i.MX8Mplus USB1_VBUS characteristics

[max123]

Hi,

in my design, USB1 is used as device. For this reason, VBUS-sensing is reqired.

I cannot find the characteristics of USB1_VBUS in the datahsheet. Is it possible to sense VBUS using a resistive voltage divider? In this case, a small current could be injected into this port, if VDD_USB_3P3 is down.

Or do i need to treat USB1_VBUS as 3.3V-port with special function, requiring a external logic gate or comparator?

[Rita_Wang · Accepted solution]

The USBx_VBUS pin cannot directly connect to 5 V VBUS voltage on the USB2.0 link, each
USBx_VBUS pin must be isolated by an external 30 K 1% precision resistor if connects to 5 V VBUS.