3 A / 2 A triple buck — what the current rating buys the design
The TPS65251RHAR from Texas Instruments is a triple-output step-down (buck) regulator that delivers 3 A on one channel and 2 A on the other two, all from a single 4.5 V to 18 V input rail. The adjustable output down to 0.8 V lets it power a mix of core, I/O, and auxiliary rails in a single-chip power tree.
Switching frequency range — inductor sizing and ripple trade-off
The 300 kHz to 2.2 MHz switching frequency range gives the designer room to choose: lower frequencies improve efficiency at the cost of larger inductors and higher output ripple; higher frequencies shrink the magnetics but increase switching losses. Synchronous rectification keeps the efficiency penalty manageable across the band.