out) or even the host to be damaged due to environmental influences. The existing protection design is obviously not enough to meet the surge resistance requirements of the interface.

[0038] In response to the above technical problems, the present application creatively proposes a new technical solution to improve the surge protection effect of the HDMI interface in terms of surge protection and signal quality.

[0039] First, for surge protection, an interface protection device is designed for the HDMI interface to provide a surge protection circuit for the signal transmission line. A surge protection structure is designed in the form of multi-level protection. A receiving end protection path is designed at the signal receiving port of the device, and an output end protection path is designed at the signal output port. At least two levels of protection paths are designed for the transmission line with the transmission signal to improve the surge resistance of the HDMI interface.

[0040] Secondly, in terms of signal quality, a retimer is designed in the signal transmission line to enhance the signal and ensure that the signal maintains high quality and integrity at the signal output port.

[0041] This embodiment, through the above-mentioned innovative solution, can improve the surge resistance of the interface and ensure signal quality.

[0042] Based on the above technical concept, this embodiment is further explained in combination with specific scenarios.

[0043] Figure 1 This is a schematic structural block diagram of an HDMI interface protection device provided in an embodiment of the present application.

[0044] like Figure 1 As shown, the device includes a signal receiving port 11, a signal output disconnect 12, and at least one type of signal protection path 13 arranged therebetween.

[0045] The signal protection path 13 is integrated into the circuit board in the form of a circuit in combination with the signal receiving port 11 and the signal output port 12. The signal receiving port 11 corresponds to the input end of the circuit, and the signal output port 12 corresponds to the output end of the circuit. The signal protection path is the transmission line for the signal to be transmitted.

[0046] The signal protection path 13 includes a receiving end protection path 131 , an output end protection path 132 , and a retimer chip 133 disposed therebetween.

[0047] Specifically, the signal receiving port 11 receives the signal to be transmitted, and transmits the signal to be transmitted to the retimer chip 133 through the receiving end protection path 131. The receiving end protection path 131 provides surge protection for the signal to be transmitted and suppresses surge voltage. The retimer chip 133 retimes and redrives the signal to be transmitted, enhances the signal to be transmitted, and transmits the enhanced signal to be transmitted to the signal output port 12 through the output end protection path 132. The output end protection path 132 provides surge protection for the enhanced signal to be transmitted, and the signal output port 12 outputs the enhanced signal to be transmitted.

[0048] The HDMI interface protection device provided by this solution has protection paths composed of working circuits of protection devices at both the signal receiving end and the signal output end. That is, the receiving end protection path and the output end protection path provide at least two levels of protection devices for surge protection, protecting the internal circuits of the interface from damage, greatly improving the surge resistance of the HDMI interface, enabling the HDMI interface to effectively resist the impact of electrical interference on the signal, and operate normally even in relatively harsh usage environments, ensuring the stability and reliability of signal transmission. At the same time, this solution also sets a retimer chip between the two levels of protection paths to reduce the impact of the increased number of devices on signal quality, eliminate the effects of jitter or distortion that may occur during signal transmission, and resynchronize and reshape the signal to ensure that the signal output from the signal output port can maintain high quality and integrity.

[0049] In an embodiment of the present application, the above-mentioned receiving-end protection path includes the working circuits of at least two receiving-end protection devices, and the working circuits of at least two receiving-end protection devices are connected in series to provide a transmission line for the signal to be transmitted; the above-mentioned output-end protection path includes the working circuits of at least two output-end protection devices, and the working circuits of at least two output-end protection devices are connected in series to provide an enhanced transmission line for the signal to be transmitted. This solution significantly enhances the surge resistance of the device by setting corresponding signal protection paths at the receiving end and the output end respectively, wherein the working circuits of the receiving-end protection device and the output-end protection device together constitute a two-level protection system, which can effectively resist the effects of electrical abnormalities such as overcurrent, overvoltage, transient voltage shocks and surges, thereby improving the reliability of the device.

[0050] The signals supported for transmission by the HDMI interface may include an HPD signal. The HPD signal is an important signal in the HDMI interface for detecting whether the display device is ready to receive signals. In an embodiment of the present application, an HPD signal protection path is set for the HPD signal, wherein the receiving end protection device in the receiving end protection path of the HPD signal protection path includes a first fuse, a first transient voltage suppressor (TVS) and a first current limiting resistor; the output end protection device in the output end protection path of the HPD signal protection path includes a surge suppression thyristor (TSS), a second fuse, a second current limiting resistor, a second transient voltage suppressor (TVS) and a third current limiting resistor.

