nRF52 at 1.8V - DCDC efficiency?

[samsonc]

Hi, Is there any information on how much improvement the DCDC has over the LDO at 1.8V? I'm working on a heavily space-constrained application, and I'm trying to make a decision as to whether or not it's worthwhile to use the board space for the inductors.

Thanks!

[RK]

The product spec has run currents at 3V supply with LDO and DCDC, that should tell you pretty much everything you need to know. Roughly, the the nrf52836, the DCDC currents are around 50%, so even adding a margin of error, that's 50% or more extra battery life.

[samsonc]

Unless I'm misunderstanding, I'm specifically asking about the system with a 1.8V rail. My system has no 3V rail. As I understand it, most of the logic and RF on chip runs at ~1V internally, but still requires an internal LDO before the buck converter, so I don't know the actual percent loss with LDO vs. DC-DC at 1.8V, where the improvement is far more marginal. Given the min operating voltage is 1.7V, I'm suspecting the improvement with a switcher is rather marginal from 1.8V, especially accounting for typical efficiencies of decent buck converters (85%ish?).