Custom PCB & is it okay to run SPI at 1.8V?

RE: Custom PCB & is it okay to run SPI at 1.8V?

ryerye120 — Mon, 29 Mar 2021 19:39:58 GMT

Ahh okay! So I'm trying to see which circuit config I can use on my PCB. Since I'm operating everything on 1.8 V I probably don't need anything fancy so would circuit config 3 work for my custom design? Where VDD would just be 1.8V. Since I don't need to step any voltages up/down I don't think I really need the DCDCEN0/1.

Taken from: infocenter.nordicsemi.com/index.jsp

RE: Custom PCB & is it okay to run SPI at 1.8V?

ketiljo — Fri, 19 Mar 2021 11:40:12 GMT

Sure, the chip can operate from 1.7 to 3.6 V in normal mode: https://infocenter.nordicsemi.com/topic/ps_nrf52840/power.html#unique_1730776566

There are internal regulators for the different power domains. The radio operates at a lower voltage so the performance remains the same within the operating voltage range.

RE: Custom PCB & is it okay to run SPI at 1.8V?

ryerye120 — Fri, 19 Mar 2021 02:23:45 GMT

I can just run the entire chip off of 1.8V? Will this affect Bluetooth at all?

I'll open a private case when I'm ready!

Thank you so much!

RE: Custom PCB & is it okay to run SPI at 1.8V?

ketiljo — Thu, 18 Mar 2021 08:24:23 GMT

1. Just connect VDD to VDDH and supply both with 1.8 V. See https://infocenter.nordicsemi.com/topic/ps_nrf52840/power.html#unique_1386123489, figure 1.

REGOUT0 is only in use in the high voltage mode, where you have a higher voltage on the VDDH pin only.

2. Open an new, private case and ask for a review. Attach the schematic as pdf and the layout as gerber files.