[0051] For explanatory purposes, see Figure 2 , explained with the help of the structural block diagram example of the HPD signal protection path.

[0052] Figure 2 The first fuse shown represents the working circuit of the first fuse, the first TVS represents the working circuit of the first transient suppression diode, the first current limiting resistor represents the working circuit of the first current limiting resistor; TSS represents the working circuit of the surge suppression thyristor, the second fuse represents the working circuit of the second fuse, the second current limiting resistor represents the working circuit of the second current limiting resistor, the second TVS represents the working circuit of the second transient suppression diode, and the third current limiting resistor represents the working circuit of the third current limiting resistor. Figure 2 As shown, the signal receiving port is electrically connected to the working circuit of the first fuse, the working circuit of the first transient suppression diode, and the working circuit of the first current-limiting resistor in sequence, and then connected to the retimer chip, thereby providing a transmission line for the HPD signal; the retimer chip amplifies the HDP signal, and the output end of the retimer chip is electrically connected to the working circuit of the third current-limiting resistor, the working circuit of the second transient suppression diode, the working circuit of the second current-limiting resistor, the working circuit of the second fuse, and the working circuit of the surge suppression thyristor in sequence, and then connected to the signal output port, thereby providing a transmission line for the HPD signal amplified by the retimer chip.

[0053] like Figure 2As shown, the HPD signal enters the signal receiving port at one end of the device and is transmitted to the retimer chip via the receiving-end protection path. In the receiving-end protection path, the first fuse provides overcurrent protection, the first TVS acts as a protection device to suppress static electricity, EFT (Electrical Fast Transient), and surge voltage, and the first current-limiting resistor provides current limiting and voltage dividing to reduce interference voltage. The retimer chip can retime and redrive the HPD signal, offsetting attenuation and distortion during signal transmission and enhancing the signal quality. The enhanced HPD signal is then provided to the signal output port at the other end of the device via the output-end protection path. In the output-end protection path, the third current-limiting resistor provides current limiting protection, the second TVS also acts as a protection device to suppress static electricity, EFT, and surge voltage, the second current-limiting resistor provides current limiting and voltage dividing, the second fuse provides overcurrent protection for the circuit, and the TSS acts as a protection device to prevent large current surges from damaging the chip. Based on this, the HPD signal protection path can provide corresponding surge protection for the HPD signal transmission line, effectively reducing the impact of external electrical interference or internal faults on the HPD signal, thereby enhancing the stability and reliability of the HPD signal.

[0054] The signals supported for transmission by the HDMI interface may also include TMDS signals. The TMDS signal is an important video transmission signal in the HDMI interface, and its stability usually directly affects the audio and video effects. In the embodiment of the present application, a TMDS signal protection path is set for the TMDS signal, wherein the receiving end protection device in the TMDS signal protection path includes a first fuse, a first transient suppression diode, a first current limiting resistor and a first common-mode inductor; the output end protection device in the TMDS signal protection path includes a surge suppression thyristor, a second fuse, a second current limiting resistor, a second transient suppression diode, a second common-mode inductor and a third current limiting resistor. For the convenience of explanation, please refer to Figure 3 , explained with an example of a structural block diagram of a TMDS signal protection path.

[0055] Figure 3 The first fuse shown represents the working circuit of the first fuse, the first TVS represents the working circuit of the first transient suppression diode, the first common-mode inductor represents the working circuit of the first common-mode inductor, the first current limiting resistor represents the working circuit of the first current limiting resistor; the third current limiting resistor represents the working circuit of the third current limiting resistor, the second common-mode inductor represents the working circuit of the second common-mode inductor, the second TVS represents the working circuit of the second transient suppression diode, the second current limiting resistor represents the working circuit of the second current limiting resistor, the second fuse represents the working circuit of the second fuse, and the TSS represents the working circuit of the surge suppression thyristor.

[0056] like Figure 3 As shown, the signal receiving port is electrically connected to the working circuit of the first fuse, the working circuit of the first transient suppression diode, the working circuit of the first current limiting resistor, and the working circuit of the first common-mode inductor in sequence, and then connected to the retimer chip, thereby providing a transmission line for the TMDS signal; the retimer chip amplifies the TMDS signal, and the output end of the retimer chip is electrically connected to the working circuit of the third current limiting resistor, the working circuit of the second common-mode inductor, the working circuit of the second transient suppression diode, the working circuit of the second current limiting resistor, the working circuit of the second fuse, and the working circuit of the surge suppression thyristor in sequence, and then connected to the signal output port, thereby providing a transmission line for the TMDS signal amplified by the retimer chip.

