An HDMI video source isolation protection device

Abstract

The utility model relates to an HDMI video source isolation protection device. The isolation protection device selects a suitable isolation scheme for different signals on an HDMI interface, thereby realizing isolation protection for the HDMI video source. The HDMI input part circuit comprises an HDMI input interface, ESD protection and an HDMI equalizer. After the HDMI video source is input through the HDMI input interface, it enters the equalizer for equalization processing, and the HDMI input interface is provided with ESD protection. The isolation circuit part comprises a high-voltage capacitor or a 10G network transformer, a magnetic isolator and an isolation power supply. After the signal of the HDMI video source passes through the equalizer, it enters the high-voltage capacitor and the magnetic isolator respectively, and the isolation power supply generates the power required on the isolation front and rear boards. After the signal of the HDMI video source is isolated, it passes through the ESD protection device and is output from the connector of the HDMI output interface.

Description

Technical Field

[0001] The utility model relates to the technical field of signal processing isolation, in particular to an HDMI video source isolation protection device. Background Art

[0002] HDMI interface, full name High Definition Multimedia Interface, is a fully digital video and audio transmission interface that can transmit uncompressed video and audio signals. As HDMI interface is widely used in various fields, the requirements for the stability, reliability and security of HDMI interface are getting higher and higher. Especially in medical imaging equipment, the price of HDMI video source equipment is relatively high, and the video source equipment is often damaged due to the display equipment, resulting in great economic losses.

[0003] Most of the existing HDMI isolation devices on the market convert HDMI into optical signals or network signals, and then transmit them to the display end through optical fiber or network cable. The display end then converts the optical signal or network signal into HDMI signal for display. This leads to problems such as large size, high cost and complex system of the conversion equipment. To address this problem, we have proposed an HDMI video source isolation protection device with small size, low cost and simple circuit. Summary of the invention

[0004] In order to solve the above technical problems, the utility model provides an HDMI video source isolation protection device, wherein the isolation protection device selects a suitable isolation scheme for different signals on the HDMI interface, thereby realizing isolation protection for the HDMI video source, and comprises an HDMI signal input part, an HDMI signal isolation part, and an HDMI signal output part, wherein the HDMI input part circuit comprises an HDMI input interface, ESD protection, and an HDMI equalizer; wherein the HDMI video source is input through the HDMI input interface, and then enters the equalizer for equalization processing, and the HDMI input interface is provided with ESD protection;

[0005] The isolation circuit part includes high-voltage capacitors, magnetic isolators and isolated power supplies. The signals of the HDMI video source enter the high-voltage capacitors and magnetic isolators after passing through the equalizer, and the isolated power supply generates the power required for the isolation front and rear boards.

[0006] The HMDI output part includes ESD protection and HDMI output interface; the signal of the HDMI video source after isolation passes through the ESD protection device and is output from the connector of the HDMI output interface.

[0007] In one embodiment of the present invention, ESD protection is provided in both the HDMI input interface and the HDMI output interface.

[0008] In one embodiment of the utility model, the HDMI signal isolation part processes TMDS signals, control signals, and power signals, wherein the high-voltage capacitor is a TMDS isolation device; the magnetic isolator is a control signal isolation device, and the isolated power supply is an isolated power supply module, wherein the TMDS isolation device may choose to use a 10G network transformer.

[0009] In one embodiment of the present invention, one end of the high-voltage capacitor is connected to the input TMDS signal, and the signal of each differential channel is connected to a 49.9 ohm resistor and pulled up to VCC3V3_1; the other end of the high-voltage capacitor is connected to the output TMDS signal, and the signal of each differential channel is connected to a 1.2K ohm resistor and pulled down to ground, where the ground is the isolated GND2.

[0010] The above technical solution of the utility model has the following advantages over the prior art: the isolation protection device described in the utility model does not require a complex signal conversion circuit, realizes the electrical isolation between the HDMI video source end and the display end, and has the characteristics of simple structure, small size, low cost, stable performance, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments of the utility model in combination with the accompanying drawings.

