The Texas Instruments TPS62161DSGT is a synchronous step-down (buck) regulator that delivers a fixed 1.8V output at up to 1A from a 3V to 17V input rail. It uses TI's DCS-Control topology.
1A output — sizing the load budget
The 1A continuous output current is the hard ceiling for the load. The synchronous rectifier helps efficiency at light loads.
Input range and output voltage — what the numbers mean
The 3V minimum input and 17V maximum cover a range of supply rails. The output is fixed at 1.8V.
Surface-mount assembly is standard.
For dual-sourcing resilience, the LM53625LQURNLRQ1 is a functional peer — same buck topology, 2.1 MHz switching, 2.5 A output, but automotive-qualified (AEC-Q100) and in a wettable-flank package. It is not a pin-for-pin drop-in, but a valid alternative for a second-source qualification effort.