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HD3SS3220: UFP, what voltage level on CC1 and CC2?

Part Number: HD3SS3220

Hi,

I'm trying to debug a design that doesn't seem to be working.

What voltage level should I see on CC1 and CC2 when the cable is plugged in in both orientations? I have two board built and both work differently.

The design is self powered and thus does not take any power from VBUS. I read (somewhere) that there was a minimum capacitance retirement for the VBUS line in the USB spec, so I added 2 x 22uF caps to the design. This meant that when the cable was removed the voltage on VBUS fell very slowly. For now I have fitted a 10k resistor in parallel with one of the 22uF capacitors. What is recommended for capacitance on VBUS if the device takes no power from the upstream device?

Thanks,

Graham