Port expansion circuit and device

Abstract

The application relates to a port expansion circuit and device, and belongs to the technical field of electronic device connection. The port expansion circuit comprises a main power interface module, a first relay module and a slave power interface module, the main power interface module is connected with the first relay module and an external power device, the slave power interface module is connected with the first relay module and an expansion device, and the first relay module performs filtering, shaping and amplification processing on transmitted data signals. The port expansion circuit further comprises a main data interface module, a second relay module and a slave data interface module, which are used for realizing transmission and processing of data signals. The first relay module comprises a biasing submodule and an operational amplification submodule, and the second relay module comprises an isolation transformer, a common-mode inductor and a protocol conversion chip. Through the separation design of power transmission and data transmission, the application realizes effective expansion of the port, improves signal transmission quality and stability, supports multiple interface types, and meets the connection requirements of different devices.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electronic interface expansion, in particular to a port expansion circuit and device. BACKGROUND

[0002] With the rapid development of electronic devices, the types and quantities of interfaces of various electronic devices are increasing, and users' demands for device connection and expansion are also increasing. As an important tool to solve the problem of insufficient interfaces of electronic devices, port expansion devices have been widely used in various scenarios. At present, the common port expansion devices on the market mainly connect to the host device through USB, Type-C and other interfaces, and provide various types of expansion interfaces such as HDMI, VGA, USB, etc. to meet the diversified needs of users.

[0003] However, there are some technical problems in the design of existing port expansion devices. In the traditional port expansion dock design, the signal lines of the first USB-C female port and the first USB-C male port are directly connected. This design directly affects the charging efficiency and data transmission rate of the copper wire on the PCB. Hardware engineers must carefully design the signal wire, and the signal wire length cannot be too long, and the problem of electromagnetic interference must also be considered. This direct connection method is easily disturbed by the external environment, resulting in a decline in signal quality, especially in high-speed data transmission and high-power charging scenarios, the problem is more prominent.

[0004] In addition, the port expansion devices in the prior art often lack effective signal processing mechanisms such as filtering, shaping and amplification when processing data signals of different protocols, resulting in a decline in signal quality in long-distance transmission or complex electromagnetic environments. At the same time, the existing devices also have deficiencies in the cooperative processing of power transmission and data transmission, making it difficult to meet users' demands for efficient and stable expansion functions.

[0005] Therefore, there is an urgent need for a port expansion circuit that can effectively solve the above problems by optimizing power transmission and data transmission paths, improving signal quality and transmission efficiency, and at the same time having good anti-interference ability and protocol compatibility. CONTENT OF THE INVENTION

[0006] The main purpose of the present application is to provide a port expansion circuit and device, which aims to solve the problem that in the existing port expansion dock design, the signal lines of the female port and the male port are directly connected, which directly affects the charging efficiency and data transmission rate, and also needs to consider the problem of electromagnetic interference.

[0007] To achieve the above objectives, this application proposes a port expansion circuit, comprising: a main power interface module, a first relay module, and a slave power interface module; the main power interface module is connected to the first relay module and an external power device; the slave power interface module is connected to the first relay module and the device to be expanded; the power interface module is used to realize power transmission and data transmission between the external device and the first relay module; the slave power interface module is used to realize power transmission and data transmission between the device to be expanded and the first relay module; the first relay module is used to filter, shape, and amplify the data signals transmitted by the main power interface module and the slave power interface module.

[0008] In one embodiment, the port expansion circuit further includes: a main data interface module, a second relay module, and a slave data interface module; the main data interface module is connected to the second relay module and an external signal device; the slave data interface module is connected to the second relay module and the device to be expanded; the main data interface module is used to receive data signals sent by an external data source and transmit the data signals to the second relay module; the slave data interface module is used to transmit the data signals processed by the second relay module to the device to be expanded; the slave data interface module is also used to receive feedback data signals from the device to be expanded and transmit them to the second relay module; the main data interface module is also used to receive feedback data signals sent by the second relay module and transmit them to an external signal device; the second relay module is used to perform protocol conversion, data buffering, and signal enhancement processing on the data signals transmitted by the main data interface module and the slave data interface module.

