12-11-2020, 03:30 AM
(12-06-2020, 04:54 PM)KC9UDX Wrote: The PBP currently (pun?) only draws about 2.5A from the USB-C connector in any case. Except for future modifications, more than 15W won't do any good. Reports are that it draws closer to 3A from the barrel jack; and the power circuitry would need a major redesign to accept more than that.
I don't think it would be a major redesign. The main power supply, a BQ24171, is rated to 17V. It should be possible to get 45W with 15V-3A over USB-C with only minor changes to a few components.
(12-07-2020, 09:58 PM)calinb Wrote: I still don't know what PD modes the dock will request. This power supply supports more modes than most. I wonder if it would work. The power supplies I've seen all peak at 3 or 3.25A so 20 V would be required to make it to the 60W dock spec.The USB PD spec allows up to 3A without a fancier cable that has a chip in it. So usually a power supply with top out at 3A. Only for >60W will >3A be used, since the max voltage is 20V and it's required.
Input: 100~240V / 50~60Hz; Output: 65W, 5V-3A, 9V-3A, 12V-3A, 15V-3A, 18V-3A, 20V-3.25A
The spec only requires voltages of 5V, 9V, 15V, and 20V, and only if the adapter is powerful enough to reach 3A at the previous voltage. So the 12V and 18V are optional voltages that adapter has that will be less common.
I wonder if the schematic for the dock will be available. I've never worked on hardware with an externally powered USB hub and don't know what's done. Does it have a buck-boost supply to allow any combination of input and output voltage? Or does it just have a buck converter to 5V, so you can get either 5V or the input voltage? Do they do dynamic power management as new USB-PD devices are attached?