CN216649235U

CN216649235U - HDMI port protection circuit and HDMI port protection device

Info

Publication number: CN216649235U
Application number: CN202123270801.4U
Authority: CN
Inventors: 韩威巍; 王江; 沈文钊; 冉杰; 张友近; 李友峰; 林松川
Original assignee: Shenzhen Skyworth RGB Electronics Co Ltd
Current assignee: Shenzhen Skyworth RGB Electronics Co Ltd
Priority date: 2021-12-23
Filing date: 2021-12-23
Publication date: 2022-05-31
Anticipated expiration: 2031-12-23

Abstract

The utility model discloses an HDMI port protection circuit and an HDMI port protection device, wherein the HDMI port protection circuit is connected with a mainboard, and comprises: the HDMI transmission module, the HDMI receiving module, the data input protection module and the data input module; the HDMI transmitting module is used for transmitting a data signal and a transmission voltage signal to the HDMI receiving module; the HDMI receiving module is used for transmitting the data signal to the data input module and transmitting the voltage signal to the data input protection module after receiving the data signal and the voltage signal; the data input protection module is used for pulling down the voltage of the data signal when detecting that the voltage signal is greater than a preset threshold value; the data input module is used for transmitting the pulled-down data signal to the mainboard. According to the utility model, when the data input protection module detects that the voltage signal is greater than the preset threshold value, the voltage of the data signal is reduced, so that the problem that the HDMI interface and the signal processing chip are damaged in overvoltage can be effectively solved.

Description

HDMI port protection circuit and HDMI port protection device

Technical Field

The utility model relates to the technical field of electronic circuits, in particular to an HDMI port protection circuit and an HDMI port protection device.

Background

HDMI has gradually become a more general input/output interface for global audio/video devices, and the use of HDMI has tended to be frequent. Meanwhile, 5V and 12V adapters are increasingly used, and the interfaces of the two adapters are the same, so that common users can easily confuse the use of the 5V and 12V adapters.

When a user uses the HDMI signal transmitting device, the 12V power adapter is misused to supply power to the HDMI signal transmitting device, and when the 12V adapter is accessed incorrectly, a 12V power voltage exists on the data output port I2C signal line of the HDMI transmitting device, so that a 12V high voltage is also received at the HDMI signal receiving end of the TV, and the 12V high voltage on the signal line can damage the data input port of the HDMI receiving device, or even damage the corresponding signal processing chip. Since the HDMI signal sink of the TV should normally be a 5V power input.

The existing improvement scheme is as follows: a TVs (Transient Voltage regulator, TVs for short) with a flyback function is added to each pin of the HDMI signal receiving end of the TV, which is associated with a power input, and is different from a general Voltage-stabilizing TVs, for example, when the TVs with the flyback function receives 12V Voltage, the Voltage drop of the TVs can be directly stabilized at 3.3V, and when the TVs receives 5V Voltage, the TVs is high-impedance, and the Voltage drop is maintained at 5V, as shown in RV2J2 and RV1J2 in fig. 1, so that the HDMI signal receiving end of the TV can be clamped at about 5V when receiving 12V power, thereby protecting each pin port of the TV end.

However, this improvement has the following disadvantages: 1. the TVS tube with the back scanning function is higher in price; 2. the suitable selectable models are few, the universality is poor, and the mass production shortage is easy to cause; 3. the TVS works in an abnormal state for a long time and is easy to damage.

Thus, the prior art has yet to be improved and enhanced.

SUMMERY OF THE UTILITY MODEL

The utility model mainly aims to provide an HDMI port protection circuit and an HDMI port protection device, and aims to solve the problems that in the prior art, TVS tubes with a back-scanning function are added to pins associated with power input of an HDMI signal receiving end of a TV, but the TVS tubes with the back-scanning function are high in cost, poor in universality and easy to damage, so that the circuit is high in cost and abnormal easily occurs.

In order to achieve the purpose, the utility model adopts the following technical scheme:

an HDMI port protection circuit connected to a motherboard, the HDMI port protection circuit comprising: the HDMI transmission module, the HDMI receiving module, the data input protection module and the data input module; the HDMI transmitting module is sequentially connected with the HDMI receiving module, the data input protection module, the data input module and the mainboard; the HDMI transmitting module is used for transmitting a data signal and a transmission voltage signal to the HDMI receiving module; the HDMI receiving module is used for transmitting the data signal to the data input module and transmitting the voltage signal to the data input protection module after receiving the data signal and the voltage signal; the data input protection module is used for pulling the voltage of the low data signal when the voltage signal is detected to be larger than a preset threshold value; the data input module is used for transmitting the pulled-down data signal to the mainboard.