[0009] In one embodiment, the main data interface module includes multiple main data interfaces, each of which is connected to the second relay module and multiple external signal devices.

[0010] In one embodiment, the first relay module includes: a bias submodule and an operational amplifier submodule; the operational amplifier submodule is connected to the bias submodule, the main power interface module, and the slave power interface module, respectively; the bias submodule is used to provide a bias voltage to the operational amplifier submodule; the operational amplifier submodule is used to amplify the data signal input from the main power interface module based on the bias voltage and transmit it to the slave power interface module.

[0011] In one embodiment, the operational amplifier submodule includes: a first operational amplifier; the non-inverting input terminal of the first operational amplifier is connected to the main power interface module; the inverting input terminal and the output terminal of the first operational amplifier are connected to the slave power interface module; and the controlled terminal of the first operational amplifier is connected to the bias submodule.

[0012] In one embodiment, the bias submodule includes a voltage divider circuit or a voltage regulator chip, which obtains the bias voltage from the power transmitted through the main power interface module.

[0013] In one embodiment, the second relay module further includes an isolation transformer, a common-mode inductor, and a protocol conversion chip; the isolation transformer is connected between the main data interface module and the slave data interface module to suppress common-mode interference; the common-mode inductor is connected in series in the data signal transmission path between the main data interface module and the slave data interface module to filter out high-frequency noise; the protocol conversion chip is connected between the main data interface module and the slave data interface module to support protocol adaptation from HDMI to VGA or from USB to RS485.

[0014] In one embodiment, the main power interface module includes either a USB interface or a C interface.

[0015] In one embodiment, the main data interface module includes one of an HDMI interface, a VGA interface, or a DP interface.

[0016] In addition, to achieve the above objectives, this application also proposes a port expansion device that uses the port expansion circuit described above.

[0017] One or more technical solutions proposed in this application have at least the following technical effects:

[0018] By adding an interconnect and relay module—the first relay module—between the main power interface module and the slave power interface module, the traditional direct connection design is replaced. This relay module can filter, shape, and amplify the transmitted data signals, effectively enhancing signal capability and improving the signal transmission quality between ports. Simultaneously, the operational amplifier submodule within the first relay module can amplify the signal, further improving the reliability of data transmission.

[0019] Furthermore, when a second relay module is configured, its included isolation transformer and common-mode inductor effectively reduce electromagnetic interference, while the protocol conversion chip provides compatibility with multiple interface protocols, thereby comprehensively improving the charging efficiency and data transmission rate of the port expansion device. Compared with existing technologies, this application solves the problem of limited signal quality under direct connection by adding a signal relay processing stage, enabling the port expansion device to have higher performance and a wider range of application scenarios. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a structural block diagram of the first embodiment of the port expansion circuit of this application;

[0023] Figure 2 This is a structural block diagram of the second embodiment of the port expansion circuit of this application;

[0024] Figure 3 This is a structural block diagram of the third embodiment of the port expansion circuit of this application;

[0025] Figure 4 This is a schematic diagram illustrating a specific implementation of the first relay module in the third embodiment of this application.

[0026] Explanation of icon numbers:

[0027] 10 Master power interface module 12 Slave power interface module 11 First relay module 20 Master data interface module 111 Biasing sub-module 21 Second relay module 112 Operational amplification sub-module 22 Slave data interface module

[0028] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0029] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0030] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0031] Existing port expansion device designs have several technical issues. In traditional port expansion dock designs, the signal lines of the first USB-C female port and the first USB-C male port are typically directly connected. This design means that the quality of the copper traces on the PCB directly affects charging efficiency and data transfer rates. Hardware engineers must carefully design the signal traces, ensuring their length is not too long, and also consider electromagnetic interference. This direct connection method is susceptible to interference from the external environment, leading to signal quality degradation, especially in high-speed data transfer and high-power charging scenarios.

