Dual-rail power from a single cell
The TPS61107PWG4 combines a synchronous boost converter delivering 3.3V at 1.8A with a linear LDO output of 1.8V at 500mA — both from an input supply as low as 0.8V. That input floor means it can keep running off a single alkaline or Li-ion cell well into its discharge curve, something a conventional boost that cuts out at 2.5V cannot do. The 500kHz switching frequency keeps the inductor small enough for space-constrained portable gear.
Output rails and loading
Output 1 is a fixed 3.3V rail rated for 1.8A — sized to power a 3.3V MCU plus peripheral loads without a separate post-regulator. Output 2 is a 1.8V LDO at 500mA, typically used for a low-voltage core or I/O bank. The two outputs share the same input, so the total load current drawn from the battery is the sum of both rails divided by the boost efficiency; at 500kHz the switching losses are modest, but the inductor saturation current must cover the peak of the boost stage plus the LDO's draw.