In the HDMI port protection circuit, the data input protection module includes: a control unit and a switch unit; the control unit and the switch unit are both connected with the HDMI receiving module, and the switch unit is also respectively connected with the data input module and the control unit; the control unit is used for generating a control voltage to the switch unit when detecting that the voltage signal is greater than the preset threshold value; the switch unit is used for normally working according to the control voltage.

In the HDMI port protection circuit, the HDMI transmitting module includes: a first interface; the 2 nd pin, the 5 th pin, the 8 th pin, the 11 th pin, the 17 th pin, the 20 th pin, the 21 st pin, the 22 nd pin and the 23 rd pin of the first interface are all grounded, and the 1 st pin, the 3 rd pin, the 4 th pin, the 6 th pin, the 7 th pin, the 9 th pin, the 10 th pin, the 12 th pin, the 13 th pin, the 14 th pin, the 15 th pin, the 16 th pin, the 18 th pin and the 19 th pin of the first interface are all connected with the HDMI receiving device.

In the HDMI port protection circuit, the HDMI receiving module includes: a second interface; the 2 nd pin, the 5 th pin, the 8 th pin, the 11 th pin, the 17 th pin, the 20 th pin, the 21 st pin, the 22 nd pin and the 23 rd pin of the second interface are all grounded, and the 1 st pin, the 3 rd pin, the 4 th pin, the 6 th pin, the 7 th pin, the 9 th pin, the 10 th pin, the 12 th pin, the 13 th pin, the 14 th pin, the 15 th pin, the 16 th pin, the 18 th pin and the 19 th pin of the second interface are correspondingly connected with the 1 st pin, the 3 rd pin, the 4 th pin, the 6 th pin, the 7 th pin, the 9 th pin, the 10 th pin, the 12 th pin, the 13 th pin, the 14 th pin, the 15 th pin, the 16 th pin, the 18 th pin and the 19 th pin of the first interface one to one; and the 18 th pin of the second interface is also connected with the data input protection module.

In the HDMI port protection circuit, the control unit comprises a first resistor, a second resistor, a diode and a triode; a collector of the triode is connected with the pin 18 of the second interface, a base of the triode is connected with a cathode of the diode, an anode of the diode is connected with one end of the first resistor, and the other end of the first resistor is grounded; and the emitting electrode of the triode is respectively connected with one end of the second resistor and the switch unit, and the other end of the second resistor is grounded.

In the HDMI port protection circuit, the switch unit includes: the first switch tube and the second switch tube; the first end of the first switch tube and the first end of the second switch tube are both connected with one end of the second resistor and the emitter of the triode; the second end of the first switch tube is respectively connected with the 15 th pin of the second interface and the data input module, and the third end of the first switch tube is grounded; the second end of the second switch tube is connected with the 16 th pin of the second interface and the data input module, and the third end of the second switch tube is grounded.

In the HDMI port protection circuit, the data input module includes: a third resistor, a fourth resistor, a fifth resistor and a sixth resistor; one end of the third resistor and one end of the fourth resistor are connected with the 18 th pin of the second interface, the other end of the third resistor is connected with the 15 th pin of the second interface, the second end of the first switch tube and one end of the fifth resistor, the other end of the fifth resistor is connected with the main board, the other end of the fourth resistor is connected with the 16 th pin of the second interface, the second end of the second switch tube and one end of the sixth resistor, and the other end of the sixth resistor is connected with the main board.

In the HDMI port protection circuit, the first switch tube is a first MOS tube, the first end of the first switch tube is the source electrode of the first MOS tube, the second end of the first switch tube is the drain electrode of the first MOS tube, and the third end of the first switch tube is the gate electrode of the first MOS tube.

In the HDMI port protection circuit, the second switching tube is a second MOS tube, a first end of the second switching tube is a source electrode of the second MOS tube, a second end of the second switching tube is a drain electrode of the second MOS tube, and a third end of the second switching tube is a gate electrode of the second MOS tube.

The HDMI port protection device comprises a PCB, wherein the PCB is provided with the HDMI port protection circuit.

