Wide-VIN buck for 12/24/48 V industrial rails
The LMR36506R5RPER is a 600 mA synchronous step-down regulator from TI's SIMPLE SWITCHER family, accepting 3 V to 65 V input and delivering a fixed 5 V output. That 65 V ceiling covers 48 V nominal telecom supplies with margin for transients, and the 3 V minimum lets it start from a deeply-discharged 12 V battery or a 5 V pre-regulated rail. The 600 mA continuous output suits sensor modules, I/O isolators, and auxiliary housekeeping rails in motor drives or PLC racks where the main load is a few hundred milliamps. The synchronous rectifier keeps efficiency above 90 % down to light loads, which matters when the converter idles between burst reads from a fieldbus transceiver.
Switching frequency and thermal envelope
At the low end you minimise switching losses for a 48 V input; at the high end you shrink the inductor to 2.2 µH or 3.3 µH, which fits the 2×2 mm package profile. The 150 °C junction temperature rating gives headroom in a sealed enclosure with 85 °C ambient and no forced air — the thermal pad under the 9-VQFN-HR carries the heat into the PCB copper pour. The fixed 5 V output eliminates the feedback divider and the associated noise injection on the sense node — one less component to place in the tight layout around the 2 mm QFN.
The 9-VQFN-HR (2×2 mm) package with wettable flanks supports automated optical inspection (AOI) of the solder joints — no hidden fillets under the body. The exposed thermal pad is on the bottom; the recommended PCB land pattern includes a 2.2×2.2 mm thermal pad with at least four vias to the inner ground plane. Available in Tape & Reel (TR) and Cut Tape (CT) options for prototype or production quantities.