CN115866174B - HDMI protection board circuit, HDMI protection board and device - Google Patents
HDMI protection board circuit, HDMI protection board and device Download PDFInfo
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- CN115866174B CN115866174B CN202211575943.8A CN202211575943A CN115866174B CN 115866174 B CN115866174 B CN 115866174B CN 202211575943 A CN202211575943 A CN 202211575943A CN 115866174 B CN115866174 B CN 115866174B
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Abstract
本发明公开了一种HDMI防护板电路、HDMI防护板以及装置，HDMI防护板电路包括：电源防护电路、多个共模电感模块、热拔插拉低电路、显示数据通道阻抗匹配电路和消费电子控制拉高电路；电源防护电路、共模电感模块、热拔插拉低电路、显示数据通道阻抗匹配电路和消费电子控制拉高电路各自连接在HDMI公头和HDMI端口之间；所述共模电感模块用于滤除HDMI差分线上的共模干扰。从而,本发明能够实现通过滤除共模干扰和固定频率的干扰，从而，提升HDMI接口的防护性能。
The present invention discloses an HDMI protection board circuit, an HDMI protection board and a device. The HDMI protection board circuit includes: a power protection circuit, multiple common mode inductor modules, a hot plug pull-down circuit, a display data channel impedance matching circuit and a consumer electronics control pull-up circuit; the power protection circuit, the common mode inductor module, the hot plug pull-down circuit, the display data channel impedance matching circuit and the consumer electronics control pull-up circuit are respectively connected between the HDMI male head and the HDMI port; the common mode inductor module is used to filter out the common mode interference on the HDMI differential line. Therefore, the present invention can improve the protection performance of the HDMI interface by filtering out the common mode interference and the fixed frequency interference.
Description
Technical Field
The invention relates to the technical field of multimedia, in particular to an HDMI protection plate circuit, an HDMI protection plate and a device.
Background
With the development of technology, HDMI is a fully digital audio-visual transmission interface, which supports the transmission of high-resolution video streams and high-fidelity audio streams, greatly reduces the complexity of wiring, and is widely applied to consumer electronic devices such as televisions, players, personal computers, digital audio devices and the like.
However, in the HDMI devices of the prior art, protection measures are ignored in terms of how to increase the data amount of the HDMI devices, and only TVS tubes are added to all ports of the HDMI to prevent ESD (Electro-STATIC DISCHARGE, electrostatic discharge) problems, that is, only the influence of static electricity on the data line is prevented, and the interference of common mode signals on differential mode signals is ignored to cause the signals on the differential pair to be interfered, so that the HDMI interface and the rear circuit are unstable and cause data instability, and the circuit is damaged easily due to external interference.
In summary, none of the HDMI devices of the conventional art should have a perfect protection scheme.
Disclosure of Invention
The invention mainly aims to provide an HDMI protection plate circuit, an HDMI protection plate and a device, which aim to solve the problems that clutter and current reverse irrigation at a power supply input end are prevented by filtering common mode interference and fixed frequency interference which occur during data line transmission in an HDMI interface, and meanwhile, the problems that CEC, DDC and hot plug interfaces are unstable in state and easy to trigger by mistake during no signal transmission are prevented, so that the protection performance of the HDMI interface is improved.
In order to achieve the above purpose, the invention provides an HDMI protection plate circuit, which is connected between an HDMI male head and an HDMI port, and comprises a power supply protection circuit, a plurality of common mode inductance modules, a hot plug pull-down circuit, a display data channel impedance matching circuit and a consumer electronics control pull-up circuit;
the power protection circuit, the common mode inductance module, the hot plug pull-down circuit, the display data channel impedance matching circuit and the consumer electronics control pull-up circuit are respectively connected between the HDMI male head and the HDMI port;
the power supply protection circuit is used for eliminating the interference of fixed frequency on a power line and preventing the reverse current filling of the HDMI port;
the common mode inductance module is used for filtering common mode interference on the HDMI differential line;
the hot-plug low-voltage circuit is used for keeping a low-level stable state and filtering high-frequency clutter;
the consumer electronic control pull-up circuit is used for keeping a high-level stable state;
The display data channel impedance matching circuit is used for impedance matching of the signal lines and absorbing reflected signals.
