Regulator core — what the 2.5 MHz buys you
The TPS62143RGTR is a synchronous step-down (buck) converter from TI's DCS-Control family, delivering a fixed 5 V output at up to 2 A from a 3 V to 17 V input rail. The 2.5 MHz switching frequency lets you use a smaller inductor and output capacitor than a 500 kHz part — the trade-off is slightly higher switching losses, but for a 2 A rail the efficiency curve peaks well above 90 % across most of the load range.
Input range and output — what it powers
The 3 V minimum input covers a single Li-ion cell (3.0–4.2 V) and a 5 V rail with margin; the 17 V maximum handles 12 V industrial buses and multi-cell battery packs. The fixed 5 V output saves a feedback resistor pair and one capacitor, which matters when board space is tight.