Compared with the prior art, the HDMI port protection circuit and the HDMI port protection device provided by the utility model have the advantages that the HDMI port protection circuit is connected with the mainboard, and the HDMI port protection circuit comprises: the HDMI transmission module, the HDMI receiving module, the data input protection module and the data input module; the HDMI transmitting module is sequentially connected with the HDMI receiving module, the data input protection module, the data input module and the mainboard; the HDMI transmitting module is used for transmitting a data signal and a transmission voltage signal to the HDMI receiving module; the HDMI receiving module is used for transmitting the data signal to the data input module and transmitting the voltage signal to the data input protection module after receiving the data signal and the voltage signal; the data input protection module is used for pulling the voltage of the low data signal when detecting that the voltage signal is greater than a preset threshold value; the data input module is used for transmitting the pulled-down data signal to the mainboard. When the data input protection module detects that the voltage signal is greater than the preset threshold value, the voltage of the low data signal is pulled, and the problem that the HDMI interface and the signal processing chip are damaged in overvoltage can be effectively solved.

Drawings

FIG. 1 is a schematic diagram of an HDMI port protection circuit according to the prior art;

fig. 2 is a block diagram of an HDMI port protection circuit according to the present invention;

fig. 3 is a circuit diagram of an HDMI transmitting module in the HDMI port protection circuit according to the present invention;

fig. 4 is a circuit diagram of an HDMI receiving module in the HDMI port protection circuit according to the present invention;

fig. 5 is a circuit diagram of a data input protection module in the HDMI port protection circuit according to the present invention;

fig. 6 is a circuit diagram of a data input module in the HDMI port protection circuit according to the present invention.

Reference numerals: 10: an HDMI port protection circuit; 20: a main board; 100: an HDMI transmission module; 200: an HDMI receiving module; 300: a data input protection module; 310: a control unit; 320: a switch unit; 400: a data input module; r1: a first resistor; r2: a second resistor; r3: a third resistor; r4: a fourth resistor; r5: a fifth resistor; r6: a sixth resistor; q1: a triode; q2: a first switch tube; q3: a second switching tube; j1: a first interface; j2: a second interface; d1: and a diode.

Detailed Description

In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or wirelessly coupled. As used herein, the term "and/or" includes all or any element and all combinations of one or more of the associated listed items.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

According to the HDMI port protection circuit and the HDMI port protection device, when the data input protection module detects that the voltage signal is greater than the preset threshold value, the voltage of the data signal is reduced, and therefore the problem that an HDMI interface and a signal processing chip are damaged in overvoltage can be effectively solved.

The following describes a design scheme of an HDMI port protection circuit by using specific exemplary embodiments, and it should be noted that the following embodiments are only used to explain technical solutions of the present invention, and are not specifically limited:

referring to fig. 2, the HDMI port protection circuit 10 provided by the present invention is connected to a main board 20, and the HDMI port protection circuit 10 includes: the HDMI transmitter module 100, the HDMI receiver module 200, the data input protection module 300, and the data input module 400; the HDMI transmitting module 100 is sequentially connected to the HDMI receiving module 200, the data input protection module 300, the data input module 400, and the main board 20; the HDMI transmitting module 100 is configured to transmit a data signal and a transmission voltage signal to the HDMI receiving module 200; the HDMI receiving module 200 is configured to transmit the data signal to the data input module 400 and transmit the voltage signal to the data input protection module 300 after receiving the data signal and the voltage signal; the data input protection module 300 is configured to pull down the voltage of the data signal when detecting that the voltage signal is greater than a preset threshold (for example, the preset threshold is 5.6V in this embodiment); the data input module 400 is configured to transmit the data signal to the motherboard 20.

Specifically, firstly, the HDMI sending module 100 is connected to the HDMI receiving module 200 through an HDMI connection line, and at this time, the HDMI sending module 100 sends the data signal and the voltage signal to the HDMI receiving module 200; secondly, after the receiving module receives the voltage signal, the receiving module transmits the voltage signal to the data input protection module 300 and transmits the data signal to the data input module 400; then, the data input protection module 300 detects whether the voltage signal is greater than a preset threshold: when detecting that the voltage signal is greater than the preset threshold, performing overvoltage protection, that is, pulling down the voltage of the data signal, and then transmitting the data signal with the voltage pulled down to a corresponding processing chip on the motherboard 20 by the data input module 400, and finally, performing normal data processing operation by the motherboard 20; when detecting that the voltage signal is not greater than the preset threshold, the data input protection module 300 does not pull down the voltage of the data signal, the data input module 400 directly transmits the data signal to a corresponding processing chip on the motherboard 20, and finally, the motherboard 20 performs normal data processing operation. According to the data input module 400, when the voltage signal is detected to be greater than the preset threshold value, the voltage of the data signal is reduced, so that the HDMI port and the corresponding signal processing chip are effectively protected, and the HDMI port and the corresponding signal processing chip are prevented from being damaged.