Optionally, the power protection circuit is connected between a power input pin of the HDMI male head and a power input pin of the HDMI port;
The common mode inductance modules are connected between the data differential signal pins of the HDMI male heads and the data differential signal pins of the HDMI ports respectively;
the common mode inductance module is connected between the clock differential signal pin of the HDMI male head and the clock differential signal pin of the HDMI port;
The hot plug low circuit is connected between a hot plug signal pin of the HDMI male head and a hot plug signal pin of the HDMI port;
The first end of the consumer electronic control pull-up circuit is connected with a CEC control signal pin of the HDMI male head, and the second end of the consumer electronic control pull-up circuit is respectively connected with a power input pin and a CEC control signal pin of the HDMI port;
The display data channel impedance matching circuit is connected between the serial pin of the HDMI male head and the serial pin of the HDMI port.
Optionally, the power protection circuit comprises a first diode and magnetic beads;
The first diode and the magnetic beads are connected in parallel between a power input pin of the HDMI male head and a power input pin of the HDMI port;
the magnetic beads are used for eliminating interference of fixed frequency on the power line;
The first diode is used for preventing the reverse current filling of the HDMI port.
Optionally, the common mode inductance module comprises a common mode inductance;
The common mode inductor is connected between the data differential signal pin of the HDMI male head and the data differential signal pin of the HDMI port;
the common mode inductor is used for filtering common mode interference on the HDMI differential line.
Optionally, the hot plug pull-down circuit comprises a first resistor and a first capacitor;
the first resistor and the first capacitor are connected in parallel, the first end is connected with the hot plug signal pin of the HDMI male head and the hot plug signal pin of the HDMI port, and the second end connected with the first resistor and the first capacitor in parallel is grounded;
The first resistor is used for keeping a low-level stable state when no signal is input to the hot plug signal interface of the HDMI port, and the first capacitor is used for filtering high-frequency clutter.
Optionally, the consumer electronic control pull-up circuit further comprises a second resistor and a second diode;
The first end of the second resistor and the second diode which are connected in series is connected with the connection end of the CEC control signal pin of the HDMI male head and the CEC control signal pin of the HDMI port;
The second end of the second resistor and the second diode which are connected in series is connected with a power input pin of the HDMI port;
The second resistor is used for keeping a high-level stable state, and the second diode is used for preventing current from flowing backwards.
Optionally, the display data channel impedance matching circuit further comprises a third resistor and a fourth resistor;
the third resistor is connected between the serial clock pin of the HDMI male head and the serial clock pin of the HDMI port;
the fourth resistor is connected between the serial data pin of the HDMI male head and the serial data pin of the HDMI port;
The third resistor and the fourth resistor are used for impedance matching of the signal line and absorb reflected signals.
Optionally, the HDMI protection plate circuit further comprises a first TVS filtering module and a second TVS filtering module;
The first TVS filtering module is connected with the HDMI male pin and is used for preventing the HDMI male pin from being damaged and preventing static electricity;
the second TVS filtering module is connected with the HDMI port and is used for preventing the HDMI port pins from being damaged and preventing static electricity.
In addition, in order to achieve the above object, the present invention also provides an HDMI protection board including the HDMI protection board circuit as described above.
In addition, to achieve the above object, the present invention also provides an apparatus including the HDMI guard circuit as described above.
The HDMI protection plate circuit is connected between an HDMI male head and an HDMI port, and comprises a power supply protection circuit, a plurality of common mode inductance modules, a hot plug pull-down circuit, a display data channel impedance matching circuit and a consumer electronic control pull-up circuit, wherein the power supply protection circuit, the common mode inductance modules, the hot plug pull-down circuit, the display data channel impedance matching circuit and the consumer electronic control pull-up circuit are respectively connected between the HDMI male head and the HDMI port, the power supply protection circuit is used for eliminating fixed frequency interference on a power line and preventing HDMI port current from flowing backwards, the common mode inductance modules are used for filtering common mode interference on an HDMI differential line, the hot plug pull-down circuit is used for keeping a low-level stable state and filtering high-frequency clutter, the consumer electronic control pull-up circuit is used for keeping a high-level stable state, and the display data channel impedance matching circuit is used for impedance matching of a signal line and absorbing reflected signals.