[0012] Figure 1 This is a block diagram of a high-voltage capacitor system based on an HDMI video source isolation protection device proposed by the utility model;

[0013] Figure 2 This is a system block diagram of a 10G network transformer based on an HDMI video source isolation protection device proposed by the utility model;

[0014] Figure 3 It is a high-voltage capacitor isolation circuit diagram of the TMDS signal on the HDMI interface in the utility model;

[0015] Figure 4 It is a 10G network transformer isolation circuit diagram based on TMDS signal on HDMI interface in the utility model;

[0016] Figure 5 The utility model discloses an isolation circuit diagram of a control signal DDC and a HPD signal on an HMDI interface. DETAILED DESCRIPTION Embodiment 1

[0017] like Figure 1As shown, this embodiment provides an HDMI video source isolation protection device, wherein the isolation protection device selects a suitable isolation scheme for different signals on the HDMI interface, thereby realizing isolation protection for the HDMI video source, and comprises an HDMI signal input part, an HDMI signal isolation part, and an HDMI signal output part, wherein the HDMI input part circuit comprises an HDMI input interface, ESD protection, and an HDMI equalizer; wherein the HDMI video source is input through the HDMI input interface, and then enters the equalizer for equalization processing, and the HDMI input interface is provided with ESD protection;

[0018] The isolation circuit part includes high-voltage capacitors, magnetic isolators and isolated power supplies. The signals of the HDMI video source enter the high-voltage capacitors and magnetic isolators after passing through the equalizer, and the isolated power supply generates the power required for the isolation front and rear boards.

[0019] The HMDI output part includes ESD protection and HDMI output interface; the signal of the HDMI video source after isolation passes through the ESD protection device and is output from the connector of the HDMI output interface.

[0020] Specifically, in the HDMI input part, considering that the HDMI interface is often plugged and unplugged with power on, the utility model adds ESD protection devices to reduce the risk of device damage caused by static electricity. Considering some application scenarios of long-distance transmission, the HDMI signal will be attenuated, and an equalizer is designed in the HDMI input part to ensure that the signal quality of the HDMI signal is optimal when entering the isolation circuit.

[0021] Figure 3 As shown, the isolation protection device described in this embodiment, wherein the isolation circuit part, for the three different signals on the HDMI interface: TMDS signal, control signal, power signal, the utility model adopts different isolation methods. When the TMDS signal transmits 1080P60 video, the rate is as high as 4.95Gbps. Ordinary magnetic isolation devices and optical coupler isolation cannot meet this rate. High-voltage capacitors are required for isolation. The four groups of high-voltage capacitors correspond to the four channels of the TMDS signal. One end of the high-voltage capacitor is connected to the input TMDS signal, and the signal of each differential channel is connected to a 49.9 ohm resistor and pulled up to VCC3V3_1. The other end of the high-voltage capacitor is connected to the output TMDS signal, and the signal of each differential channel is connected to a 1.2K ohm resistor and pulled down to the ground, where the ground is the isolated GND2. Furthermore, 2000VDC electrical isolation of the HDMI video source end and the display end is achieved.

[0022] like Figure 5As shown, the DDC signal uses the I2C protocol, and the I2C interface dedicated magnetic isolation chip ADuM1250 can be selected. The HPD signal is a unidirectional signal and a high and low level flag signal, and can also be completely isolated through the ADuM1250 chip. When the HDMI interface is used as an input interface, the 5V power supply on the interface is provided by an external device. In order to achieve complete isolation of the HDMI interface, it is necessary to pay attention to the isolation of the power supply during circuit design. Two isolation power modules are used in the utility model to convert the input power into the power required by the two parts of the circuit before and after isolation. Thereby achieving complete isolation of the power signal.

[0023] Regarding the HDMI output part, also considering that the HDMI output interface is often plugged in and out while powered, an ESD protection device is added in the utility model to reduce the risk of device damage caused by static electricity. Embodiment 2

[0024] like Figure 2 As shown, this embodiment provides an HDMI video source isolation protection device, wherein the isolation protection device selects a suitable isolation scheme for different signals on the HDMI interface, thereby realizing isolation protection for the HDMI video source, and is characterized in that it comprises an HDMI signal input part, an HDMI signal isolation part, and an HDMI signal output part, wherein the HDMI input part circuit comprises an HDMI input interface, ESD protection, and an HDMI equalizer; wherein the HDMI video source is input through the HDMI input interface, and then enters the equalizer for equalization processing, and at the same time, an ESD protection is provided in the HDMI input interface;

[0025] The isolation circuit part includes a network transformer, a magnetic isolator and an isolated power supply. The signal of the HDMI video source enters the network transformer and the magnetic isolator respectively after passing through the equalizer. At the same time, the isolated power supply generates the power required for the isolation front and rear boards.

