TUSB9261: Unused HS Pins

Mark Rice

Part Number: TUSB9261

Hello,

My device is using a SATA SSD and the application processor communicates to it over SS USB through the TUSB9261. I plan to make the TUSB9261's HS interface available to an external PC so the Flash can be programmed during development, but only the SS lines will be connected to the APQ during normal operation.

My question is, will this cause some problem if only the SS lines are connected to the TUSB9261 and the HS lines are unused?

Also, does this change the way the VBUS detect pin on the TUSB9261 should be used? i.e. permanently held to 0.5V by voltage divider? Only HS USB connected should raise this pin voltage?

I couldn't find much information in the datasheet regarding this.

Thanks,

Mark

over 8 years ago

0 Elias Villegas M. over 8 years ago

TI__Guru* 76130 points

Hello,
It is possible to only connect the SS lines although that would be non-USB compliant.
If you split the HS and the SS interface you may only have one USB Host active at a time.
The USB_VBUS pin shall be kept stable per the datasheet specs no matter if the connection is SS or HS.
Regards

0 Mark Rice over 8 years ago in reply to Elias Villegas M.

Prodigy 90 points

Ok,

I will ensure that only one interface is used at a time during development and that VBUS is kept stable.

Thanks for your response!

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TUSB9261: Unused HS Pins