Compared with the traditional HDMI protection mode of protecting ESD through a TVS tube, the protection circuit is connected between an HDMI male head and an HDMI port through a power supply protection circuit, a common mode inductance module, a hot plug pull down circuit, a display data channel impedance matching circuit and a consumer electronics control pull up circuit, so that common mode interference and fixed frequency interference generated during data line transmission in an HDMI interface are filtered, clutter and current reverse irrigation at a power supply input end are prevented, and meanwhile, the problems that CEC (Consumer Electronics Control ), DDC (DISPLAY DATA CHANNEL, display data channels) and a hot plug interface are unstable in state and are easy to trigger by mistake during signal transmission are prevented, and therefore the protection performance of the HDMI interface is greatly improved.
Drawings
FIG. 1 is a schematic diagram of an HDMI guard circuit of the present invention;
FIG. 2 is a schematic diagram of a power protection circuit of the HDMI protection circuit of the present invention;
FIG. 3 is a schematic diagram of a common mode inductance module of the HDMI guard circuit of the present invention;
FIG. 4 is a schematic diagram of a hot plug pull-down circuit of the HDMI protection circuit of the present invention;
FIG. 5 is a schematic diagram of a consumer electronics control pull-up circuit of the HDMI guard circuit of the present invention;
FIG. 6 is a schematic diagram of a display data channel impedance matching circuit of the HDMI guard circuit of the present invention;
Fig. 7 is a schematic diagram of a first TVS filtering module of the HDMI protection circuit of the present invention;
Fig. 8 is a schematic diagram of a second TVS filtering module of the HDMI protection circuit of the present invention;
Fig. 9 is a schematic diagram of an actual application scenario of the HDMI guard circuit of the present invention.
Reference numerals illustrate:
the achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.
Detailed Description
It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Referring to fig. 1, fig. 1 is a schematic diagram of an HDMI guard circuit layout according to an embodiment of the present invention.
The HDMI protection plate circuit is connected between an HDMI male head and an HDMI port, and comprises a power supply protection circuit 10, a plurality of common mode inductance modules 20, a hot plug pull-down circuit 40, a display data channel impedance matching circuit 30 and a consumer electronic control pull-up circuit 50;
the first ends of the power protection circuit 10, the common mode inductance module 20, the hot plug pull-down circuit 40, the display data channel impedance matching circuit 30 and the consumer electronic control pull-up circuit 50 are connected with the HDMI male head;
The second ends of the power protection circuit 10, the common mode inductance module 20, the hot plug pull-down circuit 40, the display data channel impedance matching circuit 30 and the consumer electronic control pull-up circuit 50 are connected with the HDMI port;
the power protection circuit 10 is used for eliminating the interference of fixed frequency on a power line and preventing the reverse current of an HDMI port;
the common mode inductance module 20 is used for filtering common mode interference on the HDMI differential line;
the hot plug low circuit 40 is used for keeping a low-level stable state and filtering high-frequency clutter;
the consumer electronics control pull-up circuit 50 is used to maintain a steady state of high level;
the display data channel impedance matching circuit 30 is used for impedance matching of signal lines to absorb reflected signals.
In this embodiment, as shown in the schematic diagram of the HDMI protection circuit shown in fig. 1, the HDMI protection circuit is connected between the HDMI male head and the HDMI port, and is disposed at the HDMI port side, and the power protection circuit solves the interference problem of the noise wave of the power input port of the HDMI port, and prevents the reverse current filling problem of the HDMI port, and the common mode inductance module solves the common mode interference that easily occurs during data transmission on the HDMI differential line, and the hot plug pull-down circuit is used for maintaining the stable state of the low level and filtering the high frequency noise wave when the signal line is not input.
It should be noted that, the consumer electronic control is CEC, the CEC bus is an Open-Drain (Open-Drain) output similar to IIC (Inter-INTEGRATED CIRCUIT, integrated circuit bus), and cannot output a high level, so that the pull-up resistor needs to be externally applied to pull up, and the consumer electronic control pulls up circuit 50 to 3.3V to prevent an unknown level state from occurring.
It should be noted that, the display data channel is DDC (Display Data Channel), the display data channel impedance matching circuit 30 is used for impedance matching of the signal line and absorbs the reflected signal, when the frequency of the electric signal is relatively high or dv/dt is relatively large, reflection is generated at a place passing through different impedances, for example, when the electric signal passes through pcb from the transmitting end to the receiving end, the reflected signal is overlapped with the signal of the transmitting end, so that the transmission is repeatedly performed at the receiving end, and the display data channel impedance matching circuit 30 solves the problem of absorbing the reflected signal and is used as impedance matching of the signal line.
