TUSB8044A: TUSB8044A in VBUS Source Application

HI Austin:

    Voltage on USB_VBUS is between 500mV to  1V, so after voltage divider , voltage need to meet above spec.

Best

Brian

Thanks for the reply! The issue is that the host can negotiate VBUS to anywhere between 5V and 20V. Because of that range, I can't simply use a voltage divider. The datasheet suggests the PD controller could be used to control the signal instead. Is that something that could be done with the TPS26744E?

Austin

Hi Austin:

   You can just connect  hub USB_Vbus  to a fixed supply like 5v or 3.3v though a voltage divider. so you don;t need to worry about 20V vbus.

Best

Brian

This seems to contradict an earlier forum discussion:  TUSB8044A: USB_VBUS pin connection purpose 

The concern there was that the USB_VBUS signal is supposed to indicate when the host is on and ready to connect to the hub. Is there a GPIO function on the TPS26744E PD controller to do this?

Hi Austin:

   I'm not PD controller expert. But PD controller  should know when hub is connected to host based on CC communication. then you can use that signal to control the fixed voltage used for USB_Vbus voltage divider.

Best

brian