Dual-Mode USB Interface Switching DC and AC Coupling
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Solution Overview
Problem
The existing USB2.0 technology has limitations in transmission distance and compatibility, restricting its application due to strict ground potential differences and maximum cable length of 5 meters, which hinders its use in long-distance data transmission and compatibility with extended modes.
Innovation Solution
A dual-mode USB device that incorporates a USB2.0 controller and a dual-mode USB2.0 interface module, allowing the USB interface to switch between DC coupling for standard USB2.0 mode and AC coupling for extended mode, enabling compatibility with both standard and extended USB2.0 protocols, thereby expanding the application range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If DC coupling is used for USB2.0 standard mode, then compatibility with standard USB2.0 equipment is improved, but transmission distance is limited to 5 meters
Solution Approach 1:
The USB interface module dynamically switches between DC coupling mode for short-distance standard USB2.0 compatibility and AC coupling mode for long-distance extended mode communication. The system adapts its coupling type based on the remote equipment's capabilities, enabling a single interface to serve both short and long transmission distance requirements.
Solution Approach 2:
The USB interface module is designed with multi-functionality to support both DC coupling and AC coupling modes simultaneously. This universal design allows the same physical interface to be compatible with both standard USB2.0 equipment (5m limit) and extended mode equipment (50m+ capability), eliminating the need for separate interfaces for different distance requirements.
2Length of stationary object
If AC coupling is used for extended mode, then transmission distance exceeds 50 meters, but compatibility with standard USB2.0 equipment is reduced
Solution Approach 1:
The system dynamically selects the appropriate coupling mode based on the remote equipment type. When connecting to standard USB2.0 equipment within 5 meters, DC coupling is activated for optimal compatibility. When connecting to extended mode equipment requiring 50+ meters, AC coupling is activated to enable long-distance transmission.
Solution Approach 2:
The USB interface module incorporates both DC coupling and AC coupling capabilities within a single unified interface design. This multi-functional approach ensures that the interface can universally connect to both standard USB2.0 devices and extended mode devices, with the appropriate coupling type automatically or manually selected based on the connection requirements.
3Reliability
If strict ground potential difference requirements are enforced, then signal transmission stability is improved, but application range is restricted to short distances
Solution Approach 1:
The system changes the ground potential difference parameter dynamically based on transmission distance and equipment type. For short-distance standard USB2.0 connections, strict ground potential matching is maintained to ensure signal stability. For long-distance extended mode connections, the ground potential difference requirement is relaxed or eliminated through AC coupling, enabling applications up to 50+ meters while maintaining acceptable signal integrity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The dual-mode USB device enhances compatibility and reduces user complexity and costs by allowing the same USB interface to work with both standard and extended mode equipment, increasing the transmission distance and interference resistance.
Implementation Method 1
in the USB2.0 standard mode, the DP and DM signals of the USB2.0 interface are connected with the remote USB interface by DC coupling
Implementation Method 2
in the USB2.0 extended mode, the DP and DM signals of the USB2.0 interface are connected to the remote USB interface by AC coupling
Data Source
AI summary
The present invention discloses a dual-mode USB device, which includes a USB2.0 controller, a dual-mode USB2.0 interface module and a USB interface. The dual-mode USB device alternatively works in a USB2.0 standard mode or a USB2.0 extended mode. In the USB2.0 standard mode, DP and DM signals of the USB2.0 interface are connected to a remote USB interface by DC coupling, and is compatible with remote devices using USB2.0 standard signals and protocols; in the USB2.0 extended mode, DP and DM signals of the USB2.0 interface are connected to the remote USB interface by AC coupling, which is compatible with remote devices supporting the USB2.0 extended mode.