Further, referring to fig. 3, the HDMI transmitting module 100 includes: a first interface J1; the 2 nd pin, the 5 th pin, the 8 th pin, the 11 th pin, the 17 th pin, the 20 th pin, the 21 st pin, the 22 nd pin and the 23 rd pin of the first interface J1 are all grounded, and the 1 st pin, the 3 rd pin, the 4 th pin, the 6 th pin, the 7 th pin, the 9 th pin, the 10 th pin, the 12 th pin, the 13 th pin, the 14 th pin, the 15 th pin, the 16 th pin, the 18 th pin and the 19 th pin of the first interface J1 are all connected with the HDMI receiving device.

Specifically, after the first interface J1 on the HDMI transmitting device is connected to the HDMI receiving device through the HDMI connecting line, the HDMI transmitting device transmits the data signal and the voltage signal to the HDMI receiving device for the next operation. In the utility model, the first interface J1 on the HDMI transmitting device is connected with the HDMI receiving device through the HDMI connecting line, so that data transmission is effectively and stably performed.

Further, referring to fig. 4, the HDMI receiving module 200 includes: a second interface J2; the 2 nd pin, the 5 th pin, the 8 th pin, the 11 th pin, the 17 th pin, the 20 th pin, the 21 st pin, the 22 nd pin and the 23 rd pin of the second interface J2 are all grounded, and the 1 st pin, the 3 rd pin, the 4 th pin, the 6 th pin, the 7 th pin, the 9 th pin, the 10 th pin, the 12 th pin, the 13 th pin, the 14 th pin, the 15 th pin, the 16 th pin, the 18 th pin and the 19 th pin of the second interface J2 are connected with the 1 st pin, the 3 rd pin, the 4 th pin, the 6 th pin, the 7 th pin, the 9 th pin, the 10 th pin, the 12 th pin, the 13 th pin, the 14 th pin, the 15 th pin, the 16 th pin, the 18 th pin and the 19 th pin of the first interface J1 in a one-to-one correspondence manner; the 18 th pin (HDMI _5V port in the present embodiment) of the second interface J2 is further connected to the data input protection module 300.

Specifically, after the first interface J1 on the HDMI transmitting device is connected to the second interface J2 on the HDMI receiving device through the HDMI connecting line, the HDMI transmitting device transmits the data signal and the voltage signal to the HDMI receiving device for the next operation. In the utility model, the first interface J1 on the HDMI transmitting device is connected with the second interface J2 on the HDMI receiving device through the HDMI connecting line, so that data transmission is effectively and stably carried out.

Further, referring to fig. 5, the data input protection module 300 includes: a control unit 310 and a switching unit 320; the control unit 310 and the switch unit 320 are both connected to the HDMI receiving module 200, and the switch unit 320 is also connected to the data input module 400 and the control unit 310, respectively; the control unit 310 is configured to generate a control voltage to the switch unit 320 when detecting that the voltage signal is greater than a preset threshold; the switch unit 320 is used for normal operation according to the control voltage.

Specifically, when the HDMI receiving module 200 receives the data signal and the voltage signal, transmits the data signal to the data input module 400, and transmits the voltage signal to the data input protection module 300, the control unit 310 detects whether the voltage signal is greater than the preset threshold: if the voltage is larger than the predetermined value, a control signal is generated to the switch unit 320, and the switch unit 320 performs normal operation according to the control signal, so as to pull down the voltage of the data signal, thereby effectively protecting the HDMI port and the corresponding signal processing chip. The control unit 310 generates the control signal according to the magnitude of the voltage signal, and then the switch unit 320 is turned on according to the control signal, so that accurate ground voltage detection and switch control are formed, and the HDMI port and the corresponding signal processing chip are effectively protected.