[0026] The HMDI output part includes ESD protection and HDMI output interface; the signal of the HDMI video source after isolation passes through the ESD protection device and is output from the connector of the HDMI output interface.

[0027] In the HDMI input part, considering that the HDMI interface is often plugged and unplugged with power on, the utility model adds ESD protection devices to reduce the risk of device damage caused by static electricity. Considering some application scenarios of long-distance transmission, the HDMI signal will be attenuated, and an equalizer is designed in the HDMI input part to ensure that the signal quality of the HDMI signal is optimal when entering the isolation circuit.

[0028] In the isolation circuit part, the utility model adopts different isolation methods for the three different signals on the HDMI interface: TMDS signal, control signal, and power signal. When the TMDS signal transmits 1080P60 video, the rate is as high as 4.95Gbps. Ordinary magnetic isolation devices and optical coupler isolation cannot meet this rate. A 10G network transformer is required for isolation. The four differential channels of the 10G network transformer correspond to the four channels of the TMDS signal. Figure 4 As shown, the primary coil of the 10G network transformer is connected to the input TMDS signal, and the signal of each differential channel is connected across a 100 ohm resistor, and the center tap of the 10G network transformer is connected to VCC3V3_1 before isolation. The secondary coil of the 10G network transformer is connected to the output TMDS signal, and the center tap is connected in series with a 0.1uF capacitor to the ground, where the ground is GND2 after isolation. Specifically, 1500VDC electrical isolation is achieved between the HDMI video source end and the display end.

[0029] like Figure 5 As shown, the DDC signal uses the I2C protocol, and the I2C interface dedicated magnetic isolation chip ADuM1250 can be selected. The HPD signal is a unidirectional signal and a high and low level flag signal, and can also be completely isolated through the ADuM1250 chip. When the HDMI interface is used as an input interface, the 5V power supply on the interface is provided by an external device. In order to achieve complete isolation of the HDMI interface, it is necessary to pay attention to the isolation of the power supply during circuit design. Two isolation power modules are used in the utility model to convert the input power into the power required by the two parts of the circuit before and after isolation. Thereby achieving complete isolation of the power signal.

[0030] Regarding the HDMI output part, also considering that the HDMI output interface is often plugged in and out while powered, an ESD protection device is added in the utility model to reduce the risk of device damage caused by static electricity.

[0031] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the invention of the utility model.

Claims

1. An HDMI video source isolation protection device, characterized in that: It includes an HDMI signal input part, an HDMI signal isolation part, and an HDMI signal output part, wherein the HDMI input circuit includes an HDMI input interface, ESD protection, and an HDMI equalizer; wherein the HDMI video source is input through the HDMI input interface and then enters the equalizer for equalization processing, and the HDMI input interface is provided with ESD protection; The isolation circuit part includes high-voltage capacitors, magnetic isolators and isolated power supplies. The signals of the HDMI video source enter the high-voltage capacitors and magnetic isolators after passing through the equalizer, and the isolated power supply generates the power required for the isolation front and rear boards. The HMDI output part includes ESD protection and HDMI output interface; the signal of the HDMI video source after isolation passes through the ESD protection device and is output from the connector of the HDMI output interface.

2. The isolation protection device according to claim 1, characterized in that: The HDMI input interface and the HDMI output interface are both provided with ESD protection.

3. The isolation protection device according to claim 1, characterized in that: The HDMI signal isolation part processes TMDS signals, control signals, and power signals, wherein the high-voltage capacitor is a TMDS isolation device; the magnetic isolator is a control signal isolation device, and the isolated power supply is an isolated power supply module, wherein the TMDS isolation device may choose to use a 10G network transformer.

4. The isolation protection device according to claim 3, characterized in that: One end of the high-voltage capacitor is connected to the input TMDS signal, and the signal of each differential channel is connected to a 49.9 ohm resistor and pulled up to VCC3V3_1; the other end of the high-voltage capacitor is connected to the output TMDS signal, and the signal of each differential channel is connected to a 1.2K ohm resistor and pulled down to the ground, where the ground is the isolated GND2.

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