What this USB controller handles on the I²C bus
The STUSB4710AQ1TR is a dedicated USB controller from STMicroelectronics that manages USB Power Delivery negotiation over an I²C interface, offloading the PD protocol stack from the host MCU. It accepts a supply between 4.1V and 22V, which covers the full USB VBUS range from standard 5V to 20V PD, so no external regulator is needed between the VBUS rail and the controller.
Why the 4.1V–22V supply range matters for your rail budget
The lower threshold of 4.1V means the part stays alive even when VBUS droops under load, common in long USB cables or high-current charging. The 22V ceiling covers the 20V PD profile with margin — no need for a pre-regulator or zener clamp on the supply pin. This simplifies the BOM by one IC and its associated passives.