[0057] like Figure 3 As shown, the TMDS signal enters the signal receiving port at one end of the device and is transmitted to the retimer chip via the receiving end protection path. In the receiving end protection path, the first fuse provides overcurrent protection; the first TVS acts as a protective device to suppress static electricity, EFT, and surge voltage; the first common-mode inductor is used to suppress common-mode interference. When a common-mode interference signal enters the circuit, the common-mode inductor generates an induced electromotive force on the common-mode inductor. This induced electromotive force forms a reverse current, which offsets the common-mode interference signal, thereby suppressing the propagation of the common-mode interference signal in the circuit; the first current-limiting resistor provides current limiting and voltage dividing, reducing the interference voltage. The retimer chip can retime and redrive the TMDS signal, offsetting the attenuation and distortion during signal transmission, and amplifying the signal to improve signal quality. The amplified signal is then provided to the signal output port at the other end of the device via the output end protection path. In the output protection path, the third current-limiting resistor provides current limiting protection. The second common-mode inductor, similar to the first common-mode inductor, can suppress common-mode interference. The second TVS, similar to the first TVS, acts as a protective device to suppress static electricity, EFT, and surge voltage. The second current-limiting resistor provides current limiting and voltage dividing. The second fuse provides overcurrent protection for the circuit. The TSS acts as a protective device to prevent high current surges from damaging the chip. Based on this, the TMDS signal protection path can provide corresponding surge protection for the TMDS signal transmission line, reducing the impact of external electrical interference or internal faults on the TMDS signal. The common-mode inductor also filters out noise components in the signal, reducing signal distortion and attenuation, further enhancing the TMDS signal's anti-interference capability and ensuring high-quality video signal transmission.

[0058] The signals supported by the HDMI interface may also include DDC signals. DDC signals are channel signals used by the display and video source device in the HDMI interface to exchange configuration information. Therefore, in the embodiments of the present application, the DDC signal protection path set for the DDC signal includes a MOS transistor to provide a level conversion function.

[0059] Specifically, the receiving end protection devices in the DDC signal protection path include a first fuse, a first transient suppression diode, a first current limiting resistor and a first MOS tube; the output end protection devices in the DDC signal protection path include a surge suppression thyristor, a second fuse, a second current limiting resistor, a second transient suppression diode and a second MOS tube.

[0060] For explanatory purposes, see Figure 4 , explained with the help of the structural block diagram example of the DDC signal protection path. Figure 4 The first fuse shown represents the working circuit of the first fuse, the first TVS represents the working circuit of the first transient suppression diode, the first current limiting resistor represents the working circuit of the first current limiting resistor, and the first MOS transistor represents the working circuit of the first MOS transistor; the second MOS transistor represents the working circuit of the second MOS transistor, the second TVS represents the working circuit of the second transient suppression diode, the second current limiting resistor represents the working circuit of the second current limiting resistor, the second fuse represents the working circuit of the second fuse, and the TSS represents the working circuit of the surge suppression thyristor.

[0061] like Figure 4 As shown, the signal receiving port is electrically connected to the working circuit of the first fuse, the working circuit of the first transient suppression diode, the working circuit of the first current-limiting resistor, and the working circuit of the first MOS tube in sequence, and then connected to the retimer chip, thereby providing a transmission line for the DDC signal; the retimer chip amplifies the DDC signal, and the output end of the retimer chip is electrically connected to the working circuit of the surge suppression thyristor, the working circuit of the second fuse, the working circuit of the second current-limiting resistor, the working circuit of the second transient suppression diode, and the working circuit of the second MOS tube in sequence, and then connected to the signal output port, thereby providing a transmission line for the DDC signal amplified by the retimer chip.

[0062] like Figure 4 As shown, in addition to providing signal protection functions by setting conventional protection devices such as transient suppression diodes, current limiting resistors, fuses, and surge suppression thyristors in the above-mentioned DDC signal protection path, a working circuit of a first MOS transistor and a second MOS transistor is also provided. Here, the first MOS transistor and the second MOS transistor are both level conversion MOS transistors, which are used to provide a function of converting signal levels. For example, a 5V signal can be converted into a 3.3V signal, so that the DDC signal levels supported by different devices are compatible with each other, for example, the DDC signal levels between a display device and a video source device are compatible, thereby avoiding communication failures or data transmission errors between devices due to level mismatch and optimizing signal transmission quality.

