Fixed 3.3V boost from a single cell
The Texas Instruments TPS613221ADBVR is a step-up (boost) DC-DC converter that delivers a fixed 3.3V output from an input as low as 0.9V. That means it can keep a 3.3V rail alive from a single alkaline cell that's nearly dead — handy for portable gear where you want every last drop of battery life. The 1.6A switch rating gives you headroom for loads up to around 400-500 mA continuous, depending on input voltage and inductor choice.
SOT-23-5 footprint and thermal reality
The TPS613221ADBVR comes in a SOT-23-5 package. That's a five-pin part with a small footprint — good for tight layouts, but the thermal dissipation is limited. The switching frequency range of 500 kHz to 2 MHz lets you trade off inductor size against efficiency — 1 MHz is a common sweet spot for a compact design.
Active production, no LTB worry
For a BOM line, this is a straightforward sourcing decision — no last-time-buy math, no broker scavenger hunt.