[0032] Based on this, embodiments of this application provide a port expansion circuit, referring to... Figure 1 , Figure 1 This is a structural block diagram of the first embodiment of the port expansion circuit of this application.

[0033] In this embodiment, the port expansion circuit includes a main power interface module 10, a first relay module 11, and a secondary power interface module 12. The main power interface module 10 is connected to the first relay module 11 and an external power device. The secondary power interface module 12 is connected to the first relay module 11 and the device to be expanded.

[0034] It should be noted that the main power interface module 10 is used to realize power transmission and data transmission between external power equipment and the first relay module 11.

[0035] It should be noted that the main power interface module 10 can use a USB interface that conforms to the USB 3.0 standard, supporting 5V / 3A power delivery and a data transfer rate of 5Gbps. The main power interface module 10 connects to external power devices via a standard USB cable. These external power devices can be USB-powered devices such as power banks. The main power interface module 10 may integrate an overcurrent protection circuit; when the detected current exceeds 3.5A, it will automatically disconnect the circuit to protect the circuit and device safety.

[0036] It should be noted that the power interface module 12 is used to realize power transmission and data transmission between the device to be expanded and the first relay module 11.

[0037] It should be noted that the secondary power interface module 12 uses the same USB interface as the main power interface module, supporting 5V / 3A power delivery and 5Gbps data transfer rate. The secondary power interface module connects to the device to be expanded via a standard USB cable. The device to be expanded is an electronic device whose functionality, performance, or connectivity can be improved through hardware or software means; laptops are a typical example. The secondary power interface module 12 integrates a voltage stabilization circuit, which can stabilize the input 5V voltage within ±0.1V, ensuring a stable power supply to the device to be expanded. It should be connected to the charging interface of the device to be expanded.

[0038] It should be noted that the first relay module 11 is used to filter, shape and amplify the data signals transmitted from the main power interface module 10 and the power interface module 12.

[0039] It should be noted that the first relay module 11 employs a high-performance signal processing circuit, which may include multi-stage filtering circuits, signal shaping circuits, and amplification circuits. The filtering circuit uses an LC filter structure, composed of inductors and capacitors, with a cutoff frequency set to 2MHz, effectively filtering out high-frequency noise interference. The signal shaping circuit uses a Schmitt trigger structure, which can convert irregular waveforms into standard square wave signals, improving the signal's anti-interference capability. The amplification circuit uses operational amplifiers with an adjustable gain range of 1-10 times, automatically adjusting the gain according to the actual transmission distance to ensure signal quality.

[0040] In practical applications, when external power equipment is connected to the port expansion circuit through the main power interface module 10, the power and data signals first enter the first relay module 11. The first relay module 11 performs voltage regulation to ensure that the output voltage is stable within the range of 5V±0.1V; at the same time, it performs filtering, shaping, and amplification processing on the data signals to filter out noise interference, shape the signal waveform, and amplify the signal strength. The processed power and data signals are then transmitted from the power interface module 12 to the device to be expanded, realizing the port expansion function.

[0041] In this embodiment, an interconnection and relay module, namely the first relay module, is added between the main power interface module and the slave power interface module, replacing the traditional direct connection design. This relay module can filter, shape, and amplify the transmitted data signals, effectively enhancing signal capability and improving the signal transmission quality between ports.

[0042] Furthermore, based on the first embodiment of this application, in the second embodiment of this application, the content that is the same as or similar to that in Embodiment 1 above can be referred to the above description, and will not be repeated hereafter. Please refer to Figure 2 , Figure 2 This is a structural block diagram of a second embodiment of the port expansion circuit of this application.

