Post #3289080

2026-06-07 18:00 UTC

@isagalaev@mastodon.social @valpackett@social.treehouse.systems It enables a higher charging rate in devices that can draw more than the default limit but don’t bother including those resistors, which act as a signal to the power source. longer: https://chaos.social/@gsuberland/116709994257007906

Replies (2)

@isagalaev@mastodon.social 2026-06-07 18:11

@grumpybozo@toad.social @niconiconi@mk.absturztau.be but wouldn't higher current "fry" the device? Or is it ultimately controlled by the device, and it just doesn't request more power when the resistors are absent?

Open ##3289081
@niconiconi@mk.absturztau.be 2026-06-07 18:43

@grumpybozo@toad.social @isagalaev@mastodon.social @valpackett@social.treehouse.systems No, this is not correct. The CC1/CC2 resistors are not just used in the Power Delivery extension, but are also a mandatory part of the USB-C base spec. The use is required. If CC1/CC2 are open circuits without resistors, the USB-C source is required to treat the port as "not connected", as a result no power is applied. See "4.5.1.2.1. Detecting a Valid Source-to-Sink Connection", "Table 4-10 Source Perspective" and "Table 4-11 Source (Host) and Sink (Device) Behaviors by State" of Universal Serial Bus Type-C Cable and Connector Specification (rev 2.0, 2019).

Open ##3289085