nrf5340 USB connection reference schematic

[Agoff]

Hi ,

can I connect nrf5340 pins D+and D-  to the  USB directly only via voltage translator from USB 5V to the nrf5340 1.8V main power?

Do you have a reference design for this purpose?

 

[Agoff]

Additionally, what is the minimum voltage level for the first programming? In the previous design with nRF52832, I encountered the problem when the initial programming voltage level was at least 2.5V. But power management circuit has started with 1.8V and only after uploading the FW might reconfigure the management circuit to 3V.

[Priyanka]

Hi Alex,

I am sorry but could you be a bit more clear on your first query? If it is whether the D+ and D- can be directly connected to 5V, then NO.

And you can also refer the VBUS detection specifications.

Further details are also available in the USBD documentation.

Best Regards,

Priyanka

[Priyanka]

You need to connect 5V USB supply to the VBUS (B11 in your case). You can refer the recommended operating conditions.

But yes, you can connect VDDH and VBUS pins together according to the reference circuit design.

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You can read more about USB regulator support too.

-Priyanka

[Agoff]

Do I need to use a USB detection circuit or I can skip it without? 

[Priyanka]

No, you don't need an extra USB detection circuit as there is a detection event that is being triggered when you set 5V on the VBUS pin. A 4.7uF capacitor must also be added to the DECUSB pin in addition to VBUS and the data pins when using USB.

[Agoff]

Dear Priyanka,

can you please take a glance at the design?

 NRF5340.pdf

[Priyanka]

Hi Alex,

The RF design is different from the our reference design and we would usually recommend to follow those. Also, the DECR and the DECRF is shorted in the reference design.

-Priyanka