Further, the control unit 310 includes: the circuit comprises a first resistor R1, a second resistor R2, a diode D1 and a triode Q1; a collector of the triode Q1 is connected to the pin 18 of the second interface J2, a base of the triode Q1 is connected to a cathode of the diode D1, an anode of the diode D1 is connected to one end of the first resistor R1, and the other end of the first resistor R1 is grounded; the emitter of the transistor Q1 is connected to one end of the second resistor R2 and the switch unit 320, respectively, and the other end of the second resistor R2 is grounded. Wherein the diode D1 is a zener diode.

Specifically, when the pin 18 of the second interface J2 transmits the voltage signal to the collector of the transistor Q1, the transistor Q1 first detects whether the voltage value is greater than the preset threshold, and if the transistor Q1 detects that the voltage signal is greater than the preset threshold, an overvoltage occurs, the diode D1 is turned on, and at this time, the base and the collector of the transistor Q1 are forward biased to be turned on, so that the collector and the emitter of the transistor Q1 are also turned on, that is, the transistor Q1 is turned on, and at this time, the transistor Q1 generates a control signal to the switching unit 320, so that the switching unit 320 further operates. Whether the voltage signal is greater than the preset threshold value or not is detected through the triode Q1, so that whether the second interface J2 is over-voltage or not is effectively judged, further action is taken in time, and an accurate and rapid voltage detection system is effectively formed.

Further, the switching unit 320 includes: a first switch tube Q2 and a second switch tube Q3; a first end of the first switch tube Q2 and a first end of the second switch tube Q3 are both connected with one end of the second resistor R2 and the emitter of the transistor Q1; the second terminal of the first switch tube Q2 is connected to the 15 th pin (HDMI _ SCL port in this embodiment) of the second interface J2 and the data input module 400, respectively, and the third terminal of the first switch tube Q2 is grounded; the second terminal of the second switch Q3 is connected to the 16 th pin (HDMI _ SDA port in this embodiment) of the second interface J2 and the data input module 400, and the third terminal of the second switch Q3 is grounded.

Specifically, when the first interface J1 detects that the voltage signal is greater than the preset threshold, the diode D1 is turned on, the transistor Q1 is also turned on, the transistor Q1 generates a control signal to the first switch tube Q2, at this time, the control signal is at a high level, so the first switch tube Q2 is turned on according to the control signal at the high level, and then the second switch tube Q3 is also turned on, so that the data signal is turned on to the ground, the voltage of the data signal is pulled down, and the HDMI port and the corresponding signal processing chip are protected; when the first interface J1 detects that the voltage signal is not greater than the preset threshold, the diode D1 is turned off, the transistor Q1 is also turned off, the transistor Q1 cannot generate a control signal to the switch unit 320, at this time, the first switch tube Q2 and the second switch tube Q3 are both turned off, and the data signal is normally transmitted. According to the utility model, the switch unit 320 is arranged to form a path to the ground to pull down the data signal when overvoltage occurs, so that overvoltage is protected rapidly, and an HDMI port and a corresponding signal processing chip are protected well; when the data signal is not over-voltage, the data signal is not processed, so that the normal voltage magnitude of the data signal is not influenced.

Further, referring to fig. 6, the data input module 400 includes: a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6; one end of the third resistor R3 and one end of the fourth resistor R4 are both connected to the 18 th pin of the second interface J2, the other end of the third resistor R3 is connected to the 15 th pin of the second interface J2, the second end of the first switch tube Q2 and one end of the fifth resistor R5, the other end of the fifth resistor R5 is connected to the main board 20 (through the SOC _ SCL port in this embodiment), the other end of the fourth resistor R4 is connected to the 16 th pin of the second interface J2, the second end of the second switch tube Q3 and one end of the sixth resistor R6, and the other end of the sixth resistor R6 is connected to the main board 20 (through the SOC _ SDA port in this embodiment).

Further, the first switch tube Q2 is a first MOS transistor, the first end of the first switch tube Q2 is a source electrode of the first MOS transistor, the second end of the first switch tube Q2 is a drain electrode of the first MOS transistor, and the third end of the first switch tube Q2 is a gate electrode of the first MOS transistor.

Further, the second switch tube Q3 is a second MOS transistor, the first end of the second switch tube Q3 is a source electrode of the second MOS transistor, the second end of the second switch tube Q3 is a drain electrode of the second MOS transistor, and the third end of the second switch tube Q3 is a gate electrode of the second MOS transistor.

