CN109101204B - Signal transmission circuit and communication system using same - Google Patents

Abstract

A signal transmission circuit is connected between a display and a host, the signal transmission circuit includes a switch module and an adjustment module, the switch module is connected between the display and the host, the adjustment module It is used to adjust the capacitive reactance between the display and the host. When the display is connected to the host, the adjustment module outputs a voltage signal to the switch module to control the switch module to conduct, so as to Communication between the display and the host is enabled. The present invention also provides a communication system applying the signal transmission circuit. In this way, the quality of the signal transmitted between the display and the host can be improved, and the cost can also be saved.

Description

Signal transmission circuit and communication system using the same

technical field

The present invention relates to a signal transmission circuit and a communication system using the signal transmission circuit.

Background technique

The Display Data Channel (DDC) is an information channel established between the host and the monitor, and determines whether the two-way communication between the monitor and the host can proceed smoothly.

The traditional design of the display data channel circuit uses two diodes in series. However, the high power consumption of the diodes will increase the design cost, and will also occupy the space of the motherboard, which is not conducive to the layout of other components on the motherboard.

SUMMARY OF THE INVENTION

In view of the above, it is necessary to provide a signal transmission circuit and a communication system using the signal transmission circuit.

A signal transmission circuit is connected between a display and a host, the signal transmission circuit includes a switch module and an adjustment module, the switch module is connected between the display and the host, the adjustment module It is used to adjust the capacitive reactance between the display and the host. When the display is connected to the host, the adjustment module outputs a voltage signal to the switch module to control the switch module to conduct, so as to Communication between the display and the host is enabled.

Further, the display includes a first communication pin and a second communication pin, the host includes a high-definition multimedia interface, and the high-definition multimedia interface includes a first communication pin and a second communication pin. communication pins, the switch module includes a first electronic switch and a first resistor, the adjustment module includes a Schottky diode and a second resistor, the first end of the first electronic switch is connected to a first power supply, The second end of the first electronic switch is connected to the first communication pin of the display, the second end of the first electronic switch is also connected to the first power supply through the first resistor, and the first The third end of an electronic switch is connected to the first communication pin of the high-definition multimedia interface, and the third end of the first electronic switch is also connected to the first communication pin of the Schottky diode through the second resistor. an output terminal, the input terminal of the Schottky diode is connected to a second power supply.

Further, the switch module further includes a second electronic switch and a third resistor, the first end of the second electronic switch is connected to the first power supply, and the second end of the second electronic switch is connected to the The second communication pin of the display, the second end of the second electronic switch is also connected to the first power supply through the third resistor, and the third end of the second electronic switch is connected to the high The second communication pin of the high-definition multimedia interface, and the third end of the second electronic switch is also connected to the second output end of the Schottky diode through a fourth resistor.

Further, the first electronic switch and the second electronic switch are both N-type field effect transistors.

Further, the first terminal to the third terminal of the first electronic switch correspond to the gate, the source and the drain of the N-type field effect transistor.

Further, the first end to the third end of the second electronic switch correspond to the gate electrode, the source electrode and the drain electrode of the N-type field effect transistor.

A communication system, the communication system includes a display, a signal transmission circuit and a host, the signal transmission circuit is connected between the display and the host, the signal transmission circuit includes a switch module and a regulator The switch module is connected between the display and the host, and the adjustment module is used to adjust the capacitive reactance between the display and the host. When the display is connected to the host, the The adjustment module outputs a voltage signal to the switch module to control the switch module to be turned on, so as to communicate between the display and the host.

Further, the display includes a first communication pin and a second communication pin, the host includes a high-definition multimedia interface, and the high-definition multimedia interface includes a first communication pin and a second communication pin. communication pins, the switch module includes a first electronic switch and a first resistor, the adjustment module includes a Schottky diode and a second resistor, the first end of the first electronic switch is connected to a first power supply, The second end of the first electronic switch is connected to the first communication pin of the display, the second end of the first electronic switch is also connected to the first power supply through the first resistor, and the first The third end of an electronic switch is connected to the first communication pin of the high-definition multimedia interface, and the third end of the first electronic switch is also connected to the first communication pin of the Schottky diode through the second resistor. an output terminal, the input terminal of the Schottky diode is connected to a second power supply.

Further, the switch module further includes a second electronic switch and a third resistor, the first end of the second electronic switch is connected to the first power supply, and the second end of the second electronic switch is connected to the The second communication pin of the display, the second end of the second electronic switch is also connected to the first power supply through the third resistor, and the third end of the second electronic switch is connected to the high The second communication pin of the high-definition multimedia interface, and the third end of the second electronic switch is also connected to the second output end of the Schottky diode through a fourth resistor.

