CN212063971U

CN212063971U - HDMI interface conversion circuit, drive integrated circuit board and electronic equipment

Info

Publication number: CN212063971U
Application number: CN202020297112.9U
Authority: CN
Inventors: 陈伟东
Original assignee: Guangzhou Shiyuan Electronics Thecnology Co Ltd; Guangzhou Shirui Electronics Co Ltd
Current assignee: Guangzhou Shiyuan Electronics Thecnology Co Ltd; Guangzhou Shirui Electronics Co Ltd
Priority date: 2020-03-11
Filing date: 2020-03-11
Publication date: 2020-12-01
Anticipated expiration: 2030-03-11

Abstract

The utility model relates to a HDMI interface converting circuit, drive integrated circuit board and electronic equipment. The utility model discloses a HDMI interface conversion circuit includes main chip, first switching circuit and second switching circuit, and main chip is equipped with first control end, second control end, power detection end, hot plug detection end, audio and video data input and audio and video data output; the first switching circuit conducts the VBUS end and the power supply or conducts the VBUS end and the power supply detection end according to the signal of the first control end; the hot plug detection end is connected with the HPD end of the HDMI and used for detecting or outputting a high level; the second switching circuit conducts the TMDS end and the audio and video data input end or conducts the TMDS end and the audio and video data output end according to a signal of the second control end. The utility model discloses a HDMI interface converting circuit can make the HMDI interface multiplexing in the electronic equipment be input or output interface.

Description

HDMI interface conversion circuit, drive integrated circuit board and electronic equipment

Technical Field

The utility model relates to an electronic circuit technical field especially relates to a HDMI interface conversion circuit, drive integrated circuit board and electronic equipment.

Background

A High Definition Multimedia Interface (HDMI) is a fully digital video and audio transmission Interface, which can transmit uncompressed audio and video signals. The HDMI can be used for set-top boxes, DVD players, personal computers, televisions, game hosts, comprehensive amplifiers, digital stereos, televisions and other electronic equipment. HDMI can send audio frequency and video signal simultaneously, because audio frequency and video signal adopt same wire rod, simplifies the installation degree of difficulty of system's circuit greatly.

Some business display complete machines, televisions and set-top boxes can be simultaneously provided with HDMI input and output interfaces, the HDMI input and output interfaces are completely the same in appearance or wire use, and the HDMI input and output interfaces cannot be multiplexed, so that the input or output interfaces are difficult to distinguish when the consumer actually uses the system, and the use is inconvenient.

SUMMERY OF THE UTILITY MODEL

Based on this, the utility model provides a HDMI interface converting circuit, drive integrated circuit board and electronic equipment can make the HMDI interface multiplexing in the electronic equipment be input or output interface.

In a first aspect, the utility model provides a HDMI interface converting circuit, include:

the main chip is provided with a first control end, a second control end, a power supply detection end, a hot plug detection end, an audio and video data input end and an audio and video data output end;

the first switching circuit is respectively connected with a power supply, the first control end, the power supply detection end and a VBUS end of an HDMI interface, and the first switching circuit conducts the VBUS end with the power supply or conducts the VBUS end with the power supply detection end according to a signal of the first control end;

the hot plug detection end is connected with the HPD end of the HDMI and used for detecting or outputting a high level;

the second switching circuit is respectively connected with the TMDS end of the HDMI, the second control end, the audio and video data input end and the audio and video data output end, and the second switching circuit conducts the TMDS end and the audio and video data input end or conducts the TMDS end and the audio and video data output end according to a signal of the second control end.

Optionally, the first switching circuit includes a first conducting switch and a second conducting switch;

the first conduction switch comprises a first input end, a first output end and a first drive end, the first drive end is connected with the first control end, the first input end is connected with the power supply, the first output end is connected with the VBUS end, and the first conduction switch switches the conduction state of the first input end and the first output end according to a signal of the first drive end;

the second conduction switch comprises a second input end, a second output end and a second driving end, the second driving end is connected with the first control end, the second input end is connected with the VBUS end, the second output end is connected with the power supply detection end, and the second conduction switch switches the conduction state of the second input end and the second output end according to a signal of the second driving end.