[0063] In order to facilitate a better explanation of this solution in combination with the circuit structure, the circuit example diagram of the complete signal protection path is split apart for explanation in the embodiment of the present application.

[0064] The following combination Figure 5a-5f , which explains the transmission direction of the signal through the HDMI interface protection device.

[0065] As shown in the figure, Figure 5a HDMI1 in the figure indicates the signal receiving port of the HDMI interface protection device. Figure 5e HDMI2 represents the signal output port of the HDMI interface protection device, where the TMDS signal protection path corresponds to the lines of pins 1, 3, 4, 6, 7, 9, 10, and 12 of the port; the DDC signal protection path corresponds to the lines of pins 15 and 16 of the port; and the HPD signal protection path corresponds to the line of pin 19 of the port.

[0066] Specific, combined Figure 5a-5e , an example of the circuit structure for the TMDS signal protection path can be: pins 1, 3, 4, 6, 7, 9, 10, 12 at the signal receiving port are connected to the fuse ( Figure 5a F12-F19), through the first TVS ( Figure 5a After the working circuit protection of TVS10-TVS17) is connected to the first common mode inductor ( Figure 5b The working circuit of CL5-CL8 in the figure is then connected to the retimer chip ( Figure 5c In the embodiment of the present application, the retimer chip U1 may be a retimer chip of the IT66311 model. After the signal is amplified by the retimer chip U1, it is connected from pins 24-16 of the retimer chip U1 to the common mode inductor (RHA2-RHA16 in the figure with even numbers) through the third current limiting resistor (RHA2-RHA16 in the figure with even numbers). Figure 5d CL1-CL4) working circuit, and then through the second TVS ( Figure 5d The working circuit of TVS1-TVS8 in the Figure 5d R3-R10) and the second fuse ( Figure 5d F2-F9), then through TSS ( Figure 5e The working circuits of TSS1-TSS8 in the FPGA are connected to pins 1, 3, 4, 6, 7, 9, 10, and 12 at the signal output port.

[0067] Combine Figure 5a , Figure 5c , Figure 5e , Figure 5f and Figure 5g, the circuit structure of the DDC signal protection path can be: pins 15 and 16 at the signal receiving port are connected to the first fuse ( Figure 5a F20, F21), through the first TVS ( Figure 5a After the working circuit of TVS19, TVS20), through the first current limiting resistor ( Figure 5f RHA48 and RHA51) are connected to the first MOS tube ( Figure 5f Q3, Q4) working circuit, and then connected to the re-timer chip U1 ( Figure 5c After the signal is amplified by the retimer chip U1, it is then connected to the second MOS tube (34,35) that provides the level conversion function via the pins 30,29 of the retimer chip U1. Figure 5g Q5, Q6), then through TVS ( Figure 5g The working circuit of D2, D3) is connected to the second current limiting resistor ( Figure 5g RH25 and RHA27) and the second fuse ( Figure 5g F10, F11), then through TSS ( Figure 5e The working circuit of TSS9, TSS10) is connected to pins 15, 16 at the signal output port.

[0068] Combine Figure 5a , Figure 5c and Figure 5e , the circuit structure of the HPD signal protection path can be: Pin 19 at the signal receiving port is connected to the first fuse ( Figure 5a F22) connects to the first TVS ( Figure 5a The working circuit of TVS18) is then connected to the first current limiting resistor ( Figure 5c RHA17 in the ) is connected to the retimer chip U1 ( Figure 5c After the signal is amplified by the retimer chip, it is connected to the TVS through pin 12 of the retimer chip U1 ( Figure 5c D1 in the working circuit, and then through the second current limiting resistor ( Figure 5c RHA20 in) and the second fuse ( Figure 5c F1 in ), and TSS( Figure 5e The working circuit of TSS11 in Figure 5e The signal is shown as output port at pin 19.

[0069] The HDMI interface protection device provided in the embodiment of the present application is equipped with two-stage protection devices to provide surge protection, and is combined with a retimer chip to enhance the signal, thereby improving the surge resistance of the interface while ensuring signal quality.

