Robust cable-type detection for USB power delivery

摘要

A system and method for detecting a USB cable-type. A USB PD device configured at a near end of a USB cable is configured to (i) receive and process a signal from a device at a far end of the USB cable to determine a power rating of the USB cable and (ii) adjustably establish power delivered by the first device to the USB cable as a function of the determined USB cable power rating.

主权项

1. A system comprising:
a universal serial bus (USB) cable having a near end and a far end and including a Vbus wire; a first device having a receptacle configured to be coupled to the near end of the USB cable; and a second device configured to be coupled to the far end of the USB cable, the second device configured to generate a frequency shift keying (FSK) signal on the Vbus wire; wherein the first device is configured to determine a power rating of the USB cable by detecting a capacitor in the USB cable at the far end thereof coupling a portion of the FSK signal to another wire within the USB cable enabling the first device to receive and process the signal from the second device through the receptacle, the processed signal utilized to determine the current carrying capacity of the USB cable.