3 ms·

Some of these values are determined only after hooking the devices together. The devices may support 5V/5A (25W) but cable may only support 3A (but it can do 36

• Dylan16807 6y ago
  A device using 5V/5A is nonstandard to an ugly extent but that's fine, because the actual spec of the cable is amps and there are only two options: 3 amps and 5 amps. And we could fold the thunderbolt/bandwidth/video into one single speed rating without much trouble, if the desire was there...
  • megous 6y ago
    What exactly is non-standard about it? https://megous.com/dl/tmp/a0538dc39724eb2e.png https://megous.com/dl/tmp/a0538dc39724eb2e.png
    • Dylan16807 6y ago
      https://images.anandtech.com/doci/11181/USB-PD.png https://images.anandtech.com/doci/11181/USB-PD.png https://i.stack.imgur.com/W8UGp.jpg https://i.stack.imgur.com/W8UGp.jpg Once you hit the soft cap of 3 amps, you're supposed to increase the voltage. The 3-5 amp range is only supposed to be used at 20 volts.
      • megous 6y ago
        That's all good if your sink supports sinking 20V, but some don't. Anyway, those tables describe minimum required currents for a given PDP: https://megous.com/dl/tmp/a4111a84934c8c8f.png Sources can support more and it's not against the spec, as long as you detect the 5A cable. https://megous.com/dl/tmp/1eccbf102295a676.png
        • Dylan16807 6y ago
          > That's all good if your sink supports sinking 20V, but some don't. It's not like you go directly to 20, you go one step at a time. > Sources can support more and it's not against the spec, as long as you detect the 5A cable. They can but how many do? If you want to play nice you shouldn't require that for your device.