TUSB320: How CC pin's behaviour without VDD

YUTAKA DOHI

Part Number: TUSB320

Hi,

I'd like to use TUSB320 for a UFP system without battery, in order to sense the supply ability of DFP. It's meant no VDD comes from other than VBUS, which would come after the DFP sensed Rd.

Do Rds in TUSB320 terminate CC lines without VDD? Diode D1 in figure 8-11 of datasheet seems to sugest such usage.

Ofcourse, descrete resisters and voltage comparators can be configured those functionality, but TUSB320 is enough cost & area efficient v.s. descrete circuits. :-)

Thanks.

over 2 years ago

+1 Brian Zhou over 2 years ago

TI__Guru*** 145215 points

During dead battery mode, VDD is not available. CC pins always default to pulldown resistors in dead battery
mode. Dead battery mode means:
• TUSB320 in UFP with 5.1-kΩ ± 20% Rd; cable connected and providing charge
• TUSB320 in UFP with 5.1-kΩ ± 20% Rd; nothing connected (application could be off or have a discharged battry)

0 YUTAKA DOHI over 2 years ago in reply to Brian Zhou

Prodigy 10 points

Thank you very much, Brian.
Ah, section 7.4.3 of the datasheet. This is the same as a system without battery.
Thanks again to all.

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TUSB320: How CC pin's behaviour without VDD