[0070] In some embodiments, the HDMI interface protection device further includes a power protection path. Furthermore, the circuit board also integrates a circuit of the power protection path, and the power protection path is used to provide surge protection for the power supply signal.

[0071] Please combine Figure 6 As shown in the figure, the power protection path 14 in the device includes a receiving end power path 141 and an output end power path 142. The signal receiving port 11 is connected to the internal power supply 143 through the receiving end power path, and the internal power supply is connected to the signal output port through the output end power path. The internal power supply 143 can power the retimer chip 133.

[0072] This solution can provide surge protection for the power signal transmission line with at least two levels of protection devices. If a surge voltage occurs in the external power supply connected to the HDMI interface, the power protection path can quickly respond and suppress these surge voltages to protect the internal circuits from damage. For example, it ensures the normal power supply of the retimer chip and improves the device's surge resistance.

[0073] In an embodiment of the present application, the above-mentioned receiving-end power supply path includes the working circuit of the third fuse, the working circuit of the third transient suppression diode, the working circuit of the first magnetic bead, and the working circuit of the diode; the above-mentioned output-end power supply path includes the working circuit of the fourth fuse, the working circuit of the fifth transient suppression diode, the working circuit of the second magnetic bead, and the working circuit of the fourth transient suppression diode.

[0074] For details, please combine Figure 7 , Figure 7 The third fuse in the diagram represents the operating circuit of the third fuse, the third TVS represents the operating circuit of the third transient suppression diode, the first ferrite bead represents the operating circuit of the first ferrite bead, the diode represents the operating circuit of the diode, the fourth TVS represents the operating circuit of the fourth transient suppression diode, the second ferrite bead represents the operating circuit of the second ferrite bead, the fifth TVS represents the operating circuit of the fifth transient suppression diode, and the fourth fuse represents the operating circuit of the fourth fuse. Figure 7The power supply signal enters the signal receiving port at one end of the device and is transmitted to the internal power supply via the receiving power path. In the receiving power path, the third fuse provides overcurrent protection, the third TVS is a high-power TVS that meets the requirements of high-power surge protection, the first ferrite bead filters out high-frequency interference from the power supply, and the diode provides protection against voltage backflow, reducing interference voltage. The internal power supply is used to power internal circuits, such as the retimer chip, and is then connected to the signal output port at the other end of the device via the output power path, forming a complete power supply signal transmission line. In the output power path, the fourth TVS acts as a protective device to suppress static electricity, EFT, and surge voltage. The second ferrite bead filters out high-frequency interference from the power supply, the fifth TVS is also a high-power TVS that meets the requirements of high-power surge protection, and the fourth fuse provides overcurrent protection. Based on this, this solution implements multiple protection circuits for the power supply signal by setting up working circuits for multiple protective devices such as fuses, ferrite beads, and transient suppression diodes in the receiving power path and the output power path. This can effectively resist various forms of power supply interference and surge impacts, ensuring the stability and safety of the power supply signal.

[0075] For details, please combine Figure 5a , Figure 5e , Figure 8a and Figure 8b In the figure, 5V5_HDMI1 represents the power supply signal received by HDMI1. The circuit structure of the power protection path can be: Figure 5a The pin 18 at the signal receiving port shown is connected to the third fuse ( Figure 8a FHA1) connected to the third TVS ( Figure 8a D5) working circuit, and then through the first magnetic bead ( Figure 8a LHA8) and diode ( Figure 8a The working circuit of ED1) is an internal power supply (such as Figure 8a +5VS / +5VS_HDMI) power supply, internal power supply (such as Figure 8b +5VS) through the fourth TVS ( Figure 8b The working circuit of TVS9) is connected to the second magnetic bead ( Figure 8b LHA7), then through the fifth TVS ( Figure 8b After the working circuit of D4) in the middle, the fourth fuse ( Figure 8b FHA2) connected to Figure 5e In order to distinguish the pin 18 of the signal output port from the power supply signal 5VS_HDMI1 of the signal receiving port, the power supply signal provided by the pin 18 of the signal output port is recorded as 5VS_HDMI2.

[0076] The HDMI interface protection device provided in the embodiment of the present application sets a two-level protection path to provide surge protection for the power supply signal and improve the surge resistance of the power supply signal transmission line.

