STUSB4500 No Power

[mobrien]

Hello All,

 

I’m working with a STUSB4500 chip and have hit an issue right from the get go. For reasons I can’t see, the chip is not being powered when connected to a USB-C source. Probing VDD shows continuity to VBUS, and probing GND shows good continuity to the power source GND. I’ve attached my schematic below. Any ideas where I messed up?

 

 

[mobrien]

I might have found what I did. The USB-C Source is a “cold socket” during the initial connection. If I’m not mistaken this means I need to use dead battery mode and connect the CC1DB pin to CC1?

[Didier HERROUIN]

Dear mobrien,

All the USB-C chargers are supposed to be “cold socket”, meaning that they should not deliver any voltage when no Sink is connected.

Nevertheless, your suggestion is correct : as you device (Sink) is directly supplied by VBUS, you must enable the dead battery mode by connecting CC1DB to CC1 and CC2DB to CC2.

Regards.

[mobrien]

Didier,

 

Thank you for the confirmation.