Optionally, the first conduction switch includes a first switch tube, the first driving end is a gate of the first switch tube, the first input end is a source of the first switch tube, and the first output end is a drain of the first switch tube.

Optionally, the first conduction switch includes a second switch tube, the second driving end is a gate of the second switch tube, the second input end is a drain of the second switch tube, and the second output end is a source of the second switch tube.

Optionally, the main chip further includes a level shift circuit, and an output end of the level shift circuit is connected to the first control end.

Optionally, the main chip further includes a first switch, a high level detection circuit, and a high level output circuit;

the stiff end of first change over switch with the hot plug detection end is connected, first change over switch's first expansion end with high level detection circuit connects, first change over switch's second expansion end with high level output circuit connects.

Optionally, the main chip further includes a power detection circuit, and an input end of the power detection circuit is connected to the power detection end.

Optionally, the switching circuit further includes a first resistor, and the first control end is connected to the first switching circuit through the first resistor.

In a second aspect, the present invention provides a driving board, including the first aspect of this application implementation HDMI interface converting circuit.

In a third aspect, the present invention provides an electronic device, including:

the HDMI interface and the driving board card are used for implementing the second aspect of the application;

the first switching circuit is respectively connected with a power supply, a first control end, a power supply detection end and a VBUS end of an HDMI interface, and the first switching circuit conducts the VBUS end and the power supply or conducts the VBUS end and the power supply detection end according to a signal of the first control end;

The utility model discloses in, make the power end of HDMI port can switch into input or output state through first switching circuit, make the data end of HDMI port can switch into input or output state through the second switching circuit to and set up the HPD end into can detecting or export the high level, thereby make same HDMI port can switch into input state or output state, realized the multiplexing of HDMI port, made things convenient for user's use.

For better understanding and implementation, the technical solutions of the present invention are described in detail below with reference to the accompanying drawings.

Drawings

Fig. 1 is a schematic diagram of an HDMI interface conversion circuit according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a HDMI interface conversion circuit according to another embodiment of the present invention;

fig. 3 is a schematic diagram of a HDMI interface conversion circuit according to still another embodiment of the present invention;

fig. 4 is a schematic structural view of a driving board card in an embodiment of the present invention;

fig. 5 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some but not all of the relevant portions of the present invention are shown in the drawings.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, are not to be construed as limiting the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

In the following, several specific embodiments are given for describing the technical solution of the present application in detail. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

Fig. 1 is an HDMI interface conversion circuit structure diagram in this application's an exemplary embodiment, the utility model provides an HDMI interface conversion circuit includes main chip 1, first switching circuit 2 and second switching circuit 3, main chip 1 is equipped with first control end 11, second control end 12, power detection end 13, hot plug detection end 14, audio and video data input 15 and audio and video data output 16.

The main chip 1 is used as a main control chip in electronic equipment, and usually integrates an analog decoder, a digital decoder, a demodulator, a central processing unit and an image processing unit, and may have rich peripheral interfaces. The main chip 1 can be connected with different operating systems through a channel selector switch, and transmits audio and video signals transmitted by the different operating systems to a screen and a loudspeaker for audio and video playing after decoding the audio and video signals. In the present invention, the main chip 1 is integrated with a related circuit as an HDMI source device and an HDMI sink device.

The first switching circuit 2 is respectively connected to a 5V power supply, a first control terminal 11, a power supply detection terminal 13, and a VBUS terminal of the HDMI interface 4, and the first switching circuit 2 switches on the VBUS terminal and the 5V power supply, or switches on the VBUS terminal and the power supply detection terminal 13, according to a signal of the first control terminal 11.

For the HDMI source device in the prior art, the VBUS terminal is a power supply terminal that supplies power to the external HDMI source device with a 5V power supply, and for the HDMI sink device in the prior art, the VBUS terminal is a power supply detection terminal that detects the power supply of the 5V power supply provided by the external HDMI sink device.

When the first switching circuit 2 switches on the VBUS terminal and the 5V power supply according to the signal of the first control terminal 11, the VBUS terminal is used as a power supply terminal, that is, the HDMI port 4 is switched to an output mode. When the first switching circuit 2 switches on the VBUS terminal and the power detection terminal 13 according to the signal of the first control terminal 11, the VBUS terminal is used as the power detection terminal, that is, the HDMI port 4 is switched to the input mode.