[0077] Please combine Figure 9 In some embodiments, a bypass circuit 134 is further provided between the receiving-end protection path 131 and the output-end protection path 132. The bypass circuit can provide a transmission path for the signal to be transmitted from the signal receiving port directly to the signal output port, thereby preventing the transmission path of the signal to be transmitted from passing through the retimer chip.

[0078] For details, please combine Figure 10a-Figure 10c . Figure 10a This is an example circuit diagram of a bypass circuit corresponding to a TMDS signal provided in an embodiment of the present application. Figure 5a Taking the signal HDMI1_TXP2 corresponding to pin 1 of the signal receiving port as an example, it passes through the receiving end protection path corresponding to the TMDS signal to obtain HDMI1_TXP2_L, without passing through the circuit of the Retimer chip part, but directly passes through Figure 10a The corresponding parts of the bypass circuit shown (resistors RHA55 and RHA63) output the signal HDMI1_TXP2_CON_C, which is then transmitted to pin 1 of the signal output port via the output protection path corresponding to the TMDS signal. The bypass circuit allows the TMDS signal transmission line to bypass the retimer chip.

[0079] Figure 10b This is an example circuit diagram of a bypass circuit corresponding to a DDC signal provided in an embodiment of the present application. Figure 5a Taking the signal HDMI1_SCLC_PCH_R corresponding to pin 15 of the signal receiving port as an example, after the protection of the receiving end protection path corresponding to the DDC signal, it does not pass through the circuit of the Retimer chip part, but directly passes through Figure 10b The corresponding part of the bypass circuit (resistor RHA36, switch tube Q1 and resistor RHA22) outputs the signal TXSCL_R, which then passes through the output protection path corresponding to the DDC signal (which is in Figure 5g The signal TXSCL is obtained from HDMI1_SCLB_PCH and transmitted to pin 15 at the signal output port, thereby allowing the transmission line of the DDC signal to bypass the Retimer chip through the bypass circuit.

[0080] Figure 10c This is an example circuit diagram of a bypass circuit corresponding to an HPD signal provided in an embodiment of the present application. Figure 5aTaking the signal HDMI1_HPDC_PCH corresponding to pin 19 of the signal receiving port as an example, after the protection of the receiving end protection path corresponding to the HPD signal, it does not pass through the circuit of the Retimer chip part, but directly passes through Figure 10c The corresponding part of the bypass circuit (resistor RHA52, resistor RHA53 and resistor RHA54) outputs the signal HDMI_HPD_C, which then passes through the output protection path corresponding to the HPD signal (which is in Figure 5g The signal TXSCL is obtained from HDMI1_HPD_CON and transmitted to pin 19 at the signal output port, thereby allowing the transmission line of the HPD signal to bypass the Retimer chip through the bypass circuit.

[0081] By setting up a bypass circuit, this solution can provide a signal transmission path that does not pass through the retimer chip when the retimer chip is overloaded, fails, or needs to reduce delay, thereby improving the fault tolerance of the device. It can be understood that Figure 10a-Figure 10c The circuit structure shown is only an optional structure in the embodiment of the present application and is not a limitation of its circuit structure. In the embodiment of the present application, a suitable bypass circuit structure can be set according to the usage environment.

[0082] Another embodiment of the present application provides an HDMI interface protection device, comprising a housing and the aforementioned HDMI interface protection device. The housing is made of a conductive material, optionally a metallic conductive material. A signal receiving port is provided at one end of the housing, a signal output port is provided at the other end, and a circuit board is provided within the housing. An isolation capacitor circuit is provided between the housing ground and the internal ground of the circuit board.

[0083] Please combine Figure 11 The working circuit of the isolation capacitor between the chassis ground and the internal ground can be as follows Figure 11 The circuit structure shown. Taking the first circuit structure in the figure as an example, the ground terminal on the left side of the isolation capacitor EC1 and the ground terminal on its right side represent the chassis ground and the internal ground respectively, and the same applies to the other three circuit structures. In the embodiment of the present application, E_GND1 and E_GND2 represent the internal ground corresponding to the signal receiving port (corresponding to Figure 5a G1 and G2 in the figure); E_GND3 and E_GND4 represent the internal grounds corresponding to the signal output ports (corresponding to Figure 5e Based on this, the internal grounds of different circuit parts can be isolated from the chassis ground by high-voltage capacitors through a circuit structure of isolation capacitors in parallel with resistors, thereby protecting the internal circuits.