For a better understanding of the present invention, the operation of the HDMI port protection circuit 10 of the present invention is described in detail below with reference to fig. 3-6:

when the first interface J1 on the HDMI transmitting device is connected to the second interface J2 on the HDMI receiving device through the HDMI connection line, firstly, the HDMI transmitting device transmits the data signal and the voltage signal to the HDMI receiving device, and then, the voltage signal is transmitted to the transistor Q1 through the 15 pin of the second interface J2, i.e. the HDMI _5V port of the second interface J2 in this embodiment, at this time, the second interface J2 detects whether the voltage value is greater than the preset threshold value; if the voltage signal is greater than the predetermined threshold value (in this embodiment, +5.6V), the diode D1 is turned on, then the transistor Q1 is also turned on, then the emitter terminal of the transistor Q1 is at a high level, that is, the transistor Q1 generates a high-level control signal to the first switching tube Q2 and the second switching tube Q3, since the high-level control signal is greater than the turn-on voltage of the first switching tube Q2 and the second switching tube Q3, both the first switching tube Q2 and the second switching tube Q3 are turned on, and the drains of the first switching tube Q2 and the second switching tube Q3 are grounded, the voltage of the data signal is pulled down, and finally, the pulled-down data signal is transmitted to the corresponding processing chip on the main board 20 through the fifth resistor R5 and the sixth resistor R6.

If the voltage signal is not greater than the preset threshold, the diode D1 is turned off, then the transistor Q1 is also turned off, then the emitting terminal of the transistor Q1 is at a low level, that is, the transistor Q1 generates a low-level control signal to the first switch tube Q2 and the second switch tube Q3, since the high-level control signal is smaller than the on-state voltage of the first switch tube Q2 and the second switch tube Q3, both the first switch tube Q2 and the second switch tube Q3 are turned off, at this time, the voltage of the data signal is maintained at the original level, and a normal data signal is transmitted to the corresponding processing chip on the main board 20 through the fifth resistor R5 and the sixth resistor R6.

According to the utility model, some peripheral circuits are added to the TV complete machine and all the HDMI receiving devices, when a user uses the 12V adapter by mistake, the data transmission between the HDMI sending device and the HDMI receiving device can be automatically closed, so that the HDMI receiving device and the corresponding processing chip are protected; when the 12V adapter is removed, the HDMI receiving device automatically and normally receives the data transmitted by the HDMI transmitting device. Therefore, the damage of the HDMI port and the corresponding signal processing chip can be effectively prevented, namely, the unnecessary loss of the client is reduced, and meanwhile, better experience is brought to the client.

Further, the present invention also provides an HDMI port protection device, which includes a PCB board, wherein the above-mentioned HDMI port protection circuit 10 is disposed on the PCB board.

In summary, the HDMI port protection circuit and the HDMI port protection device provided by the present invention are connected to a motherboard, and the HDMI port protection circuit includes: the HDMI transmission module, the HDMI receiving module, the data input protection module and the data input module; the HDMI transmitting module is used for transmitting a data signal and a transmission voltage signal to the HDMI receiving module; the HDMI receiving module is used for transmitting the data signal to the data input module and transmitting the voltage signal to the data input protection module after receiving the data signal and the voltage signal; the data input protection module is used for pulling down the voltage of the data signal when detecting that the voltage signal is greater than a preset threshold value; the data input module is used for transmitting the pulled-down data signal to the mainboard. When the data input protection module detects that the voltage signal is greater than the preset threshold value, the voltage of the data signal is reduced, and the problem that the HDMI interface and the signal processing chip are damaged in overvoltage can be effectively solved.

It should be understood that the technical solutions and the inventive concepts according to the present invention may be equally replaced or changed by those skilled in the art, and all such changes or substitutions should fall within the protection scope of the appended claims.

Claims

1. The utility model provides a HDMI port protection circuit, with mainboard connection, its characterized in that, HDMI port protection circuit includes: the HDMI transmission module, the HDMI receiving module, the data input protection module and the data input module; the HDMI transmitting module is sequentially connected with the HDMI receiving module, the data input protection module, the data input module and the mainboard; the HDMI transmitting module is used for transmitting a data signal and a voltage signal to the HDMI receiving module; the HDMI receiving module is used for transmitting the data signal to the data input module and transmitting the voltage signal to the data input protection module after receiving the data signal and the voltage signal; the data input protection module is used for pulling down the voltage of the data signal when detecting that the voltage signal is greater than a preset threshold value; the data input module is used for transmitting the pulled-down data signal to the mainboard.

