Please re-read what I wrote and you quoted. Clearly, the 1A6 requirement for downstream USB is a design goal.Err, no. Only if you want the full 1.6A (8W) for downstream bus powered USB devices. If you can work with 600mA (3W) or don't need the full 17W for the PI and HATS, 5v/3A (15W) is fine. FWIW, I've booted lightly loaded Pi5 off an 8W supply - the USB port of another Pi5.The Pi5 clearly needs more than 15W to implement its design goals with the available (affordable) silicon.
Of course, you can use any decent USB-PD supply if you are not exceeding the 3A it will provide, but also, of course, 3A (0A6 downstream) was not an adequate specification for use with an unspecified USB load. (Given the USB spec, I'm not sure that 1A6 across four downstream sockets is really suitable either, but that is a specified limit that most of us can work with.)
I agree entirely that, if power requirements increase further, a new power input at a higher negotiated voltage probably will be necessary -- or more clever engineering. Or unicorn-derived magic.
Statistics: Posted by davidcoton — Thu Jan 02, 2025 9:29 pm