AM3352: USB_VBUS voltage levels

Alberto Soattin

Part Number: AM3352

Hi Support,

my customer would like to better understand logic levels for USB1_VBUS pin.

What is the minimum voltage to be provided at the pin in order to understand if 5V are present at USB1 port? Are 3,3V enough?

Thanks and regards,

alberto

over 7 years ago

0 Biser Gatchev-XID over 7 years ago

TI__Guru**** 393215 points

No, actual VBUS voltage must be present on the pin.

0 Alberto Soattin over 7 years ago in reply to Biser Gatchev-XID

TI__Genius 16905 points

Biser,

it's ok to bring VBus to that pin, but is 3,3V enough? On the Data Sheet we say in fact "Comparator Input Votlage from 0 to 5V"
Thanks
Alberto

0 Bin Liu over 7 years ago in reply to Alberto Soattin

TI__Guru**** 177641 points

Alberto,

Yes, the VBUS_IN pin can take 0~5V, but the USB controller will only be functional when the voltage is above VBUS_VALID threshold, which is 4.4v defined in the USB Spec.

0 Bin Liu over 7 years ago in reply to Alberto Soattin

TI__Guru**** 177641 points

By the way, the VBUS_IN should be directly connected to the VBUS pin of the USB port, and/or the output of the usb power switch. In either way, VBUS_IN pin should be 5v when VBUS presents, 3.3v shouldn't be in the picture.

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AM3352: USB_VBUS voltage levels