2. The HDMI port protection circuit of claim 1, wherein the data input protection module comprises: a control unit and a switch unit; the control unit and the switch unit are both connected with the HDMI receiving module, and the switch unit is also respectively connected with the data input module and the control unit; the control unit is used for generating a control voltage to the switch unit when detecting that the voltage signal is greater than the preset threshold value; the switch unit is used for normally working according to the control voltage.

3. The HDMI port protection circuit of claim 2, wherein the HDMI transmission module comprises: a first interface; the 2 nd pin, the 5 th pin, the 8 th pin, the 11 th pin, the 17 th pin, the 20 th pin, the 21 st pin, the 22 nd pin and the 23 rd pin of the first interface are all grounded, and the 1 st pin, the 3 rd pin, the 4 th pin, the 6 th pin, the 7 th pin, the 9 th pin, the 10 th pin, the 12 th pin, the 13 th pin, the 14 th pin, the 15 th pin, the 16 th pin, the 18 th pin and the 19 th pin of the first interface are all connected with the HDMI receiving module.

4. The HDMI port protection circuit of claim 3, wherein the HDMI reception module comprises: a second interface; the 2 nd pin, the 5 th pin, the 8 th pin, the 11 th pin, the 17 th pin, the 20 th pin, the 21 st pin, the 22 nd pin and the 23 rd pin of the second interface are all grounded, and the 1 st pin, the 3 rd pin, the 4 th pin, the 6 th pin, the 7 th pin, the 9 th pin, the 10 th pin, the 12 th pin, the 13 th pin, the 14 th pin, the 15 th pin, the 16 th pin, the 18 th pin and the 19 th pin of the second interface are correspondingly connected with the 1 st pin, the 3 rd pin, the 4 th pin, the 6 th pin, the 7 th pin, the 9 th pin, the 10 th pin, the 12 th pin, the 13 th pin, the 14 th pin, the 15 th pin, the 16 th pin, the 18 th pin and the 19 th pin of the first interface one to one; and the 18 th pin of the second interface is also connected with the data input protection module.

5. The HDMI port protection circuit of claim 4, wherein the control unit comprises: the circuit comprises a first resistor, a second resistor, a diode and a triode; a collector of the triode is connected with the pin 18 of the second interface, a base of the triode is connected with a cathode of the diode, an anode of the diode is connected with one end of the first resistor, and the other end of the first resistor is grounded; and the emitting electrode of the triode is respectively connected with one end of the second resistor and the switch unit, and the other end of the second resistor is grounded.

6. The HDMI port protection circuit of claim 5, wherein the switch unit comprises: the first switch tube and the second switch tube; the first end of the first switch tube and the first end of the second switch tube are both connected with one end of the second resistor and the emitter of the triode; the second end of the first switch tube is respectively connected with the 15 th pin of the second interface and the data input module, and the third end of the first switch tube is grounded; the second end of the second switch tube is connected with the 16 th pin of the second interface and the data input module, and the third end of the second switch tube is grounded.

7. The HDMI port protection circuit of claim 6, wherein the data input module comprises: a third resistor, a fourth resistor, a fifth resistor and a sixth resistor; one end of the third resistor and one end of the fourth resistor are connected with the 18 th pin of the second interface, the other end of the third resistor is connected with the 15 th pin of the second interface, the second end of the first switch tube and one end of the fifth resistor, the other end of the fifth resistor is connected with the main board, the other end of the fourth resistor is connected with the 16 th pin of the second interface, the second end of the second switch tube and one end of the sixth resistor, and the other end of the sixth resistor is connected with the main board.

8. The HDMI port protection circuit of claim 7, wherein the first switch tube is a first MOS tube, the first end of the first switch tube is a source of the first MOS tube, the second end of the first switch tube is a drain of the first MOS tube, and the third end of the first switch tube is a gate of the first MOS tube.

9. The HDMI port protection circuit of claim 6, wherein the second switch tube is a second MOS tube, a first end of the second switch tube is a source of the second MOS tube, a second end of the second switch tube is a drain of the second MOS tube, and a third end of the second switch tube is a gate of the second MOS tube.

10. An HDMI port protection device comprising a PCB board, wherein said PCB board is provided with an HDMI port protection circuit according to any one of claims 1-9.