USB Connector Power Delivery via I2C Negotiation
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Solution Overview
Problem
The USB standard limits the current specification for electric power delivery, making it impossible to power external devices that require higher currents without a separate power source, even with the upgraded USB 3.0 standard, which only increases the current from 500 mA to 900 mA, still falling short for high-power devices like displays.
Innovation Solution
An electronic device with a USB 3.0 connector and a power supply unit that judges the connected device's compatibility with the USB 2.0 standard, using additional terminals for communication and power delivery beyond the USB 2.0 specification to supply the requested voltage and current to compatible devices, allowing for increased power delivery while maintaining USB standard compliance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a USB standard interface is used to connect external devices, then compatibility and ease of operation are improved, but the available electric power is limited by the USB current specification
Solution Approach 1:
The invention segments the USB connector into two functional parts: the first four terminals follow the USB 2.0 standard for data communication and limited power supply, while the additional fifth terminal is specifically added for I2C communication to enable high-power device identification and control. This segmentation allows the system to maintain USB standard compatibility while extending power delivery capabilities through dedicated power supply circuitry controlled by the I2C interface.
2Power
If the USB current specification is increased from USB 2.0 to USB 3.0, then available electric power is improved, but it still falls short for high-power devices like displays
Solution Approach 1:
The invention introduces an intermediary I2C communication interface using the fifth terminal as a mediator between the host device and high-power external devices. This intermediary layer enables the host to identify connected devices, negotiate power requirements, and control power delivery beyond standard USB limitations, while maintaining compatibility with both USB 2.0 and USB 3.0 devices through the dual-terminal approach.
3Power
If additional terminals are added to the USB connector for I2C communication, then power delivery capability is improved, but device complexity increases
Solution Approach 1:
The fifth terminal serves multiple functions: it acts as a data line for I2C communication during device identification and negotiation, and simultaneously serves as a power supply terminal for delivering high current to external devices. This multi-functionality reduces the need for completely separate communication and power circuits, thereby limiting the increase in overall device complexity while achieving enhanced power delivery capability.
Data Source
AI summary
An electronic device includes a USB connector, a power supply unit for supplying electric power to an external device, which is connected via the USB connector, a judgment unit for judging whether the external device is a device being compliant with a USB 2.0 standard or a compatible device being compatible with a device complying with the USB 2.0 standard; and an acquisition unit for acquiring a value of voltage requested by a connected compatible device by communicating with the connected compatible device when the judgment unit judges that the external device is the compatible device; wherein the power supply unit supplies electric power corresponding to the value of voltage acquired by the acquisition unit to the compatible device when the judgment unit judges that the external device is the compatible device.