Hardware configuration with no USB and no bluetooth

RE: Hardware configuration with no USB and no bluetooth

ketiljo — Mon, 02 Dec 2024 09:28:50 GMT

No problem!

DCC can be left floating if you remove the inductor L2. The cap C3 is needed.

RE: Hardware configuration with no USB and no bluetooth

Luigi Antuono — Fri, 29 Nov 2024 15:01:05 GMT

I just realized I was confusing about what I said. Sorry for that.

What I meant is, because I will not use the radio features of the chip, can I have the DECR and DCC pins floating?

I am sorry that during the whole conversation (and also in the image I attached at the beginning) I was instead referring to DCCD and DECD, that was wrong of me.

RE: Hardware configuration with no USB and no bluetooth

ketiljo — Fri, 29 Nov 2024 08:02:26 GMT

The nRF5340 has two CPU cores. The application core is supplied via DECD and the network core is supplied via DECR. The radio is powered together with the network core. The main core is the application core so you will need this.

Now, the regulators have several modes. Then can operate in LDO mode and DCDC mode, where the latter requires the inductors to be in place. Since you're not using the radio, you can remove the inductor for the DECR DCDC (LDCC), but the regulator will need the capacitor to operate properly. For the lowest current draw, it's recommended to keep the DECD inductor (LDCCD).

RE: Hardware configuration with no USB and no bluetooth

Luigi Antuono — Thu, 28 Nov 2024 13:40:05 GMT

Hi ketiljo,

Thanks for the link you mentioned, but still, I am not sure if my question was clear enough.

Based on this block diagram:

If I won't use the radio features of the chip (so that VREGRADIO:DCDCEN will be low), can I left DCCD and DECD pins floating?

Are they used also to power other stuff other than the radio-related sections of the chip?

Thanks for your time.

Regards,

Luigi

RE: Hardware configuration with no USB and no bluetooth

ketiljo — Thu, 28 Nov 2024 11:57:28 GMT

Hi Luigi

You can see how the regulators are internally connected here:

https://docs.nordicsemi.com/bundle/ps_nrf5340/page/regulators.html

DECR and DECD each supplies the network and application CPU cores.

The ANT pin can be left floating when the radio is not used. Noot much else you can remove I'm afraid. Except the inductors if you don't need DCDC mode.

Best regards,

Ketil Aas-Johansen