What do you do with the USB pins if you are not using USB?

[Keith Brafford]

I am using the nRF52840 but am not using its USB peripheral.  Is it safe just to ground all the pins (D-, D+, VBus)?

[Simonr]

Hi Sebastian

Using the D+ and D- pins as vias (stepping stones) will be a no-go. There are parasitic diodes from D+/- to DECUSB. When VBUS is not connected, DECUSB is soft clamped to VSS, and it won't be acceptable to force D+/- high when VBUS is not connected.

Best regards,

Simon

[Sebastian_Fant]

Great thanks,