USB grounding when not used

[JRIIS]

NCR from UK would like to take the opportunity to ask a question related to the VDD_USB_CAP pin.

In the our documentation (IMXRT1060RM Rev. 3, 07/2021) shows that a capacitor connected to GND is needed for this pin (please see the image shown below).

NCR not planning to use the USB, so my question is: Can they leave VDD_USB_CAP pin floating?

Thanks,

/Jakob

[jingpan]

Hi @JRIIS ,

Please refer to RT1060 datasheet.

Unused pins: USB_OTG1_CHD_B, USB_OTG1_DN, USB_OTG1_DP, USB_OTG1_VBUS, USB_OTG2_DN, USB_OTG2_DP, USB_OTG2_VBUS, leave it as floating, not connected.
https://www.nxp.com.cn/docs/en/nxp/data-sheets/IMXRT1060CEC.pdf

Regards,

Jing

[JRIIS]

Hi Jing - Thanks for the information. Unfortunately, what you quoted on your email below does not make any reference to the VDD_USB_CAP pin. So I am afraid that the question if the VDD_USB_CAP pin can be left unconnected still remains.

Could I kindly ask to look at this again please?

Thanks,

/Jakob

[jingpan]

Hi @JRIIS ,

You can keep USB pins floating. If  USB VBUS is not applied, there is no need to connect the VDD_USB_CAP.

Regards,

Jing