Further, the first electronic switch and the second electronic switch are both N-type field effect transistors, and the first to third terminals of the first electronic switch and the second resistance switch are all corresponding to the N The gate, source and drain of the type FET.

The signal transmission circuit of the present invention and the communication system using the signal transmission circuit can control the conduction of the switch module according to the connection between the display and the high-definition multimedia interface, thereby enabling the display to communicate with the high-definition multimedia interface. The host communicates information. In this way, the quality of the signal transmitted between the display and the host can be improved, and the cost can also be saved.

Description of drawings

FIG. 1 is a block diagram of a preferred embodiment of the communication system of the present invention.

FIG. 2 is a circuit diagram of the signal transmission circuit connection shown in FIG. 1 and between the display and the host.

Description of main component symbols

Communication Systems 100

Monitor 10

Signal Transmission Circuit 20

switch module 22

Host 30

High-Definition Multimedia Interface 32

Schottky diode D1

The first electronic switch Q1

Second electronic switch Q2

The first resistor to the fourth resistor R1-R4

The following specific embodiments will further illustrate the present invention in conjunction with the above drawings.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments.

In order to make the purpose, technical solutions and advantages of the present invention clearer, the following will further describe and describe the signal transmission circuit in the present invention and the communication system using the signal transmission circuit in detail with reference to the accompanying drawings and embodiments.

As shown in FIG. 1 , a preferred embodiment of the present invention provides a communication system 100 . The communication system 100 includes a display 10 , a signal transmission circuit 20 and a host 30 .

In one embodiment, the signal transmission circuit 20 is connected between the display 10 and the host 30 to implement communication between the display 10 and the host 30 .

The display 10 communicates Extended Display Identification Data (EDID) information with the host 30 through the signal transmission circuit 20 . The EDID information includes resolution, refresh rate, and color.

In one embodiment, the host 30 is a computer host.

As shown in FIG. 2 , the display 10 includes a first communication pin DDPD_CTRLCLK and a second communication pin DDPD_CTRLDATA.

The host 30 includes a High Definition Multimedia Interface (HDMI) 32, and the high definition multimedia interface 32 includes a first communication pin HDMID_CTRL_CLK and a second communication pin HDMID_CTRL_DATA.

The signal transmission circuit 20 includes a switch module 22 and a regulation module. The switch module 22 includes a first electronic switch Q1, a second electronic switch Q2, a first resistor R1 and a third resistor R3, and the adjustment module includes a Schottky diode D1, a second resistor R2 and a fourth resistor R4. The first end of the first electronic switch Q1 is connected to a +3P3V power supply, the second end of the first electronic switch Q1 is connected to the first communication pin DDPD_CTRLCLK of the display 10, and the first electronic switch Q1 The second end of the first electronic switch Q1 is also connected to the +3P3V power supply through the first resistor R1, and the third end of the first electronic switch Q1 is connected to the first communication pin HDMID_CTRL_CLK of the high-definition multimedia interface 32, so The third terminal of the first electronic switch Q1 is also connected to the first output terminal of the Schottky diode D1 through the third resistor R3, and the input terminal of the Schottky diode D1 is connected to a +5V power supply.

The first end of the second electronic switch Q2 is connected to the +3P3V power supply, the second end of the second electronic switch Q2 is connected to the second communication pin DDPD_CTRLDATA of the display 10, and the second electronic switch The second end of Q2 is also connected to the +3P3V power supply through the second resistor R2, and the third end of the second electronic switch Q2 is connected to the second communication pin HDMID_CTRL_DATA of the high-definition multimedia interface 32, The third terminal of the second electronic switch Q2 is also connected to the second output terminal of the Schottky diode D1 through the fourth resistor R4.

In one embodiment, the first electronic switch Q1 and the second electronic switch Q2 are both N-FETs.

The first terminal to the third terminal of the first electronic switch Q1 are all corresponding to the gate, source and drain of the NFET.

The first terminal to the third terminal of the second electronic switch Q2 correspond to the gate, source and drain of the NFET.

The Schottky diode D1 can be used to adjust the capacitive reactance between the display 10 and the host 30 , and the Schottky diode D1 can also prevent the current of the display 10 from flowing back.

When the high-definition multimedia interface 32 of the host 30 is connected to the display 10, the first output terminal and the second output terminal of the Schottky diode D1 respectively output voltage signals to the output terminals of the first electronic switch Q1. The third terminal and the third terminal of the second electronic switch Q2, at this time, the voltage of the first terminal of the first electronic switch Q1 is greater than the voltage of the second terminal of the first electronic switch Q1, the first electronic switch Q1 is turned on, the voltage of the first terminal of the second electronic switch Q2 is greater than the voltage of the second terminal of the second electronic switch Q2, and the second electronic switch Q2 is turned on. In this way, the display 10 can communicate EDID information with the host 30 .

