3 A buck — the workhorse rating
The LM2596T-ADJ/NOPB: Rated for 3 A continuous output, this is a single-output positive buck regulator from the SIMPLE SWITCHER® family. The 150 kHz switching frequency is on the low side by modern standards, which means the inductor will be physically larger than what a 500 kHz part needs, but the trade-off is simpler layout and lower switching losses in the diode and pass transistor.
Input and output voltage envelope
Input range runs from 4.5 V up to 40 V, and the adjustable output can be set anywhere from 1.2 V to 37 V via a resistor divider. No synchronous rectifier on board — the external Schottky diode handles the catch current, which is a standard bill-of-materials item.
TO-220-5 — field-swappable package
Housed in a TO-220-5 with formed leads, this is a through-hole part you can swap on site with a soldering iron and a basic desoldering tool. The tab is the output connection and also the main thermal path — bolt it to a heatsink if the load stays above 2 A continuously.