2.25 MHz switching — what it buys the layout
The TPS62273DRVR is a step-down buck regulator from Texas Instruments, switching at 2.25 MHz. That frequency lets you use smaller inductors and capacitors than a 500 kHz part would, which shrinks the board footprint. The trade-off is that the fast edges couple more easily into adjacent traces, so keep the switching node short and the feedback path away from the inductor.
400 mA output — load budget and derating
Rated for 400 mA continuous output, this part handles low-power rails like a 3.3 V MCU supply or a 2.5 V sensor rail. The input range of 2 V to 6 V covers single-cell Li-Ion and 3.3 V / 5 V regulated buses. The synchronous rectifier keeps efficiency up at light loads, which matters for battery-powered gear.
6-WSON (2x2) — package and thermal reality
The 6-WSON package measures 2 mm x 2 mm with an exposed pad.