HDMI interface protection module

Abstract

The HDMI interface protection module comprises a power supply circuit, an HDMI circuit, an ESD electrostatic protection circuit and a current limiting circuit, the power supply circuit, the HDMI circuit and the ESD electrostatic protection circuit are sequentially in communication connection, the current limiting circuit is simultaneously connected with the output end of the HDMI circuit and the output end of the ESD electrostatic protection circuit, the input end of the HDMI circuit is connected with the power supply circuit, and the output end of the HDMI circuit is connected with the power supply circuit. And the output end is connected with the ESD electrostatic protection circuit and the current limiting circuit. According to the utility model, the scheme of combining the electrostatic protection chip and the resistor is adopted, and the hardware scheme is simple and high in efficiency. In the prior art, only a protection chip is added without a resistor, the phenomenon of electrostatic breakdown easily occurs, the main control chip is damaged, the stability of equipment is greatly influenced, and the maintenance cost is huge, and after the scheme is adopted, the problem of damage to the main control chip does not occur any more, and the defect that the damaged main control chip can only be returned to a factory for maintenance in the prior art is overcome. And manpower and material resources are greatly saved.

Description

TECHNICAL FIELD

[0001] The utility model relates to interface protection technical field, especially interface protection module of HDMI. BACKGROUND

[0002] HDMI interface is an external port that is vulnerable to instantaneous damage, so the design of interface electrostatic protection is particularly important. Regarding the problem of HDMI interface protection, due to the need to support hot plug and the inevitable appearance of some EMC radiation due to the limitation of its metal shell structure, the interference problem will have a great threat to the performance of the device. At present, the protection scheme widely used for interface protection generally adds an ESD static protection chip at the interface. According to the actual use effect, the protection effect is not significant, and there are still many problems of static breakdown causing device damage. SUMMARY

[0003] The utility model provides a HDMI interface protection module, it is characterized in passing that, including: HDMI circuit, ESD static protection circuit and current -limiting circuit,

[0004] The HDMI circuit and ESD static protection circuit are sequentially electrically connected, and the current-limiting circuit is connected to the output end of the HDMI circuit and the ESD static protection circuit;

[0005] The HDMI circuit output end is connected with ESD static protection circuit and current -limiting circuit.

[0006] Optionally, the HDMI interface protection module is characterized by:

[0007] The ESD static protection circuit is used to prevent static discharge from damaging sensitive electronic elements and to absorb high-voltage pulses generated by transient events in the circuit.

[0008] The current-limiting circuit is used to cooperate with the ESD static protection circuit to divide voltage and slow down ESD energy.

[0009] Optionally, the current-limiting circuit is used to cooperate with the ESD static protection circuit to divide voltage and slow down ESD energy, comprising:

[0010] The current-limiting circuit includes a protection resistor group matched with the number of HDMI circuit output terminals. These resistors are connected to the output end of the ESD static protection circuit, and each HDMI circuit output terminal is connected to a protection resistor.

[0011] Optionally, the ESD static protection circuit is used to prevent static discharge from damaging sensitive electronic elements and to absorb high-voltage pulses generated by transient events in the circuit, comprising:

[0012] The ESD static protection circuit is composed of two ESD static protection chips of TEVA0R4V05D4X, and is connected with the output port of the HDMI respectively.

[0013] Optionally, the HDMI interface protection module has the characteristics that:

[0014] When the electrostatic discharge or transient high voltage is generated by the HDMI circuit and enters the circuit, the ESD static protection chip enters a low resistance state to form a low impedance path, and the high voltage pulse energy is guided to the ground;

[0015] The resistance is connected in series with the output end of the ESD static protection chip, and the resistance consumes part of the energy by heating to limit the output current.

[0016] Optionally, the resistance value of the protection resistance is 3.3 ohms to 10 ohms.

[0017] Optionally, the HDMI interface protection module has the characteristics that:

[0018] The power supply circuit is provided with a voltage stabilizing diode SL34A to perform low forward voltage drop and complete low voltage and large current rectification.

[0019] Optionally, the HDMI interface protection module has the characteristics that:

[0020] The output end in the HDMI circuit which is not connected with the ESD static protection circuit is directly connected with the current limiting circuit to perform current limiting.

[0021] Optionally, the HDMI interface protection module has the characteristics that:

[0022] The ESD static protection circuit and the current limiting circuit as protection circuits are arranged as close to the HDMI interface as possible within the allowable range of conditions.

[0023] Optionally, the HDMI interface protection module has the characteristics that:

[0024] The HDMI interface protection module device is arranged in the shell.

[0025] The beneficial effects of the utility model are that: the scheme of combining the electrostatic protection chip and the resistance is simple and efficient, the previous scheme without resistance only with the protection chip is easy to cause the phenomenon of electrostatic breakdown, damages the main control chip, has great influence on the equipment stability and great maintenance cost, after adopting the scheme, the problem of damaging the main control chip does not appear again, the defect that the main control chip can only be returned to the factory for maintenance is overcome, and the manpower and material resources are greatly saved. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following briefly introduces the drawings needed in the embodiment or prior art description. Obviously, the drawings in the following description only represent the embodiments of the present application, and for those skilled in the field, other drawings can be obtained without creative labor on the basis of the provided drawings.

