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This is incorrect. A USB-C power source can’t be in-spec if it doesn’t supply 5V by default. Other voltages or alt modes can be negotiated after that, but eve

by nrp 3y ago

This is incorrect. A USB-C power source can’t be in-spec if it doesn’t supply 5V by default. Other voltages or alt modes can be negotiated after that, but everything starts at 5V. This is defined in the base “ Universal Serial Bus Type-C Cable and Connector Specification”, not the optional USB-PD spec.

mike_d 3y ago
A common misconception, Wikipedia spells it out maybe clearer than I did: "A device with a Type-C connector does not necessarily implement any USB transfer protocol, USB Power Delivery, or any given Alternate Mode: the Type-C connector is common to several technologies." The document you mention is the specification for implementing USB 3.0 on a USB type C connector.
- nrp 3y ago
  That’s not correct. We’re USB-IF members, and I’ve read through large chunks of USB-IF specs. The spec I am referencing is the one that defines the actual connector. You cannot build a power source that uses a USB-C connector and doesn’t support 5V and call it “USB Type-C”.
  - mike_d 3y ago
    > We’re USB-IF members I hope so that you can pressure the Promoter Group into not making the same mistakes with USB-D. :) Have a look at https://web.archive.org/web/20161220102924/http://www.usb.org/developers/presentations/USB_DevDays_Hong_Kong_2016_-_USB_Type-C.pdf https://web.archive.org/web/20161220102924/http://www.usb.or... slide 45. Note how all the power requirements also list an associated USB spec. Looking back I will give you that 5v is required for vconn. > You cannot build a power source that uses a USB-C connector and doesn’t support 5V and call it “USB Type-C”. Yet this whole conversation thread shows that is not the case. By not joining the IF you can do as you please. A great example of this is the Ubiquti Theta cable (https://tinyurl.com/5asf8wpp https://tinyurl.com/5asf8wpp) where they implemented a completely proprietary cable (as far as I can tell) with "USB Type-C" on both ends.

by nrp 3y ago

mike_d 3y ago

A common misconception, Wikipedia spells it out maybe clearer than I did: "A device with a Type-C connector does not necessarily implement any USB transfer protocol, USB Power Delivery, or any given Alternate Mode: the Type-C connector is common to several technologies." The document you mention is the specification for implementing USB 3.0 on a USB type C connector.

nrp 3y ago
That’s not correct. We’re USB-IF members, and I’ve read through large chunks of USB-IF specs. The spec I am referencing is the one that defines the actual connector. You cannot build a power source that uses a USB-C connector and doesn’t support 5V and call it “USB Type-C”.
- mike_d 3y ago
  > We’re USB-IF members I hope so that you can pressure the Promoter Group into not making the same mistakes with USB-D. :) Have a look at https://web.archive.org/web/20161220102924/http://www.usb.org/developers/presentations/USB_DevDays_Hong_Kong_2016_-_USB_Type-C.pdf https://web.archive.org/web/20161220102924/http://www.usb.or... slide 45. Note how all the power requirements also list an associated USB spec. Looking back I will give you that 5v is required for vconn. > You cannot build a power source that uses a USB-C connector and doesn’t support 5V and call it “USB Type-C”. Yet this whole conversation thread shows that is not the case. By not joining the IF you can do as you please. A great example of this is the Ubiquti Theta cable (https://tinyurl.com/5asf8wpp https://tinyurl.com/5asf8wpp) where they implemented a completely proprietary cable (as far as I can tell) with "USB Type-C" on both ends.