[0084] For example, when high-frequency noise occurs, it is directly connected to the ground through an isolation capacitor, preventing the noise from propagating through the internal circuit and suppressing the interference of high-frequency noise on the internal circuit. For another example, when electrostatic interference occurs, the size of the electrostatic current is limited by a resistor, reducing the risk of damage to the internal circuit by electrostatic interference. For another example, when encountering a voltage surge (such as lightning induction, power grid fluctuations, etc.), the isolation capacitor first absorbs the surge energy and slowly releases it to the ground through a resistor, thereby preventing the surge voltage from directly impacting the internal circuit.

[0085] This solution configures the protective device to be in a box shape, such as a rectangular box shape, and provides HDMI interfaces at opposite ends of the box as a signal receiving port and a signal output port, respectively. The HDMI interfaces can be directly connected to the box through cables, making it plug-and-play and quick for users. The box also forms an electromagnetic shielding layer to reduce the impact of external electromagnetic interference on the internal circuit. At the same time, an isolation capacitor is provided to electrically isolate the chassis ground from the internal ground, thereby reducing the impact of static electricity on the internal circuit and improving the safety of the device. Combined with the design of the retimer chip, the surge resistance of the line is greatly improved without affecting the signal transmission performance.

[0086] In some embodiments, the exterior of the box is further provided with a grounding screw, which provides a grounding circuit for the box. Electrostatic interference is a common problem in electronic devices. Static electricity can be generated by a variety of factors, such as friction and electromagnetic induction. When static electricity accumulates to a certain level, it can trigger a discharge phenomenon, damaging electronic components and even causing equipment failure. To address this issue, this solution provides a direct grounding path for static electricity on the box by providing a grounding screw. This allows static electricity on the box to be safely conducted to the earth through the grounding circuit, further improving the reliability and stability of the device. Furthermore, its installation and maintenance are relatively simple, making it convenient for users to use.

[0087] It should be noted that the preferred embodiments of the present application are given in the specification and drawings of this application. However, the present application can be implemented in many different forms and is not limited to the embodiments described in this specification. These embodiments are not intended to be additional limitations on the content of this application. The purpose of providing these embodiments is to make the understanding of the disclosure of this application more thorough and comprehensive. In addition, the above-mentioned technical features can be combined with each other to form various embodiments not listed above, which are all considered to be within the scope of the description of this application; further, it is obvious to those skilled in the art that improvements or changes can be made based on the above description, and all such improvements and changes should fall within the scope of protection of the claims attached to this application.

Claims

1. An HDMI interface protection device, characterized in that: It includes a signal receiving port and a signal output port, at least one type of signal protection path is provided between the signal receiving port and the signal output port, the signal protection path is integrated into the circuit board in the form of a circuit, and the signal protection path includes a receiving end protection path, a retimer chip and an output end protection path; The signal receiving port is used to receive a signal to be transmitted, and transmit the signal to be transmitted to the retimer chip through the receiving end protection path; The receiving end protection path is used to provide surge protection for the signal to be transmitted; The retimer chip is used to enhance the signal to be transmitted, and transmit the enhanced signal to be transmitted to the signal output port through the output end protection path, so that the signal output port outputs the enhanced signal to be transmitted; The output end protection path is used to provide surge protection for the enhanced signal to be transmitted.

2. The HDMI interface protection device according to claim 1, wherein: The at least one type of signal protection path includes a hot plug HPD signal protection path, wherein: The receiving end protection device in the receiving end protection path of the HPD signal protection path includes a first fuse, a first transient suppression diode, and a first current-limiting resistor, wherein the working circuit of the first fuse, the working circuit of the first transient suppression diode, and the working circuit of the first current-limiting resistor are connected in series in sequence to provide a transmission path for the HPD signal; The output end protection device in the output end protection path of the HPD signal protection path includes a surge suppression thyristor, a second fuse, a second current limiting resistor, a second transient suppression diode and a third current limiting resistor. The working circuit of the surge suppression thyristor, the working circuit of the second fuse, the working circuit of the second current limiting resistor, the working circuit of the second transient suppression diode and the working circuit of the third current limiting resistor are connected in series in sequence to provide an enhanced transmission line for the HPD signal.