[0027] Figure 1 The principle block diagram of the HDMI interface protection module disclosed by the present application is shown;

[0028] Figure 2 The circuit diagram of the HDMI interface protection module disclosed by the present application is shown;

[0029] Figure 3 The structural diagram of the HDMI interface protection module disclosed by the present application is shown. DETAILED DESCRIPTION

[0030] Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. The same reference signs in the drawings represent functionally identical or similar elements. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

[0031] Among them, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more than two, unless otherwise specifically limited.

[0032] The special word "exemplary" here means "as an example, embodiment or illustrative". Any embodiment described as "exemplary" here is not necessarily interpreted as superior or better than other embodiments.

[0033] In addition, in order to better illustrate the present application, a large number of specific details are given in the specific embodiments below. Those skilled in the art should understand that without certain specific details, the present application can also be implemented. In some examples, methods, means, elements and circuits familiar to those skilled in the art are not described in detail, in order to highlight the main idea of the present application.

[0034] As Figure 1 shown, Figure 1The utility model discloses a kind of HDMI interface protection module's principle diagram, it is characterized in that, HDMI display screen includes power supply circuit, HDMI interface socket includes HDMI circuit, ESD electrostatic protection chip belongs to ESD electrostatic protection circuit, protection resistance belongs to current limiting circuit.

[0035] Specifically, current is inputted into HDMI interface socket from HDMI display screen, and then current is outputted through different pins of HDMI respectively and enters ESD electrostatic protection chip and protection resistance, wherein the current entering ESD electrostatic protection chip needs to be inputted into protection resistance after passing through chip, and finally all currents are inputted into ARM master control chip after passing through protection resistance.

[0036] Among them, ESD (Electro-Static Discharge) electrostatic protection chip is in high resistance state when it is in normal working voltage range, and almost no current is consumed, which has no effect on current. When electrostatic discharge or transient high-voltage pulse enters the circuit, the voltage rises rapidly beyond the chip breakdown voltage, in which case the chip will immediately become low resistance state to form a low impedance path, and the high-voltage pulse energy will be quickly directed to the ground to avoid entering the main control circuit to be protected. When ESD (i.e. electrostatic discharge) ends, the chip returns to high resistance state.

[0037] In addition, protection resistance has negligible effect on signal transmission or power supply when the circuit is working normally due to its small resistance value, limits transient current in ESD event, reduces the current pressure borne by ESD electrostatic protection chip and subsequent circuit, and cooperates with ESD electrostatic protection chip to further reduce the voltage across the elements of the main control circuit. Protection resistance also consumes part of the energy through heat to reduce the energy transmitted to the subsequent circuit.

[0038] The utility model is applied to HDMI video transmission, and is an HDMI interface protection module, which has power supply circuit, HDMI circuit, ESD electrostatic protection circuit and current limiting circuit inside, is suitable for 4K and 2K video transmission scene, protects the circuit under normal image effect, and transmits image information to the main control circuit through the module.

[0039] Specifically, the power supply circuit, HDMI circuit and ESD electrostatic protection circuit are sequentially connected in communication, and the current limiting circuit is connected to the output end of HDMI circuit and ESD electrostatic protection circuit simultaneously; the input end of HDMI circuit is connected to power supply circuit, and the output end is connected to ESD electrostatic protection circuit and current limiting circuit.

[0040] For example, Figure 2As shown, the power supply circuit includes voltage stabilizing diode D9 and capacitor C105, the HDMI circuit includes HDMI socket J1, the ESD static protection circuit includes ESD voltage stabilizing chips U14, U15, and the current limiting circuit includes 3.3-ohm resistors R163 to R170 and 100-ohm resistors R171 to R173.

[0041] Specifically, the input current passes through voltage stabilizing diode D9 and capacitor C105 in sequence, then enters HDMI socket J1, and then is output through different pins. Pin 1, 3, 4, and 6 input ESD voltage stabilizing chip U15, and then are output to resistors R163, R164, R165, and R166 in sequence. Pin 12, 10, 9, and 7 input ESD voltage stabilizing chip U14, and then are output to resistors R167, R168, R169, and R170 in sequence. Pin 15, 16, and 19 input resistors R171, R172, and R173 in sequence, and finally the above resistors R163 to R173 are output to the main control circuit.

[0042] Specifically, the ESD static protection circuit is used to prevent static discharge from damaging sensitive electronic elements and to absorb high-voltage pulses generated by transient events in the circuit. The current limiting circuit is used to cooperate with the ESD static protection circuit to divide voltage and slow down ESD energy.

