USB Power Delivery: Plugging into the Benefits

(aptiv.com)

14 points | by mooreds 3 days ago

4 comments

  • edent 1 hour ago
    I've basically stopped buying any portable electronics unless they take USB-C.

    Currently travelling with a laptop, watch, toothbrush, eReader, camera, bug-bite treater, and phone - all charging from the same power brick.

    I'm guaranteed of getting a replacement cable / charger wherever I am in the world if I need it.

    The only slight snag is some cheaper itema refuse to use PD and insist on plain 5V/2A - buy most decent travel chargers have NON-PD ports.

    Amusingly, most of the buses I've taken recently also have USB-C ports on them for ad hoc charging. Perhaps one day EVs will use USB-PD-Max rather than CCS :-)

    • ElijahLynn 40 minutes ago
      Same!

      I've also returned a few USB devices that ship with a USB-A to USB-C cable and ONLY charge in that mode, they also MUST charge with USB-C PD.

      The two so far were a therapy light and some Zippo hand warmers. Like, who in the hell would design a device that has a USB-C port on it where only a fraction of chargers will work on it. It feels even worse than proprietary charges, because you see a USB-C port on it and think, oh I have a plug that fits it, and then it doesn't F**ing work. Idiot engineering/product teams, making the world suck with their falsely advertised USB-C ports. If anyone of you are on a team that ever makes this decision, just know that it is a stupid decision, and jump ship when you can.

      • myself248 28 minutes ago
        The thing is, making a 5v-only device PD-compliant is literally one resistor. It costs well under a penny.

        It's pure ignorance, not a decision, but the lack of one. Lack of caring, lack of having an actual engineer involved, just slapping an oval-shaped port into a product where a trapezoidal port had been, and blindly thinking that magically makes it spec-compliant.

        Or not thinking about the spec at all.

        I return these devices too. Lots of them. My e-commerce returns over the last year are probably 50% PD non-compliance, 50% all other defects combined.

      • simoncion 21 minutes ago
        > I've also returned a few USB devices that ship with a USB-A to USB-C cable and ONLY charge in that mode...

        By "that mode", do you mean "1.5A @ 5V" permitted by BC, or do you mean "3A @ 20V" permitted by non-type-C PD?

        > Like, who in the hell would design a device that has a USB-C port on it where only a fraction of chargers will work on it.

        Who in the hell would design a charger that can do Type-C PD but can't do either pre-Type-C PD or BC? Does the charger in question also shit the bed when a USB 1.0 device attempts to draw 100mA @ 5V? I hope not! Were it me, I'd return that crappy thing for a refund.

    • ianburrell 9 minutes ago
      I think you are confusing the devices with USB-C that require USB-A, and devices that charge the standard USB-C 5V/3A/15W. The USB-A ones cheaped out in including the resistors that signal legacy USB mode, they work with the ones in the cable or adapter.

      Lots of people assume that USB-C always uses USB-PD, but the basic signalling is done with resistors. Lots of devices only need 15W, and it is better than USB-A charging. If you want faster charging, buy more powerful chargers.

    • mcsniff 15 minutes ago
      I'll bite. What type of watch do you have that has a direct USB-C port on it?
    • MrBuddyCasino 16 minutes ago
      You can always use a „PD Decoy“ if the voltage is USB compatible. A 5 / 9 / 12 / 15 / 20 Volt barrel plug is trivially USB powerable.
  • Animats 7 minutes ago
    240 watts over a USB-C connector? What next, USB toasters and coffee pots?
  • smallmancontrov 6 minutes ago
    Speaking of which, does anyone know a line of PD Decoy modules to convert barrel jacks to USB-C without the atrocious behavior of "oh, the charger doesn't have 12V, here's 9V have fun!" that the early ones all did? Ideally I'd like a little red light to come on or something, but I'd settle for not silently browning out the device.
  • hazkoulia 39 minutes ago
    I'm looking forward to USB-C PD small format factor PC's. A decent amount of room in the PC cases is taken up by the power supply. And if USB-C could somehow provide a range of voltages to the motherboard, SFFPC's could be downsized even more
    • exmadscientist 2 minutes ago
      > And if USB-C could somehow provide a range of voltages to the motherboard, SFFPC's could be downsized even more

      You reeeeeeally don't want to do that. Cable inductance is a big deal, among other issues. You want the main DC-DC regulators on the board, usually right at the load, for the main loads. Most of the PSU bulk is for dealing with mains itself: handling 50/60Hz or mains isolation is just physically large. Getting in secondary 20V DC (or so) from a single connector and then regulating it down on board is pretty much the ideal solution.

      (I can't even begin to comprehend the horrors of a USB-PD negotiation involving multiple voltages. It's already the worst standard I've ever had to deal with.* Don't make it worse!)

      (* Not hyperbole, it is truly, truly awful. At least things like 60601 are bad because, you know, they're covering lots of stuff like lifesaving medical devices. USB-PD is... holy hell, it is just bad.)

    • omh 23 minutes ago
      There are some SFF PCs that can take USB-C power.

      Lenovo have some,but sometimes require adapter cards. And a few of the Chinese N150 units will take PD power

      It's great for hot swapping and more portable than a laptop.