Optionally, the power protection circuit 10 is connected between a power input pin of the HDMI male and a power input pin of the HDMI port;
the common mode inductance modules 20 are respectively connected between the data differential signal pins of the HDMI male heads and the data differential signal pins of the HDMI ports;
One common mode inductance module 20 is connected between the clock differential signal pin of the HDMI male head and the clock differential signal pin of the HDMI port;
the hot plug low circuit 40 is connected between a hot plug signal pin of the HDMI male head and a hot plug signal pin of the HDMI port;
A first end of the consumer electronic control pull-up circuit 50 is connected with a CEC control signal pin of the HDMI male, and a second end of the consumer electronic control pull-up circuit 50 is connected with a power input pin and a CEC control signal pin of the HDMI port, respectively;
the display data channel impedance matching circuit 30 is connected between the serial pin of the HDMI male head and the serial pin of the HDMI port.
In this embodiment, the pins of the HDMI male and HDMI ports each include a power input pin hdmi_5v, a plurality of data differential signal pins, a clock differential signal pin, a serial clock pin, a serial data pin, a CEC control signal pin, and a hot plug signal pin.
In this embodiment, the power protection circuit is connected between the power input pin 5v_in of the HDMI male head and the power input pin hdmi_5v of the HDMI port, and solves the interference problem of the noise wave of the power input port of the HDMI port and the problem of current reverse-filling of the HDMI port.
In this embodiment, the differential signal pins of the HDMI include a data differential signal pin and a clock differential signal pin, three common-mode inductance modules are respectively connected between the three data differential signal pins of the HDMI male head and the HDMI port, a first common-mode inductance module is connected between a first data differential signal pin of the HDMI male head and a first data differential signal pin of the HDMI port, a second common-mode inductance module is connected between a second data differential signal pin of the HDMI male head and a second data differential signal pin of the HDMI port, a third common-mode inductance module is connected between a third data differential signal pin of the HDMI male head and a third data differential signal pin of the HDMI port, and one common-mode inductance module is connected between the clock differential signal pin of the HDMI male head and the clock differential signal pin of the HDMI port.
In this embodiment, the hot plug low circuit is connected in parallel between the hot plug signal pin hdmi_ HOTPLUG _c of the HDMI male head and the hot plug signal pin hdmi_ HOTPLUG of the HDMI port, so that the signal line maintains a stable state of low level and filters out high frequency noise when no input is made.
In this embodiment, a first end of the consumer electronic control pull-up circuit 50 is connected to the CEC control signal pin hdmi_cec_c of the HDMI male, and a second end of the consumer electronic control pull-up circuit 50 is connected to the power input pin and the CEC control signal of the HDMI port, respectively, so that pulling the voltage pull-up circuit to 3.3V prevents an unknown level state from occurring.
In the present embodiment, the display data channel impedance matching circuit 30 is connected between the serial pin of the HDMI male head including the serial clock pin hdmi_scl_c and the serial data pin hdmi_sda_c and the serial pin of the HDMI port including the serial clock pin hdmi_scl and the serial data pin hdmi_sda, so that the reflected signal is absorbed by the impedance matching of the signal lines.
Optionally, the power protection circuit 10 includes a first diode D1 and a magnetic bead P;
The first diode D1 and the magnetic bead P are connected in parallel between a power input pin 5V_IN of the HDMI male head and a power input pin HDMI_5V of the HDMI port, the magnetic bead P is used for eliminating interference of fixed frequency on a power line, and the first diode D1 is used for preventing current of the HDMI port from flowing backwards.
In this embodiment, the magnetic bead P can effectively filter out the interference of the fixed frequency on the power line, and the first diode D1 is a schottky diode for preventing the reverse current flowing in the HDMI port and damaging the power device.
As an example, as shown in the power protection circuit schematic diagram of the HDMI protection circuit in fig. 2, the power protection circuit may further include a fifth resistor R5 and a sixth resistor R6, where a first end of the fifth resistor R5 and the sixth resistor R6 connected in parallel is connected to the power input pin hdmi_5v of the HDMI port, a second end of the fifth resistor R5 is connected to the serial clock pin hdmi_scl of the HDMI port, and a second end of the sixth resistor R6 is connected to the serial data pin hdmi_sda of the HDMI port, and thus, the function of pulling up the IIC (Inter-INTEGRATED CIRCUIT, integrated circuit bus) signal line of the DDC signal is achieved because the IIC signal is output as Open-Drain (Open-Drain).