[0043] The ESD static protection circuit is composed of two TEVA0R4V05D4X ESD static protection chips and is connected to the output port of the HDMI. When static discharge or transient high voltage is generated by the HDMI circuit and enters the circuit, the ESD static protection chip enters a low resistance state to form a low impedance path, guiding the high-voltage pulse energy to the ground. The resistors are connected in series with the output end of the ESD static protection chip, and the resistors consume part of the energy through heat dissipation to limit the output current.

[0044] Specifically, the current limiting circuit is composed of R0402 resistors, which are connected to the output end of the ESD static protection circuit. The resistance value of the R0402 resistor ranges from 3.3 ohms to 10 ohms, because the output is stable and the image effect is normal in this resistance value range. The resistance value of the resistor is 0 ohm to 3.3 ohm, and the protection effect is not significant. The resistance value of the resistor is greater than 10 ohms, and the image appears abnormal.

[0045] Among them, according to the actual test needs, and cooperate with the actual interface transmission rate required, increase the resistance after ESD static protection, the test resistance value is too big to affect the transmission of effective data causes the image effect damage phenomenon, take the 4K and 2K output of HDMI as an example to test, the protection resistance of HDMI output end is externally connected, and the protection effect is very small between 0 and 3.3 ohms or there will be damage problems, 3.3 ohms to 10 ohms this resistance value range has no effect on the effect of the picture, 10 ohm resistance value above the picture starts to appear image fixed screen has vertical stripe phenomenon. The 3.3 ohm resistance tested by a large number of experiments can effectively avoid the surge static threat, and there is no data packet loss phenomenon.

[0046] Specifically, the power supply circuit is provided with a voltage stabilizing diode SL34A to perform low forward voltage drop and complete low voltage and large current rectification.

[0047] Among them, the forward voltage drop (usually 0.2V to 0.4V) of the voltage stabilizing diode SL34A is lower than that of the ordinary diode (0.6V to 0.7V), which is suitable for low voltage application, and the switching speed of the Schottky diode is extremely fast due to the absence of minority carrier storage effect, which is suitable for high frequency circuit.

[0048] As shown in Figure 3 By optimizing the PCB layout, the ESD protection element is as close to the HDMI interface as possible, the propagation path of the ESD energy is shortened, and the ground wire design is optimized to ensure that the ESD energy can be quickly discharged.

[0049] The above has described various embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles, practical applications or improvements to the technology in the market of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. An HDMI interface protection module, characterized in that, The HDMI circuit, the ESD static protection circuit and the current limiting circuit are sequentially connected. The HDMI circuit and the ESD static protection circuit are sequentially connected, and the current limiting circuit is connected to the output terminals of the HDMI circuit and the ESD static protection circuit. The HDMI circuit is connected to the ESD static protection circuit and the current limiting circuit.

2. The HDMI interface protection module of claim 1, wherein: The ESD static protection circuit is used to prevent electrostatic discharge from damaging sensitive electronic components and to absorb high-voltage pulses generated by transient events in the circuit. The current limiting circuit is used to cooperate with the ESD static protection circuit to divide voltage and slow down ESD energy. The current limiting circuit is used to cooperate with the ESD static protection circuit to divide voltage and slow down ESD energy, comprising:

3. The HDMI interface protection module of claim 2, wherein, The current limiting circuit includes a set of protection resistors that match the number of output terminals of the HDMI circuit, and each protection resistor is connected to an output terminal of the ESD static protection circuit. The ESD static protection circuit is used to prevent electrostatic discharge from damaging sensitive electronic components and to absorb high-voltage pulses generated by transient events in the circuit, comprising:

4. The HDMI interface protection module of claim 2, wherein, The ESD static protection circuit is composed of two TEVA0R4V05D4X ESD static protection chips, which are connected to the output ports of the HDMI.

5. The HDMI interface protection module of claim 2, wherein: When electrostatic discharge or transient high voltage is generated by the HDMI circuit and enters the circuit, the ESD static protection chip enters a low resistance state to form a low impedance path and direct the high-voltage pulse energy to the ground. The resistor is connected in series with the output terminal of the ESD static protection chip, and the resistor consumes part of the energy through heat dissipation to limit the output current. The resistance value of the protection resistor ranges from 3.3 ohms to 10 ohms.

6. The HDMI interface protection module of claim 3, wherein, 7. The HDMI interface protection module of claim 1, wherein: The power supply circuit is equipped with a voltage stabilizing diode SL34A to perform low forward voltage drop and complete low-voltage and high-current rectification.

8. The HDMI interface protection module of claim 1, wherein: The output terminals of the HDMI circuit that are not connected to the ESD static protection circuit are directly connected to the current limiting circuit for current limiting.

9. The HDMI interface protection module of claim 1, wherein: The ESD static protection circuit and the current limiting circuit, as protection circuits, are arranged as close as possible to the HDMI interface within the allowable range of conditions.

10. An HDMI interface protection module, comprising: The HDMI interface protection module device of any one of claims 1 to 9 is arranged in the housing. ​

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