[0043] In this embodiment, the port expansion circuit further includes a main data interface module 20, a second relay module 21, and a slave data interface module 22. The main data interface module 20 is connected to the second relay module 21 and an external signal device. The slave data interface module 22 is connected to the second relay module 21 and the device to be expanded.

[0044] It should be noted that the main data interface module 20 is used to receive data signals sent by external signal devices and transmit the data signals to the second relay module 21. The slave data interface module 22 is used to transmit the data signals processed by the second relay module 21 to the device to be expanded. The slave data interface module 22 is also used to receive feedback data signals from the device to be expanded and transmit them to the second relay module 21. The main data interface module 20 is also used to receive feedback data signals sent by the second relay module 21 and transmit them to external signal devices. The second relay module 21 is used to perform protocol conversion, data buffering, and signal enhancement processing on the data signals transmitted by the main data interface module 20 and the slave data interface module 22.

[0045] It should be noted that the main data interface module 20 can use an HDMI interface, conforming to the HDMI 2.0 standard, and supports 4K@60Hz video transmission and multi-channel audio transmission. The main data interface module 20 connects to external signal devices via a standard HDMI cable. These external signal devices can be laptops, desktop computers, game consoles, or Blu-ray players, or other devices with HDMI output capabilities. The main data interface module 20 integrates ESD protection circuitry, capable of withstanding ±8kV electrostatic discharge, ensuring circuit safety.

[0046] It should be noted that the second relay module 21 employs a high-performance signal processing chip, supporting HDMI signal protocol parsing, data buffering, and signal enhancement functions. The protocol parsing section uses a dedicated HDMI decoding chip, which can resolve the HDMI signal into video data, audio data, and control data. The data buffering section uses a high-speed SRAM chip with a capacity of 4MB, capable of buffering a certain amount of video frame data to reduce transmission latency. The signal enhancement section uses a dedicated signal equalizer chip, which can preload high-frequency signals to compensate for high-frequency losses caused by transmission cables, thereby improving signal quality.

[0047] It should be noted that the secondary data interface module 22 also uses an HDMI interface, conforms to the HDMI 2.0 standard, and supports the same transmission capabilities as the main data interface module 20. The secondary data interface module 22 connects to the device to be expanded via a standard HDMI cable, connecting to the data interface of the device. The secondary data interface module integrates a signal drive circuit, providing sufficient driving capability to support HDMI cable connections up to 15 meters in length.

[0048] In addition, the main data interface module 20 may include multiple main data interfaces, each of which is connected to the second relay module and multiple external signal devices.

[0049] Specifically, the main data interface module 20 includes three HDMI ports, labeled HDMI-IN1, HDMI-IN2, and HDMI-IN3. All three HDMI ports comply with the HDMI 2.0 standard, supporting 4K@60Hz video transmission and multi-channel audio transmission. Each HDMI port can independently connect to an external signal device, such as a monitor. These three HDMI ports are connected to the second repeater module 21 via a 3×1 HDMI switching chip. The HDMI switching chip employs a high-performance multiplexer structure, supporting lossless switching of three HDMI signals with a switching time of less than 100ms. The HDMI switching chip is connected to the control circuit via an I2C bus, allowing input source switching to be controlled via buttons or a remote control.

[0050] In practical applications, users can simultaneously connect multiple external signal devices to different HDMI ports on the port expansion circuit and then select the currently active input source through a switching control. This design greatly increases the practicality and flexibility of the port expansion circuit, eliminating the need for frequent plugging and unplugging of HDMI cables; users can switch between different signal sources with a simple switching operation.

[0051] The specific process is as follows: When an external signal device is connected to the port expansion circuit through the main data interface module 20, the HDMI signal first enters the second relay module 21. The second relay module 21 performs protocol parsing on the HDMI signal, separating and processing video, audio, and control data; then, it buffers the data to reduce transmission latency; finally, it enhances the signal to compensate for transmission loss. The processed HDMI signal is then transmitted from the data interface module 22 to the device to be expanded, enabling the transmission of high-definition video and audio.