Optionally, the common mode inductance module 20 includes a common mode inductance L;
the common mode inductor L is connected between the differential signal pin of the HDMI male head and the differential signal pin of the HDMI port and is used for filtering common mode interference on the HDMI differential line.
It should be noted that, the differential signal pins of the HDMI include a data differential signal pin and a clock differential signal pin, the data differential pin of the HDMI male includes a first data differential pin, a second data differential pin and a third data differential pin, the first data differential pin includes hdmi_tx0p_c and hdmi_tx0n_c, the second data differential pin includes hdmi_tx1p_c and hdmi_tx1n_c, the third data differential pin includes hdmi_tx2p_c and hdmi_tx2n_c, the clock differential pin of the HDMI male includes hdmi_ TXCLKP _c and hdmi_ TXCLKP _c, and the common mode inductor L1 is formed by two coils, and magnetic fluxes in the magnetic loop overlap each other when the common mode current flows through the common mode inductor, so that the common mode inductor has a substantial inductance and has an effect of suppressing the common mode current.
As an example, as shown in the schematic diagram of the common-mode inductance module of the HDMI protection circuit in fig. 3, taking the first data differential pin as an example, the 1 st pin of the common-mode inductance L is connected to the first data differential pin hdmi_tx0n_c of the HDMI male, the 4 th pin of the common-mode inductance is connected to the first data differential pin hdmi_tx0p_c of the HDMI male, the 2 nd pin of the common-mode inductance is connected to the first data differential pin hdmi_tx0N of the HDMI port, the 4 th pin of the common-mode inductance is connected to the hdmi_tx0P of the first data differential pin of the HDMI male, and the second data differential pin, the third data differential pin, the clock differential signal pin and the common-mode inductance are the same as above.
It should be noted that the common-mode inductance module may further include a seventh resistor R7 and an eighth resistor R8, where the first end of the seventh resistor R7 is connected to the 4 th pin of the common-mode inductance L, the second end of the seventh resistor R7 is connected to the 3 rd pin of the common-mode inductance L, the first end of the eighth resistor R8 is connected to the 1 st pin of the common-mode inductance L, the second end of the eighth resistor R8 is connected to the 2 nd pin of the common-mode inductance L, it should be understood that the seventh resistor R7 and the eighth resistor R8 are applied to the connection of the first data differential pin, the second data differential pin, the third data differential pin, the clock differential signal pin and the common-mode inductance L, and it should be understood that the seventh resistor R7 and the eighth resistor R8 are designed to be compatible with one common-mode inductance L, and the cost of the common-mode inductance L is reduced by the seventh resistor R7 and the eighth resistor R8 when actually applied.
Optionally, the hot plug pull-down circuit 40 includes a first resistor R1 and a first capacitor C1;
The first resistor R1 and the first capacitor C1 are connected in parallel, the first end is connected with the connection end of the hot plug signal pin HDMI_ HUTPLUG _C of the HDMI male head and the hot plug signal pin HDMI_ HUTPLUG of the HDMI port, and the second end of the first resistor R1 and the first capacitor C1 which are connected in parallel is grounded;
The first resistor R1 is used for maintaining a low-level stable state when the hot plug signal interface hdmi_ HUTPLUG of the HDMI port has no signal input, and the first capacitor C1 is used for filtering high-frequency clutter.
It should be noted that, when the hot plug signal is high, the HDMI is switched to the on state by pulling high internally when it is on, so the voltage of the signal line needs to be pulled down by the first resistor R1, so that the signal line is in a low-level stable state when no input is performed, and the first capacitor C1 plays a role in filtering high-frequency noise.
As illustrated in the schematic hot plug pull-down circuit of the HDMI protection circuit shown in fig. 4, the hot plug pull-down circuit may further include a ninth resistor R9, where the ninth resistor R9 is connected between the hot plug signal pin hdmi_ HUTPLUG _c of the HDMI male connector and the hot plug signal pin hdmi_ HUTPLUG of the HDMI port, and the ninth resistor R9 plays a role of current limiting, so as to prevent burning out of the terminal or the chip due to excessive current.
