ADP5360 Power management IC confusing pin description

Thread Starter


Joined Mar 15, 2023
Hello Everyone,
I've been studying the Nordic Semiconductor's Thingy 91 schematic files and I can't wrap my mind around the ADP5360 PMIC used for battery management. The pin description is confusing. What pin is actually powering the IC? The VBUS pin or the VDD pin? and what exactly is the purpose of VSYS here. What happens when there is no external power source available and the device has to rely on battery for its power, the IC is being powered from VBUS then how does it work when there's no external power because I see no connection between VBUS and the battery. My main question is how does the battery monitoring work when there's no external power?