Two rails from a single cell – the boost+LDO combo
The TPS61098DSER packs a synchronous boost converter delivering 4.3 V at 350 mA and a separate LDO output at 2.2 V / 200 mA into one 6-WSON package. That second regulated rail saves you an external LDO and its associated passives when you need a clean 2.2 V supply for an analog front-end or a low-voltage logic rail.
Input range that squeezes the last drop out of a battery
The 0.7 V minimum supply voltage means this part can start up and regulate from a single alkaline cell that has dropped below 1 V – the boost stage keeps the 4.3 V rail alive while the cell discharges down to 0.7 V. The 4.5 V maximum input covers two-series alkaline or a single Li-ion with headroom.