Optionally, the consumer electronic control pull-up circuit 50 further comprises a second resistor R2, a second diode D2;
The first end of the second resistor R2 and the second diode D2 which are connected in series is connected with the connection end of the CEC control signal pin HDMI_CEC of the HDMI male head and the CEC control signal pin HDMI_CEC of the HDMI port;
the second end of the second resistor R2 and the second diode D2 which are connected in series is connected with a power input pin HDMI_5V of the HDMI port;
The second resistor R2 is used for maintaining a high-level stable state, and the second diode D2 is used for preventing current reverse-filling.
In this embodiment, as shown in the schematic diagram of the consumer electronic control pull-up circuit of the HDMI protection circuit in fig. 5, the consumer electronic control pull-up circuit 50 may further include a tenth resistor R10, an eleventh resistor R11, and a twelfth resistor R12, where a first end of the tenth resistor R10 and the eleventh resistor R11 connected in parallel is connected to the second end of the second diode D2, the second end of the tenth resistor R10 is grounded, the eleventh resistor R11 is connected to the power input pin hdmi_5v of the HDMI port, the tenth resistor R10 and the eleventh resistor R11 play a role of reducing the voltage of 5V to 3.3V, and are pulled up by the second resistor R2, to maintain a stable state of high level, and the twelfth resistor R12 is connected between the CEC control signal pin_cec of the male head and the CEC control signal pin hdmi_cec of the HDMI port, to play a role of limiting current, and prevent the HDMI terminal or HDMI chip from being burned out due to excessive current.
Optionally, the display data channel impedance matching circuit 30 further includes a third resistor R3 and a fourth resistor R4;
the third resistor R3 is connected between the serial clock pin hdmi_scl_c of the HDMI male head and the serial clock pin hdmi_scl of the HDMI port;
The fourth resistor R4 is connected between the serial data pin hdmi_sda_c of the HDMI male and the serial data pin hdmi_sda of the HDMI port;
The third resistor R3 and the fourth resistor R4 are used for impedance matching of the signal line and absorb the reflected signal.
In this embodiment, as shown in the schematic diagram of the impedance matching circuit of the display data channel of the HDMI protection board circuit in fig. 6, the DDC signal line includes a serial clock signal line SCL and a serial data signal line SDA, the third resistor R3 and the fourth resistor R4 are used for impedance matching of the signal line, and absorb the reflected signal, when the frequency of the electrical signal is relatively high, or dv/dt is relatively large, reflection occurs at a place passing through different impedances, for example, when the electrical signal passes through pcb from the transmitting end to the receiving end, the reflected signal is superimposed with the signal of the transmitting end, so that the transmission is repeatedly performed at the receiving end, and the absorption reflected signal is solved by the third resistor R3 and the fourth resistor R4, and is used as impedance matching of the signal line.
The HDMI protection plate circuit is connected between an HDMI male head and an HDMI port, and comprises a power protection circuit, a plurality of common mode inductance modules, a hot plug pull-down circuit, a display data channel impedance matching circuit 30 and a consumer electronic control pull-up circuit 50, wherein the power protection circuit, the common mode inductance modules, the hot plug pull-down circuit, the display data channel impedance matching circuit 30 and the consumer electronic control pull-up circuit 50 are respectively connected between the HDMI male head and the HDMI port, the power protection circuit is used for eliminating fixed frequency interference on a power line and preventing HDMI port current from flowing backwards, the common mode inductance modules are used for filtering common mode interference on an HDMI differential line, the hot plug pull-down circuit is used for keeping a low-level stable state and filtering high-frequency clutters, the consumer electronic control pull-up circuit is used for keeping a high-level stable state, the display data channel impedance matching circuit is used for impedance matching of a signal line, and absorbing reflection signals.
According to the invention, the power protection circuit, the common mode inductance module, the hot plug pull-down circuit, the display data channel impedance matching circuit and the consumer electronic control pull-up circuit are respectively connected between the HDMI male head and the HDMI port, so that common mode interference and fixed frequency interference generated during data line transmission in the HDMI interface are filtered, the problems of clutter and current reverse filling of a power input end are prevented, and meanwhile, the problems that CEC (Consumer Electronics Control, consumer electronic control), DDC (DISPLAY DATA CHANNEL ) and the hot plug interface are unstable in state and are easy to trigger by mistake during no-signal transmission are prevented, and the protection performance of the HDMI interface is greatly improved.
