TUSB8041: can VBUS external circuit be eliminated?

Yuan Tan63

Part Number: TUSB8041

Hi ,

Customer don't use VBUS and they don't have 5V supply. Can VBUS external circuit as below be eliminated? if not, how they design this with 3.3V supply?

and another question, if they don't need battery management, how should they deal with the pin in below pic:

thank you!

Yuan

over 5 years ago

0 Malik Barton57 over 5 years ago

TI__Guru 64326 points

Hi Yuan,

The USB_VBUS signal is necessary for default operation of TUSB8041. The resistor divider can be resized for 3.3V is a way such that Vh seen by the pin is greater than 450 mV. If power switching on the downstream ports is not implemented FULLPWRMGMTZ should be pulled high and GANGED can be left floating. FYI, Overcurrent reporting required for USB-IF Compliance.

0 Yuan Tan63 over 5 years ago in reply to Malik Barton57

TI__Expert 3280 points

Hi,

Thanks. but what Vh>450mV means? Does it mean that maximum of this two pin should be greater than 450mV?

Thank you!

Yuan

0 Malik Barton57 over 5 years ago in reply to Yuan Tan63

TI__Guru 64326 points

Hi Yuan.

450mV meas that upstream Vbus is in the valid range. Vh should only be seen by USB_VBUS and is the minimum voltage to establish a upstream connection. (Vh may be more accurately described as a threshold voltage (Vth).)

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TUSB8041: can VBUS external circuit be eliminated?