Hi,
I have used PPK2 to measure nRF9160 current using different boards. I like the product, but I'd like to note is that there seems to be a typo in the PPK2 documentation. The "Quick start" page for nRF9160DK instructs to connect: PPK2 VOUT to P24 VDD_nRF' / PPK2 VIN to P24 VDD_nRF, while "Measuring current in Ampere Meter mode" page has VOUT and VIN the other way around. The pin connections on the "Quick start" don't work.
I have also a question about the source mode. I've used the "Source mode" measurement with Thingy91 and Circuitdojo nRF9160 Feather boards. In the measurements the PPK2 is connected to the battery connector of the board. I have also tested connecting 100uF + 10uF capacitors parallel with the PPK2 to the battery connector. With the Feather board the external capacitors have a significant impact on the avg current.
Is the PPK2 source to a battery connector accurate measurement method or would ampere meter mode with a real battery be more accurate?
I've attached pictures of the measurements. nRF9160 Feather with/without external capacitors and Thingy91 (v1.4.0) with/without external capacitors. The FW in the measurements is application idle & modem PSM.
Thingy91 + external capacitors:
Thingy91 without external capacitors:
Feather + external capacitors:
Feather without external capacitors:
Br,
Ilkka