[0052] Meanwhile, the device to be expanded can also send feedback signals, such as device information, resolution capability, and HDCP certification data, to external signal devices via the HDMI CEC (Consumer Electronics Control) channel or DDC (Display Data Channel). These feedback signals first enter the second relay module 21 from the data interface module 22, and after processing, are transmitted back to the external signal device through the main data interface module 20, realizing bidirectional communication.

[0053] Furthermore, to aid in understanding the specific implementation of the port expansion circuit obtained by combining this embodiment with the above embodiments, please refer to... Figure 3 , Figure 3 This is a structural block diagram of the third embodiment of the port expansion circuit of this application.

[0054] In this embodiment, the first relay module 11 includes a bias submodule 111 and an operational amplifier submodule 112. The operational amplifier submodule is connected to the bias submodule 111, the main power interface module 10, and the slave power interface module 12, respectively.

[0055] It should be noted that the bias submodule 111 is used to provide a bias voltage for the operational amplifier submodule. The operational amplifier submodule 112 is used to amplify the data signal input from the main power interface module 10 based on the bias voltage and transmit it to the slave power interface module.

[0056] It should be noted that the bias submodule employs a voltage divider circuit structure, consisting of two precision resistors with resistances of 10kΩ and 20kΩ respectively, forming a 1:2 voltage divider ratio. It obtains approximately 1.67V of bias voltage from the 5V power supplied by the main power interface module. The stability of this bias voltage is crucial for the normal operation of the operational amplifier submodule. Therefore, a 100μF electrolytic capacitor and a 0.1μF ceramic capacitor are connected in parallel at the end of the voltage divider circuit to filter out power supply ripple and improve the stability of the bias voltage.

[0057] It should be noted that the operational amplifier submodule 112 includes a first operational amplifier. The non-inverting input of the first operational amplifier is connected to the main power interface module. The inverting input and output of the first operational amplifier are connected to the slave power interface module 12. The controlled terminal of the first operational amplifier is connected to the bias submodule 111.

[0058] It should be noted that the first operational amplifier can be an LM358 dual operational amplifier chip, with an operating voltage range of 3-32V, a unity-gain bandwidth of 1MHz, and an output current capability of 20mA. The non-inverting input of the first operational amplifier is connected to the data line of the main power interface module through a 10kΩ current-limiting resistor to receive data signals. The inverting input of the first operational amplifier is connected to the output through a 100kΩ feedback resistor, forming a non-inverting amplifier circuit structure with a gain of 11. The output of the first operational amplifier is connected to the data line of the power interface module 12 through a 100Ω resistor to output the amplified data signal. The controlled terminal (i.e., the power pin) of the first operational amplifier is connected to the bias submodule to obtain a stable operating voltage.

[0059] Specifically, please refer to Figure 4 , Figure 4 This is a schematic diagram illustrating a specific implementation of the first relay module in the third embodiment of this application.

[0060] It should be noted that INA+ / INB+ are the main signal inputs, such as sensor or audio signals, which go directly into the op-amp for amplification. C0 and C1 are auxiliary inputs, used solely for bias control and do not participate in the main signal amplification.

[0061] Understandably, C0 and C1 are directly connected to the Bias Control module, indicating that they are the input signal sources for this module. C0 and C1 can provide two types of signals: a DC bias voltage, setting the quiescent operating point for the op-amps (A / B) (e.g., boosting the signal to medium voltage when powered by a single supply); or a dynamic control signal, adjusting bias parameters (e.g., gain, bandwidth) via an external voltage or logic level. If C0 and C1 are fixed voltage inputs, they ensure the op-amp operates in the linear region; if they are adjustable signals, they may be used for automatic calibration or dynamic optimization (e.g., temperature compensation). The input signals of C0 and C1 are processed within the Bias Control module (e.g., filtering, voltage following, voltage division) to generate a stable bias voltage. The processed signal is then passed to the controlled terminals of operational amplifiers A and B in the diagram, ensuring that the input signals INA+ and INB+ are at appropriate DC levels before amplification.