Alternatively, based on the first embodiment of the HDMI guard circuit of the present invention as described above, a second embodiment of the HDMI guard circuit of the present invention is proposed.
In some possible embodiments, the HDMI guard plate circuit further includes a first TVS filtering module 60 and a second TVS filtering module 70;
The first TVS filtering module 60 is connected to the HDMI male connector, and the first TVS tube 60 is configured to prevent the HDMI male connector pin from being damaged and from being electrostatically charged;
the second TVS filtering module 70 is connected to the HDMI port, and the second TVS filtering module 70 is configured to prevent the HDMI port pin from being damaged and from being electrostatically charged.
In this embodiment, the first TVS filter module 60 is connected between the HDMI male terminal and the common-mode inductor module 20, and the second TVS filter module 70 is connected between the common-mode inductor module 20 and the HDMI port, so that the HDMI port is clamped at a fixed value when the voltage is high, the high HDMI port voltage is avoided, and the ESD (Electro-STATIC DISCHARGE, electrostatic discharge) is prevented.
As an example, as shown in the first TVS filtering module schematic diagram of the HDMI protection circuit in fig. 7, the first TVS filtering module 60 includes a first TVS chip U1 and a second TVS chip U2, the 1 st and 10 th pins of the first TVS chip U1 are respectively connected to the third data differential signal hdmi_tx2p_c of the HDMI male head, the 2 nd and 9 th pins of the first TVS chip U1 are respectively connected to the third data differential signal hdmi_tx2n_c of the HDMI male head, the 4 th and 7 th pins of the first TVS chip U1 are respectively connected to the second data differential signal hdmi_tx1p_c of the HDMI male head, the 5 th and 6 th pins of the first TVS chip U1 are respectively connected to the third data differential signal hdmi_tx1n_c of the HDMI male head, the 1 st pin of the second TVS chip U2 is respectively connected to the first data differential signal hdmi_tx0p_c of the HDMI male head, the second pin of the HDMI chip U2 is respectively connected to the second data differential signal hdmi_tx2n_c of the HDMI male head, the 4 th pin of the second TVS chip U2 is respectively connected to the second data differential signal hdmi_tx2n_c of the HDMI male head, and the 5 th pin of the second TVS chip U2 is respectively connected to the second data differential signal hdmi_tx2p_c of the second TVS chip U2.
As an example, as shown in the schematic diagram of the second TVS filtering module of the HDMI protection circuit shown in fig. 8, the second TVS filtering module 70 includes a third TVS chip U3, a fourth TVS chip U4 and a fifth TVS chip U5, the 1 st and 10 th pins of the third TVS chip U3 are respectively connected with the third data differential signal hdmi_tx2P of the HDMI port, the 2 nd and 9 th pins of the first TVS chip U1 are respectively connected with the third data differential signal hdmi_tx2N of the HDMI port, the 4 th and 7 th pins of the first TVS chip U1 are respectively connected with the second data differential signal hdmi_tx1p_c of the HDMI port, the 5 th and 6 th pins of the first TVS chip U1 are respectively connected with the third data differential signal hdmi_tx1n_c of the HDMI port, the 1 st pin of the fourth TVS chip U2 is respectively connected with the 10 th pin of the HDMI port, the 2 nd pin and the 9 th pin of the second TVS chip U2 are respectively connected with the first data differential signal hdmi_tx0n_c of the HDMI port, the 4 th pin and the 7 th pin of the second TVS chip U2 are respectively connected with the clock differential signal hdmi_ TXCLKP _c of the HDMI port, the 5 th pin and the 6 th pin of the second TVS chip U2 are respectively connected with the clock differential signal hdmi_ TXCLKN _c of the HDMI port, the 1 st pin of the fifth TVS chip U5 is connected with the CEC control signal pin hdmi_cec of the HDMI port, the 2 nd pin of the fifth TVS chip U5 is grounded, the 3 rd pin of the fifth TVS chip U5 is connected with the serial clock pin hdmi_scl of the HDMI port, the 4 th pin of the fifth TVS chip U5 is connected with the hot plug signal pin hdmi_ HUTPLUG of the HDMI port, the 5 th pin of the fifth TVS chip U5 is connected with the power input pin hdmi_5v of the HDMI port, and the 6 th pin of the fifth TVS chip U5 is connected with the serial data pin hdmi_sda of the HDMI port.