In practical applications, the switching circuit 2 may implement different conduction relationships between the VBUS terminal and the 5V power supply or the power supply detection terminal 13 according to different high and low levels output by the first control terminal 11, for example, when the first control terminal 11 outputs a high level, the first switching circuit 2 conducts the VBUS terminal and the 5V power supply, and when the first control terminal 11 outputs a low level, the first switching circuit 2 conducts the VBUS terminal and the power supply detection terminal 13.

The first switching circuit 2 may be any switching circuit that implements the above switching function in the prior art, for example, the switching circuit may be implemented by a switch, a switching chip, or a switching circuit that combines a plurality of different electronic components, and in a specific example, the switching circuit may be implemented by a combination of switching devices such as a switching tube and a transistor.

The hot plug detection end 14 is connected with the HPD end of the HDMI interface 4, and is configured to detect or output a high level.

For the HDMI receiving device in the prior art, the HPD (hot plug and detect) terminal outputs a high level to the external HDMI source device after the VBUS terminal detects the 5V power output by the external HDMI source device, and for the HDMI source device in the prior art, the HPD terminal is configured to detect a high level signal output by the HPD terminal of the external HDMI receiving device.

Therefore, in the present invention, the hot plug detection end 14 can be used to detect or output high level, so as to be able to detect high level when the HDMI interface 4 is used as HDMI output interface, and output high level when the HDMI interface 4 is used as HDMI input interface after the VBUS end detects the 5V power supply of the external HDMI output interface.

The second switching circuit 3 is respectively connected with the TMDS terminal of the HDMI interface 4, the second control terminal 12, the audio/video data input terminal 15, and the audio/video data output terminal 16, and the second switching circuit 3 switches on the TMDS terminal 43 and the audio/video data input terminal 15 or switches on the TMDS terminal 43 and the audio/video data output terminal 16 according to a signal of the second control terminal 12.

Aiming at an HDMI input or output interface in the prior art, the TMDS end is a TMDS BUS for transmitting audio and video data, and specifically comprises a plurality of pairs of TMDS data terminals.

When the second switching circuit 3 switches on the TMDS terminal and the audio/video data input terminal 15 according to the signal of the second control terminal 12, the audio/video data input terminal 15 receives an audio/video signal output by an external HDMI output interface. When the second switching circuit 3 switches on the TMDS terminal and the audio/video data output terminal 16 according to the signal of the second control terminal 12, the audio/video data output terminal 16 outputs an audio/video signal to an external HDMI input interface.

In practical applications, the second switching circuit 3 may implement different conduction relationships between the TMDS terminal and the audio/video data input terminal 15 or the audio/video data output terminal 16 according to different high and low levels output by the second control terminal 12, for example, when the second control terminal 12 outputs a high level, the second switching circuit 3 conducts the TMDS terminal and the audio/video data input terminal 15, and when the second control terminal 12 outputs a low level, the second switching circuit 3 conducts the TMDS terminal and the audio/video data output terminal 16.

The second switching circuit 3 may be any switching circuit that implements the above switching function in the prior art, for example, the switching circuit may be implemented by a switch, a switching chip, or a switching circuit that combines a plurality of different electronic components, and in a specific example, the switching circuit may be implemented by a combination of switching devices such as a switching tube and a transistor.

The working process of the embodiment is as follows:

when an HDMI source device is inserted into the HDMI interface 4, if the first switching circuit 2 is switched to a state of connecting the VBUS terminal and the 5V power supply at this time, the hot plug detection terminal 14 is in an input detection mode; since the HPD terminal of the HDMI source device does not output a high level, the main chip 1 does not respond.

When the first switching circuit 2 is switched to a state of turning on the VBUS terminal and the power detection terminal 13, the power detection terminal 13 detects a 5V voltage from the HDMI source device, and the main chip 1 enters an HDMI sink device mode, in which the following operations are continued:

(1) the second switching circuit 3 conducts the TMDS end and the audio and video data input end 15;

(2) the hot plug detection terminal 14 outputs a high level and performs an HDMI handshake operation through ddc (scl sda);

(3) the utility model discloses a display device at HDMI interface converting circuit place normally shows received audio and video signal through the picture.

