TUSB320: CC left open function

You can control VBUS power by ID pin.

in DFP, ID is high when CC floating and Vbus switch is off. ID is low when UFP attached and turn Vbus on.

in UFP, ID always high and Vbus switch is off, Vbus is get from USB connector.

Is this answer your question?

Best

Brian

The customer scenario is as shown below.

1. TUSB320 is placed on SINK side. His application is SINK.

2. His SINK products is supplied VBUS power from any SOURCE product. CC is 5.1k-ohm pulled down to GND.

3. To cut VBUS power off from his SINK product, his SINK product forces CC open state.

4. Finally VBUS power supply from SOURCE cut off.

I am not sure the customer SINK product has internal power supply but please suggest if TUSB320 supports above way. Or USB-C protocol can support this way.

Best regards, 

Yes. This is TUSB320 UFP use case.

Please let us know the way of CC while VBUS power supplied by DFP or Source.

How can TISB320 support following use case.

1. TUSB320 is placed on SINK side. His application is SINK.

2. His SINK products is supplied VBUS power from any SOURCE product. CC is 5.1k-ohm pulled down to GND.

3. To cut VBUS power off from his SINK product, his SINK product forces CC open state.

4. Finally VBUS power supply from SOURCE cut off.

regards,

UFP should meet all these conditions, UFP get Vbus from source product though type-C connector.

Best

Brian

Is DISABLE_RD_RP bit able to do that.

why does customer want to disable  Rd/Rp?

Bes

Brian

as i mentioned, leaving CC pin open to kill VBUS supply from Sink side. This is the reason.

anyway, you should have answer our customer question first. Is DISABLE_RD_RP bit can support CC pin open.

I understood that setting DISABLE_RD_RP=1 makes CC left opened.

let me know if my understanding is incorrect.