Dual-rail power for 5V and 12V intermediate buses
The TPS65252RHDT from Texas Instruments is a dual-output synchronous buck regulator that delivers 3 A on one channel and 2 A on the other, both adjustable from 0.8 V up to 15 V. It takes a 4.5 V to 16 V input, covering the common 5 V and 12 V intermediate bus rails used in industrial control, telecom line cards, and networking equipment. The two outputs can be sequenced independently, which matters when a processor core must power up before its I/O rail.
Switching frequency — inductor size vs efficiency trade
At the low end, efficiency peaks but the inductor footprint grows; at the high end, the inductor shrinks to a 2.2 µH or 1 µH part, which helps on a dense 28-VFQFN layout. The synchronous rectifier keeps the efficiency curve flat across load — expect 85-90% range depending on the frequency and duty cycle chosen.
Package and thermal — the exposed pad is your heat path
The 3 A channel will need airflow or a copper pour area of at least 1 in² on the inner layer to keep junction temperature below the 125°C limit at full load.
Lifecycle — no obsolescence watch needed
The base product number TPS65252 covers a family of dual-output regulators; the RHDT suffix denotes the 28-VFQFN package and Tape & Reel shipping format.