Power Delivery Capabilities of USB-C Ports on Dell Laptops
概要: This article discusses the power delivery capabilities of the USB-C Ports on Dell laptops.
現象
Affected Platforms:
- Latitude
- Precision Mobile Workstations
- Alienware Laptops
- Vostro Laptops
- Inspiron Laptops
- XPS Laptops
Users may believe that the USB-C ports are a way to supply higher voltage or current to USB devices, Following the USB Power Delivery specification.
USB-C devices requiring higher voltages or current may not work properly without an additional power source other than the computer (this could be from AC adapter or battery).
原因
Dell laptops follow the Dell power policy, limiting the power supply capabilities to 5V voltage and a maximum current of 3A.
解決方法
The USB-C (including Thunderbolt3 and Thunderbolt4) devices can act as a power supply and a power consumer. Dell Laptops accept various power delivery voltages and currents from AC Adapters, docking stations, and monitors with Power Delivery capabilities, but only supply a single voltage (5V and a maximum current of 3A).
The laptop does not offer multiple voltages and currents like a typical power source (AC adapter, dock, or monitor).
If the laptop has more than one USB-C port, the sequence of attaching devices to these ports is important as secondary or third ports may then supply less current to the secondary or third attached device.
Laptops with the USB-C Power BIOS setting (with the option 15W and 7.5W) can limit the current on the ports to 1.5A (7.5W) for power saving reasons.
Laptops acting on battery mode may behave differently than when plugged in.
The capabilities differ from platform to platform, due to different numbers of ports, different Power Delivery controllers, internal power management, and the maximum power consumption of the laptops themselves.
Not all USB-C devices adhere to the Power Delivery specification and do a handshake with the Laptops Power Delivery controller and assume the typical 5V and 3A is supplied, in relation with the above this may lead to devices not working properly.