USB Port Related

Powered vs non-powered USB hub
What are the maximum power output and Data Transfer Rates for the USB Standards?

Not yet: supercharge

Non-Powered vs Powered USB Hub

Source: https://www.cmd-ltd.com/advice-centre/usb-chargers-and-power-modules/usb-and-power-module-product-help/powered-or-unpowered-which-usb-hub-should-you-buy/

Non-powered:

  • Plug into a computer's USB port
  • Draw power from its battery
  • Is usually used when:
    • using devices that need only low voltages, e.g.
      keyboards & mice, smartphone chargers, flash drives, game controllers
  • If used with a high-voltage device:
    • drawing power away from the computer
    • can cause it to underperform
  • (+) : compact, portable, cheaper, no need to find a power outlet
  • (-) : can't power high-voltage devices w/o performance issues, struggle to power several devices at once

Powered:

  • Come with their own AC adapter
  • Plug into the mains
  • Is needed when:
    • running several devices at once
    • running devices that operate on higher voltage, such as:
      • external hard drives
      • printers
      • scanners
      • (added by N) monitor! –
        -> if USB hub is not powered: flickering
  • (-) : more expensive, need access to a mains socket

What are the maximum power output and Data Transfer Rates for the USB Standards?

source: https://resources.pcb.cadence.com/blog/2020-what-are-the-maximum-power-output-and-data-transfer-rates-for-the-usb-standards

  • USB: Universal Serial Bus
  • USB 3.0
    • Data rate speed: 10 Gbps
    • Bus power: 900 mA
  • Data rate speed comparison
    • USB 1.0: 1.5 Mbps
    • USB 1.1: 12 Mbps –> keyboards, mice, printers
    • USB 2.0: 480 Mbps –> flash drives, external HDD
    • USB 3.0 and USB 3.1: 5 Gbps
    • USB 3.2 gen 2: 10 Gbps
  • Maximum power output standards
    • USB 1.0 & 2.0:
      • downstream port:
        • up to 0.5 mA
    • USB 3.0:
      • ? 0.9 mA (translates into 4.5 watts –> rating based on the 5 volts standard output)
      • charging downstream ports:
        • 1.5 A (translates into 7.5 watts)
    • USB 3.1:
      • up to 3A
  • Functionality (except Apple):
    • data transfer
    • power transfer (charging)
      • some cables are strictly designed for power transfer only
        & lack the wiring for data transfer
        e.g, for power banks
    • even sharing network connection (tethering)