[0062] Understandably, in differential input scenarios INA+ / INA- and INB+ / INB-, the common-mode voltage is adjusted via C0 / C1 to enable the op-amp to efficiently suppress common-mode noise. The DC level of the main signal INA+ / INB+ is adjusted to match the op-amp's operating range via the bias control of C0 / C1, ensuring that the amplified signal output OUTA / OUTB remains undistorted.

[0063] In actual operation, when the main power interface module 10 receives a data signal from an external power device, the signal first enters the non-inverting input of the first operational amplifier. The first operational amplifier operates under a stable bias voltage provided by the bias submodule, amplifying the input signal while maintaining its phase. The amplified signal is then transmitted from the output of the first operational amplifier to the power interface module 12, and finally to the device to be expanded. This amplification effectively compensates for signal attenuation during transmission, ensuring the integrity and reliability of the data signal.

[0064] In addition, the second relay module 21 also includes an isolation transformer, a common-mode inductor, and a protocol conversion chip. The isolation transformer is connected between the main data interface module 20 and the slave data interface module 22 to suppress common-mode interference. The common-mode inductor is connected in series in the data signal transmission path between the main data interface module 20 and the slave data interface module 22 to filter out high-frequency noise. The protocol conversion chip is connected between the main data interface module 20 and the slave data interface module 22 to support protocol adaptation from HDMI to VGA or from USB to RS485.

[0065] Understandably, the isolation transformer employs a high-frequency magnetic ring structure, operating in the 1MHz-1GHz frequency range, with an insertion loss of less than 0.5dB and an isolation voltage greater than 1500V. The primary side of the isolation transformer is connected to the differential data lines of the main data interface module, and the secondary side is connected to the differential data lines of the slave data interface module. Through the principle of electromagnetic induction, the isolation transformer can transmit high-speed differential signals while blocking common-mode interference and ground loop noise, thus improving the signal's anti-interference capability.

[0066] Understandably, the common-mode inductor uses a dual-winding structure with an inductance value of 100μH, a rated current of 1A, and a DC resistance of less than 0.5Ω. Connected in series on the differential data line between the main data interface module and the slave data interface module, the common-mode inductor has almost no impact on the differential signal, but it has a high impedance to common-mode noise, effectively filtering out high-frequency common-mode noise and improving signal quality.

[0067] Understandably, the protocol conversion chip uses a multi-protocol-supporting application-specific integrated circuit (ASIC), internally integrating functional modules such as an HDMI decoder, VGA encoder, USB controller, and RS485 transceiver. Through configuration registers, the protocol conversion chip can achieve conversion between different protocols. For example, HDMI to VGA conversion can convert digital HDMI signals to analog VGA signals, supporting older display devices; USB to RS485 conversion can convert data from the USB interface to the commonly used RS485 bus signals, supporting industrial control applications.

[0068] In practical applications, when connecting devices with different interface types, the protocol conversion chip automatically detects the input signal type and output device type, and then configures the corresponding conversion mode. For example, when an HDMI input signal and a VGA output device are detected, the protocol conversion chip will activate the HDMI to VGA conversion mode, converting the digital video signal into an analog video signal; when a USB input signal and an RS485 output device are detected, the protocol conversion chip will activate the USB to RS485 conversion mode, enabling communication between the computer and industrial equipment.

[0069] The main power interface module includes either a USB interface or a Type-C interface. In this embodiment, the main power interface module uses a USB Type-C interface, compliant with the USB Power Delivery 3.0 standard, supporting a maximum power delivery capacity of 20V / 5A and a data transfer rate of 10Gbps. The USB Type-C interface features a symmetrical design, allowing insertion from either side for greater convenience. An integrated electronic tag chip within the interface enables power negotiation with external power devices, adjusting the output voltage and current according to actual needs to improve energy efficiency.