3. The HDMI interface protection device according to claim 1 or 2, characterized in that: The at least one type of signal protection path includes a transition minimized differential signal (TMDS) signal protection path, wherein: The receiving end protection device in the receiving end protection path of the TMDS signal protection path includes a first fuse, a first transient suppression diode, a first current limiting resistor, and a first common-mode inductor. The working circuit of the first fuse, the working circuit of the first transient suppression diode, the working circuit of the first current limiting resistor, and the working circuit of the first common-mode inductor are connected in series in sequence to provide a transmission line for the TMDS signal. The output protection path devices in the output protection path of the TMDS signal protection path include a surge suppression thyristor, a second fuse, a second current limiting resistor, a second transient suppression diode, a second common-mode inductor and a third current limiting resistor. The working circuit of the surge suppression thyristor, the working circuit of the second fuse, the working circuit of the second current limiting resistor, the working circuit of the second transient suppression diode, the working circuit of the second common-mode inductor and the working circuit of the third current limiting resistor are connected in series in sequence to provide an enhanced transmission line for the TMDS signal.

4. The HDMI interface protection device according to claim 1 or 2, characterized in that: The at least one type of signal protection path includes a display data channel (DDC) signal protection path, wherein: The receiving-end protection device in the receiving-end protection path of the DDC signal protection path includes a first fuse, a first transient suppression diode, a first current-limiting resistor, and a first MOS transistor. The working circuit of the first fuse, the working circuit of the first transient suppression diode, the working circuit of the first current-limiting resistor, and the working circuit of the first MOS transistor are connected in series in sequence to provide a transmission path for the DDC signal. The output end protection device in the output end protection path of the DDC signal protection path includes a surge suppression thyristor, a second fuse, a second current limiting resistor, a second transient suppression diode, and a second MOS transistor. The working circuit of the surge suppression thyristor, the working circuit of the second fuse, the working circuit of the second current limiting resistor, the working circuit of the second transient suppression diode, and the working circuit of the second MOS transistor are connected in series in sequence to provide an enhanced transmission line for the DDC signal.

5. The HDMI interface protection device according to claim 1, wherein: The circuit board also integrates a circuit for a power protection path, which is used to provide surge protection for the power supply signal; wherein, the power protection path includes a receiving end power path and an output end power path, the signal receiving port is connected to an internal power supply through the receiving end power path, the internal power supply is connected to the signal output port through the output end power path, and the internal power supply is used to power the retimer chip.

6. The HDMI interface protection device according to claim 5, wherein: The receiving-end power supply path includes a working circuit of a third fuse, a working circuit of a third transient suppression diode, a working circuit of a first magnetic bead, and a working circuit of a diode, wherein the working circuit of the third fuse, the working circuit of the third transient suppression diode, the working circuit of the first magnetic bead, and the working circuit of the diode are sequentially connected in series to provide a transmission line for the power supply signal; The output power path includes a working circuit of a fourth fuse, a working circuit of a fifth transient suppression diode, a working circuit of a second ferrite bead, and a working circuit of a fourth transient suppression diode. The working circuit of the fourth fuse, the working circuit of the fifth transient suppression diode, the working circuit of the second ferrite bead, and the working circuit of the fourth transient suppression diode are connected in series in sequence to provide a transmission line for a power supply signal of an internal power supply.

7. The HDMI interface protection device according to any one of claims 1, 2, 5, and 6, wherein: The receiving end protection path includes working circuits of at least two receiving end protection devices, and the working circuits of at least two receiving end protection devices are connected in series to provide a transmission line for the signal to be transmitted; The output end protection path includes working circuits of at least two output end protection devices, and the working circuits of the at least two output end protection devices are connected in series to provide an enhanced transmission line for the signal to be transmitted.

8. The HDMI interface protection device according to claim 7, wherein: A bypass circuit is also provided between the receiving end protection path and the output end protection path. The bypass circuit is used to provide a transmission line for the signal to be transmitted from the signal receiving port to the signal output port, so that the transmission of the signal to be transmitted does not pass through the retimer chip.

9. An HDMI interface protection device, characterized in that: The device includes an HDMI interface protection device as described in any one of claims 1 to 8 above, and a box body, wherein the box body is made of conductive material, the signal receiving port of the HDMI interface protection device is arranged at one end of the box body, the signal output port of the HDMI interface protection device is arranged at the other end of the box body, and the circuit board of the HDMI interface protection device is arranged inside the box body; an isolation capacitor is arranged between the chassis ground of the box body and the internal ground of the circuit board.

10. The HDMI interface protection device according to claim 9, characterized in that: A grounding screw is provided on the outside of the box body, and the grounding screw is used to provide a grounding circuit for the box body.

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