When the display 10 is connected to the high-definition multimedia interface 32 , the switch module 22 is correspondingly controlled to be turned on, thereby enabling the display 10 to communicate EDID information with the host 30 . In this way, the quality of the signal transmitted between the display 10 and the host 30 can be improved, and the cost can also be saved.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Those skilled in the art should understand that the technical solutions of the present invention may be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts will fall within the protection scope of the present invention.

Claims (8)

1. A signal transmission circuit, connected between a display and a host, wherein the signal transmission circuit comprises a switch module and an adjustment module, and the switch module is connected between the display and the host. During the time, the adjustment module is used to adjust the capacitive reactance between the display and the host, and when the display is connected to the host, the adjustment module outputs a voltage signal to the switch module to control the The switch module is turned on, so as to communicate between the display and the host; the display includes a first communication pin and a second communication pin, the host includes a high-definition multimedia interface, the The high-definition multimedia interface includes a first communication pin and a second communication pin, the switch module includes a first electronic switch and a first resistor, and the adjustment module includes a Schottky diode and a second resistor, The first end of the first electronic switch is connected to the first power supply, the second end of the first electronic switch is connected to the first communication pin of the display, and the second end of the first electronic switch is also connected through The first resistor is connected to the first power supply, the third end of the first electronic switch is connected to the first communication pin of the high-definition multimedia interface, and the third end of the first electronic switch is also The second resistor is connected to the first output terminal of the Schottky diode, and the input terminal of the Schottky diode is connected to a second power supply. 2 . The signal transmission circuit of claim 1 , wherein the switch module further comprises a second electronic switch and a third resistor, and a first end of the second electronic switch is connected to the first electronic switch. 3 . a power supply, the second end of the second electronic switch is connected to the second communication pin of the display, and the second end of the second electronic switch is also connected to the first power supply through the third resistor, so The third end of the second electronic switch is connected to the second communication pin of the high-definition multimedia interface, and the third end of the second electronic switch is also connected to the Schottky diode through a fourth resistor. second output. 3 . The signal transmission circuit of claim 2 , wherein the first electronic switch and the second electronic switch are both N-type field effect transistors. 4 . 4 . The signal transmission circuit of claim 3 , wherein the first terminal to the third terminal of the first electronic switch correspond to the gate, source and drain of the N-type field effect transistor. 5 . . 5 . The signal transmission circuit of claim 4 , wherein the first terminal to the third terminal of the second electronic switch correspond to the gate, source and drain of the N-type field effect transistor. 6 . . 6. A communication system, characterized in that the communication system comprises a display, a signal transmission circuit and a host, the signal transmission circuit is connected between the display and the host, and the signal transmission circuit comprises A switch module and an adjustment module, the switch module is connected between the display and the host, the adjustment module is used to adjust the capacitive reactance between the display and the host, when the display and the host When the host is connected, the adjustment module outputs a voltage signal to the switch module to control the switch module to be turned on, so as to communicate between the display and the host; the display includes a first communication lead. pin and a second communication pin, the host includes a high-definition multimedia interface, the high-definition multimedia interface includes a first communication pin and a second communication pin, the switch module includes a first an electronic switch and a first resistor, the adjustment module includes a Schottky diode and a second resistor, the first end of the first electronic switch is connected to the first power supply, and the second end of the first electronic switch is connected to the The first communication pin of the display, the second end of the first electronic switch is also connected to the first power supply through the first resistor, and the third end of the first electronic switch is connected to the high The first communication pin of the high-definition multimedia interface, the third end of the first electronic switch is also connected to the first output end of the Schottky diode through the second resistor, and the input of the Schottky diode The terminal is connected to a second power source. 7 . The communication system according to claim 6 , wherein the switch module further comprises a second electronic switch and a third resistor, and a first end of the second electronic switch is connected to the first power source. 8 . , the second end of the second electronic switch is connected to the second communication pin of the display, the second end of the second electronic switch is also connected to the first power supply through the third resistor, the The third end of the second electronic switch is connected to the second communication pin of the high-definition multimedia interface, and the third end of the second electronic switch is also connected to the third end of the Schottky diode through a fourth resistor. Two output terminals. 8. The communication system of claim 7, wherein the first electronic switch and the second electronic switch are both N-type field effect transistors, and the first electronic switch and the second resistance switch are The first end to the third end correspond to the gate electrode, the source electrode and the drain electrode of the N-type field effect transistor.

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