When an HDMI sink device is inserted into the HDMI interface 4, if the first switching circuit 1 is switched to a state where the VBUS terminal and the power detection terminal 13 are turned on at this time, the power detection terminal 13 cannot detect the 5V voltage because the VBUS terminal of the HDMI sink device does not output the 5V voltage.

When the first switching circuit is switched to connect the VBUS terminal and the 5V power supply, the hot plug detection terminal 14 is switched to detect a high level, and since the HPD terminal of the HDMI receiving device outputs a high level, the hot plug detection terminal 14 will detect a high level, and the main chip 1 enters an HDMI source device mode, and the following actions are continued in this mode:

(1) the second switching circuit 3 conducts the TMDS end and the audio/video data output end 16;

(2) the hot plug detection end 14 reads the EDID of the HDMI receiving device and completes the handshake operation;

(3) and outputting the audio and video signals to the HDMI receiving equipment.

As shown in fig. 2, in a specific example, the first switching circuit 2 includes a first on switch 21 and a second on switch 22.

The first conduction switch 21 includes a first input terminal 211, a first output terminal 212 and a first driving terminal 213, the first driving terminal 213 is connected to the first control terminal 11, the first input terminal 211 is connected to the 5V power supply, the first output terminal 212 is connected to the VBUS terminal, and the first conduction switch 21 switches conduction states of the first input terminal 211 and the first output terminal 212 according to a signal of the first driving terminal 213.

The second conduction switch 22 includes a second input terminal 221, a second output terminal 222 and a second driving terminal 223, the second driving terminal 223 is connected to the first control terminal 11, the second input terminal 221 is connected to the VBUS terminal, the second output terminal 222 is connected to the power detection terminal 13, and the second conduction switch 22 switches conduction states of the second input terminal 221 and the second output terminal 222 according to a signal of the second driving terminal 223.

In a specific example, as shown in fig. 3, the first conducting switch includes a first switch Q1, the first driving terminal is a gate of the first switch Q1, the first input terminal is a source of the first switch Q1, and the first output terminal is a drain of the first switch Q1. The second conducting switch includes a second switch Q2, the second driving terminal is a gate of the second switch Q2, the second input terminal is a drain of the second switch Q2, and the second output terminal is a source of the second switch Q2. Specifically, the first switching transistor Q1 may be a P-channel fet, and the second switching transistor Q2 may be an N-channel fet.

In an exemplary embodiment, the first control terminal 11 may be an output signal that manually or automatically switches between high and low levels according to a set rule, for example, may be an interval setting time to switch between high and low levels, specifically, the interval time may be 1 second, and when detecting that an HDMI source device or an HDMI sink device is inserted into the HDMI interface 4, the switching is suspended.

In an example, the first control terminal 11 may be connected to a level shift circuit disposed on the main chip 1, and the level shift circuit is used to regularly switch between high and low levels of the output signal.

In another example, as shown in fig. 3, a CPU17 is further disposed on the main chip 1, and the CPU17 is connected to the first control terminal 11 and is configured to output a regularly switched high-low level signal to the first control terminal 11.

In an embodiment, the function switching of the hot plug detection terminal 14 to detect or output a high level may be synchronous switching with the output of the first control terminal 11, and the specific implementation of this switching function may be synchronous switching between the output of the first control terminal 11 and the hot plug detection terminal 14 implemented by using an associated interlock circuit inside or outside a main chip. The HPD end function switching may also be switching to output a high level after the VBUS end detects a 5V power supply of the external HDMI output interface, that is, when the power supply detection end 13 detects a 5V voltage signal, the hot plug detection end outputs a high level.

The interlock circuit for switching the functions of the hot plug detection terminal 14 may be implemented by driving a switch through an output signal of the first control terminal 11, an output signal of the CPU17, an output signal of the level shift circuit, or an input signal of the hot plug detection terminal 14, for example, in an optional example, the main chip further includes a first switch, a high level detection circuit, and a high level output circuit; the stiff end of first change over switch with the hot plug detection end is connected, first change over switch's first expansion end with high level detection circuit connects, first change over switch's second expansion end with high level output circuit connects. The realization mode is various, the utility model discloses in, do not do specifically and restrict.