[0070] The main data interface module includes one of an HDMI interface, a VGA interface, or a DP interface. In this embodiment, the main data interface module uses a DisplayPort interface, conforming to the DisplayPort 1.4 standard, supporting 8K@60Hz video transmission and multi-channel audio transmission. The DisplayPort interface uses a 20-pin design, supports a maximum bandwidth of 32.4Gbps, and can transmit ultra-high-definition video signals. The interface integrates an adaptive equalization circuit, which can automatically adjust the signal gain according to the cable length to ensure signal quality.

[0071] In this embodiment, the isolation transformer and common-mode inductor included in the second relay module effectively reduce electromagnetic interference, while the protocol conversion chip provides compatibility with multiple interface protocols, thereby comprehensively improving the charging efficiency and data transmission rate of the port expansion device. Compared with the prior art, this application solves the problem of limited signal quality under direct connection by adding a signal relay processing stage, enabling the port expansion device to have higher performance and a wider range of application scenarios.

[0072] In addition, this application also provides an embodiment of a port expansion device that uses the port expansion circuit described in the above embodiments.

[0073] It should be noted that the port expansion device can be designed with a metal casing, measuring 120mm × 80mm × 25mm and weighing approximately 150g. The casing is made of aluminum alloy with an anodized surface, providing excellent heat dissipation and wear resistance. The front of the device features power and status indicator lights, clearly displaying the device's operating status. The sides of the device have ventilation holes with a honeycomb design to increase the heat dissipation area and improve heat dissipation efficiency.

[0074] It should be noted that the main power interface of the port expansion device is located on one side of the device, using a USB Type-C interface that supports USB Power Delivery and accepts input voltages from 5V to 20V. A power switch is located next to the interface for manual control of the device's power on / off. The main data interfaces are located on the other side of the device, including three HDMI ports, one DisplayPort port, and one VGA port, supporting various video signal inputs.

[0075] It's worth noting that the power and data interfaces are located on the front of the device, including four USB Type-A ports, two HDMI output ports, and one RJ45 network port. The USB Type-A ports support the USB 3.0 standard, with a transfer rate of up to 5Gbps, and each port can provide a maximum output current of 900mA. The HDMI output ports support 4K@60Hz video output and are compatible with HDCP 2.2 content protection. The RJ45 network port supports Gigabit Ethernet, providing wired network connectivity.

[0076] It should be noted that the port expansion device integrates the port expansion circuit described in Embodiment 1, including a main power interface module, a first relay module, a slave power interface module, a main data interface module, a second relay module, and a slave data interface module. These modules are connected together via a high-quality PCB board to form a complete circuit system. The PCB board adopts a 4-layer design, with the signal layer and power layer separated to reduce interference and improve signal quality.

[0077] It should be noted that the device also integrates a temperature monitoring circuit and an overheat protection circuit. The temperature monitoring circuit monitors the internal temperature of the device in real time through a thermistor. When the temperature exceeds 70°C, the fan will be activated to accelerate heat dissipation; when the temperature exceeds 85°C, the overheat protection circuit will be triggered, automatically reducing operating performance or shutting down some functions to prevent damage to the device.

[0078] It should be noted that the power supply system of the port expansion device adopts a multi-stage voltage regulation design, including a primary filtering circuit, a DC-DC conversion circuit, and a secondary voltage regulation circuit. The primary filtering circuit consists of large-capacity electrolytic capacitors and ceramic capacitors, which can filter out the ripple and noise of the input power supply. The DC-DC conversion circuit uses a high-efficiency switching power supply chip with an efficiency of up to 92%, converting the input 5V-20V voltage into various voltages required by the device. The secondary voltage regulation circuit uses a low-dropout linear regulator to further improve the stability and purity of the power supply.