It should be noted that, referring to fig. 9, fig. 9 is a schematic diagram of an actual application scenario of the HDMI protection board circuit of the present invention, in the actual application scenario, the placement positions of the modules are shown in fig. 9, the first TVS filtering module 60 is placed between the HDMI male head and the common-mode inductance module 20, and the second TVS filtering module 70 is placed between the common-mode inductance module 20 and the HDMI port, so that the first TVS filtering module 60 filters the pair of clock signals and the three pairs of data signals, the second TVS filtering module 70 filters the pair of clock signals, the three pairs of data signals, the DDC signal, the HOTPLUG signal and the CEC signal, and the first TVS chip U1 and the second TVS chip U2 prevent the pin from being damaged by the male head and prevent static electricity, and the third TVS chip U3, the fourth TVS chip U4 and the fifth TVS chip U5 prevent the HDMI port from being damaged by the pin and prevent static electricity.
In this embodiment, the HDMI protection board circuit of the present invention is connected in parallel between the HDMI male head and the common-mode inductance module, and the second TVS filtering module is connected in parallel between the common-mode inductance module and the HDMI port, so as to filter common-mode interference and fixed-frequency interference occurring during data line transmission in the HDMI interface, prevent the problem of clutter and current reverse-filling at the power input end, and simultaneously prevent the problem that CEC (Consumer Electronics Control, consumer electronic control), DDC (DISPLAY DATA CHANNEL ) and hot-plug interface are unstable in state and are prone to false triggering when no signal is transmitted, and prevent pins of the HDMI male head and the HDMI port from being damaged, and prevent ESD problem, thereby greatly improving the protection performance of the HDMI interface.
The embodiment of the invention also provides an HDMI protection plate, which comprises the HDMI protection plate circuit in any embodiment.
In this embodiment, the HDMI protection board of this embodiment has the same technical effects as the HDMI protection board circuit described above thanks to the HDMI protection board circuit described above, and will not be described here again.
The embodiment of the invention also provides a village, which comprises the HDMI protection plate circuit in any one of the embodiments.
In this embodiment, thanks to the HDMI protection board circuit, the device of this embodiment has the same technical effects as the HDMI protection board circuit, and will not be described herein.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or system. Without further limitation, an element defined by the phrase "comprising one does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.
The foregoing embodiment numbers of the present invention are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.
From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art in the form of a software product stored in a storage medium (e.g. ROM/RAM, magnetic disk, optical disk) as described above, comprising instructions for causing a terminal device (which may be a mobile phone, a computer, a server, or a network device, etc.) to perform the method according to the embodiments of the present invention.
The foregoing description is only of the preferred embodiments of the present invention, and is not intended to limit the scope of the invention, but rather is intended to cover any equivalents of the structures or equivalent processes disclosed herein or in the alternative, which may be employed directly or indirectly in other related arts.
Claims (5)
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| CN108039347A (en) * | 2018-01-17 | 2018-05-15 | 上海长园维安微电子有限公司 | A kind of integrated ultra-low capacitance returns greatly the common mode filtering device of TVS suddenly |
| CN109391839A (en) * | 2017-08-10 | 2019-02-26 | 北京正唐科技有限责任公司 | A kind of adaptive H DMI Interface Video transmitting device |
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| US8502073B2 (en) * | 2010-07-13 | 2013-08-06 | John Martin Horan | Low impedance boosted high speed data cable |
| CN203193775U (en) * | 2013-02-05 | 2013-09-11 | 林春生 | Power supply system for HDMI high definition signal distributor |
| CN210222601U (en) * | 2019-06-12 | 2020-03-31 | 中兴威视(大连)科技发展有限公司 | Industrial control mainboard with electromagnetic protection circuit |
| CN215344370U (en) * | 2021-07-14 | 2021-12-28 | 深圳市递百科技术有限公司 | HDMI filtering protection circuit capable of effectively suppressing EMC interference |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109391839A (en) * | 2017-08-10 | 2019-02-26 | 北京正唐科技有限责任公司 | A kind of adaptive H DMI Interface Video transmitting device |
| CN108039347A (en) * | 2018-01-17 | 2018-05-15 | 上海长园维安微电子有限公司 | A kind of integrated ultra-low capacitance returns greatly the common mode filtering device of TVS suddenly |
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