In an exemplary embodiment, the switching of the output signal of the second control terminal 12 may also be realized by driving the output signal of the first control terminal 11, the output signal of the CPU17, the output signal of the level shift circuit, or the input signal of the hot plug detection terminal 14.

In an exemplary embodiment, the main chip further includes a power detection circuit, and an input terminal of the power detection circuit is connected to the power detection terminal.

In an exemplary embodiment, as shown in fig. 3, the HDMI interface converting circuit further includes a first resistor R1, and the first control terminal is connected to the first switching circuit through the first resistor R1.

In one example, as shown in fig. 3, the second switching circuit 3 is an HDMI signal switching module.

Fig. 4 is a schematic structural diagram of the driving board card provided by the present invention. The drive board card 400 comprises the embodiment of the present invention provides an arbitrary HDMI interface conversion circuit.

Fig. 5 is a schematic structural diagram of an electronic device provided in the present application, where the electronic device 500 includes an HDMI interface 4 and any one of the driving boards 400 provided in the present application, where the first switching circuit 2 is respectively connected to a power supply, a first control terminal 11, a power detection terminal 13, and a VBUS terminal of the HDMI interface 4, and the first switching circuit 2 conducts the VBUS terminal of the HDMI interface 4 and the power supply or conducts the VBUS terminal of the HDMI interface 4 and the power detection terminal 13 according to a signal of the first control terminal 11;

the hot plug detection end 13 is connected with the HPD end of the HDMI interface 4 and is used for detecting or outputting a high level;

the second switching circuit 3 is respectively connected with the TMDS terminal of the HDMI interface 4, the second control terminal 12, the audio/video data input terminal 15, and the audio/video data output terminal 16, and the second switching circuit 3 switches on the TMDS terminal and the audio/video data input terminal 15 or switches on the TMDS terminal and the audio/video data output terminal 16 according to a signal of the second control terminal 12.

Specifically, in a possible implementation manner, the electronic device is an intelligent interactive tablet.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention.

Claims

1. An HDMI interface conversion circuit, comprising:

2. The HDMI interface conversion circuit of claim 1, wherein:

the first switching circuit comprises a first conducting switch and a second conducting switch;

3. The HDMI interface conversion circuit of claim 2, wherein:

the first conduction switch comprises a first switch tube, the first driving end is a grid electrode of the first switch tube, the first input end is a source electrode of the first switch tube, and the first output end is a drain electrode of the first switch tube.

4. The HDMI interface conversion circuit of claim 2, wherein:

the second conduction switch comprises a second switch tube, the second driving end is a grid electrode of the second switch tube, the second input end is a drain electrode of the second switch tube, and the second output end is a source electrode of the second switch tube.

5. The HDMI interface conversion circuit according to any one of claims 1 to 4, wherein:

the main chip further comprises a level conversion circuit, and the output end of the level conversion circuit is connected with the first control end.

6. The HDMI interface conversion circuit according to any one of claims 1 to 4, wherein:

the main chip also comprises a first selector switch, a high level detection circuit and a high level output circuit;

7. The HDMI interface conversion circuit according to any one of claims 1 to 4, wherein:

the main chip further comprises a power supply detection circuit, and the input end of the power supply detection circuit is connected with the power supply detection end.

8. The HDMI interface conversion circuit according to any one of claims 1 to 4, wherein:

the first control end is connected with the first switching circuit through the first resistor.

9. A drive integrated circuit board, its characterized in that:

an HDMI interface conversion circuit according to any of claims 1 to 8.

10. An electronic device, characterized in that:

the drive board card comprises an HDMI interface and the drive board card of claim 9;

the first switching circuit is respectively connected with a power supply, a first control end, a power supply detection end and a VBUS end of an HDMI (high definition multimedia interface), and the first switching circuit conducts the VBUS end and the power supply or conducts the VBUS end and the power supply detection end according to a signal of the first control end;