Hi, guys! Thanks for your replies!
I’ve found that topic in the nrf52840 datasheet and read through it.
I think, that in the final design I may also go with the Normal mode, but I just power-up the chip with 2.5V. Hence, I’ll have GPIO level at 2.5V as well. Most probably this is the easiest scenario. As I understand, in this case I can go with the LDO, as the power saving with using DC-DC converter will be neglectible.
In contrary, if I decide to power up the chip with 5V, then I have to go for the Regout0 option to step down the voltage to 2.5V an use the DC-DC converter, since the difference between Vin and GPIO voltage is drastic.
However, since my system is 2.5V compatible, I believe the option to select is evident.
As I understand, this is also something I can’t experiment with XIAO, as it expects 5V in its Vin, and then 3.3V are hard-wired to VDD and VDDH, according to this:
The DK is ordered, so, hopefully, I’ll be able to experiment with this soon.
As I has also ordered a Dongle, based on the description, this feature is also available there, so I can right away test it in my project in a size-friendly way. @PJ_Glasso , thanks a lot for pushing me onto this territory!
Is it something which can be selected via the nrf Desktop application?
P.S. I was able to find an answer to my stupid question about skipping any buck/boost converters and recklessly supplying a ranged voltage over the period of the battery life directly to the nrf52840, namely: whatever the battery gives out until it hits as low as 1.7V.
Minimum voltage drop in REG0 (difference between voltage supplied on VDDH pin and voltage output on VDD pin) - 0.3V