What this part does in a handheld build
The Texas Instruments TPS61120RSAR is a power management IC built for battery-powered handheld and mobile devices. Quiescent current sits at 10 µA — low enough that the part can stay alive in a always-on sense block without draining the battery between charge cycles.
Temperature range and field environment
The 16-VQFN with exposed pad (4x4 mm body) keeps the footprint small, but the pad needs a solid thermal via pattern to the ground plane if the load draws more than a few hundred milliamps continuously.