[0079] In practical use, users simply connect the port expansion device to a laptop or other device that supports USB Power Delivery via a USB Type-C cable. The device will automatically power on and negotiate power with the host. Users can then connect external devices such as monitors, keyboards, mice, and external hard drives to the various ports on the port expansion device, enabling multiple devices to be connected with a single cable. This design is particularly suitable for modern thin and light laptops, which typically have fewer ports; using a port expansion device can significantly increase the number of available ports and improve work efficiency.

[0080] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A port expansion circuit, characterized in that, The port expansion circuit includes: a main power interface module, a first relay module, and a slave power interface module; The main power interface module is connected to the first relay module and external power equipment respectively; The power interface module is connected to the first relay module and the device to be expanded, respectively. The main power interface module is used to realize power transmission and data transmission between external devices and the first relay module; The power interface module is used to realize power transmission and data transmission between the device to be expanded and the first relay module; The first relay module is used to filter, shape, and amplify the data signals transmitted from the main power interface module and the slave power interface module.

2. The port expansion circuit as described in claim 1, characterized in that, The port expansion circuit also includes: a master data interface module, a second relay module, and a slave data interface module; The main data interface module is connected to the second relay module and the external signal device, respectively; The data interface module is connected to the second relay module and the device to be expanded, respectively. The main data interface module is used to receive data signals sent by external data sources and transmit the data signals to the second relay module; The data interface module is used to transmit the data signal processed by the second relay module to the device to be extended; The data interface module is also used to receive feedback data signals from the device to be extended and transmit them to the second relay module; The main data interface module is also used to receive feedback data signals sent by the second relay module and transmit them to external signal devices; The second relay module is used to perform protocol conversion, data buffering, and signal enhancement processing on the data signals transmitted by the main data interface module and the slave data interface module.

3. The port expansion circuit as described in claim 2, characterized in that, The main data interface module includes multiple main data interfaces, each of which is connected to the second relay module and multiple external signal devices.

4. The port expansion circuit as described in claim 1, characterized in that, The first relay module includes: an offset submodule and an operational amplifier submodule; The operational amplifier submodule is connected to the bias submodule, the main power interface module, and the slave power interface module, respectively. The bias submodule is used to provide a bias voltage for the operational amplifier submodule; The operational amplifier submodule is used to amplify the data signal input from the main power interface module based on the bias voltage and transmit it to the slave power interface module.

5. The port expansion circuit as described in claim 4, characterized in that, The operational amplifier submodule includes: a first operational amplifier; The non-inverting input terminal of the first operational amplifier is connected to the main power interface module; The inverting input and output terminals of the first operational amplifier are connected to the power interface module. The controlled terminal of the first operational amplifier is connected to the bias submodule.

6. The port expansion circuit as described in claim 4, characterized in that, The bias submodule includes a voltage divider circuit or a voltage regulator chip, which obtains the bias voltage from the power transmitted through the main power interface module.

7. The port expansion circuit as described in claim 2, characterized in that, The second relay module also includes an isolation transformer, a common-mode inductor, and a protocol conversion chip; The isolation transformer is connected between the main data interface module and the slave data interface module to suppress common-mode interference; The common-mode inductor is connected in series in the data signal transmission path between the main data interface module and the slave data interface module to filter out high-frequency noise. The protocol conversion chip is connected between the main data interface module and the slave data interface module to support protocol adaptation from HDMI to VGA or from USB to RS485.

8. The port expansion circuit as described in claim 1, characterized in that, The main power interface module includes either a USB interface or a C interface.

9. The port expansion circuit as described in claim 2, characterized in that, The main data interface module includes one of an HDMI interface, a VGA interface, or a DP interface.

10. A port expansion device, characterized in that, The port expansion device uses the port expansion circuit as described in any one of claims 1 to 9.

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