AMD Framework USB-C charger compatibility issues

Community Support
189

My previous replies are outdated. Recently I found that the laptop supports 5V3A PD charging. I made the test using a 24VDC5525 to USB PD 100W converter. This device is step-down i.e only reduces voltage. So I used a bench power supply to input 7.5V, the only PD protocol below 9V is 5V3A. For some reason the USB meter won’t work as it’s internal resistance makes the current unstable and the converter emits high-pitched whine, but without it the laptop draws about 5V2.7A and the bench power supply outputs about 14.8W(the DC to PD converter has about 90% efficiency).

5VPD input w/USB meter

idle5Vmeterunstable
idle5Vmeterunstable846×137 14.8 KB

5Vmeter
5Vmeter1020×768 102 KB

5VPD input w/o USB meter

idle5Vnometerstable
idle5Vnometerstable846×137 15.2 KB

7.5Vbench
7.5Vbench1040×783 183 KB

The current increase from the input power is consistent with the charging power increase on btop

My finding is not very useful since most, if not all, PD chargers are at least 9V2A18W, I can’t find any 5V3A PD charger on the market, the 5V1A, 5V2A, 5V2.1A, 5V2.4A etc. they are all non-PD. The laptop only supports PD protocol, it won’t draw current from a non-PD charger even said charger current is higher than 3A.

EDIT: Didn’t work, when plugged into a real 5V3A socket (it’s possible to find one, this time is on a train), the laptop only pulled 2.7A for less a second before ignoring it(the charge light flickered once).

190

5V 3A USB-C PD chargers are common although they usually also support higher voltage profiles (so won’t be preferred by the framework laptops). Raspberry Pi LTD even has a USB-C PD charger that supports 5V 5A (with additional higher voltage profiles as well).

191

Sorry for the misunderstanding. I was trying to say that it’s hard to find a 5V3A ONLY power supply. Since most PD power supplies that capable of 5V3A also have higher power outputs, the laptop will request a higher power instead of 5V3A, making it difficult to tell whether the laptop supports 5V3A PD input

192

There are tons of 5V 3A only pd power supplies, just not ones that use digital pd negotiation as 5V 3A is the max you can do using resistor based pd negotiation.