Fixed 3.3 V at 1 A — the ratings that decide BOM fit
The TL2575-33IKV: This is a fixed-output 3.3 V buck regulator delivering 1 A continuous. No adjustable version — the output voltage is set internally, so the BOM needs no feedback divider. The 52 kHz switching frequency is low by today's standards; it keeps the inductor physically larger than a 500 kHz design but reduces switching losses and radiated EMI. The 4.75 V to 40 V input range lets it regulate from a loosely regulated 5 V rail or a 24 V industrial bus without a pre-regulator.
Through-hole TO-220-5 — board fit and thermal path
The TO-220-5 package is a through-hole power package with a metal tab for heatsinking. The tab is the ground path and the primary thermal interface — a PCB copper pour under the tab or a bolt-on heatsink keeps the junction below 125°C at 1 A output. No synchronous rectifier means an external Schottky diode carries the catch current; pick one rated for the input voltage and 1 A average with margin.
This covers industrial enclosures, outdoor telecom cabinets, and under-hood automotive-adjacent environments. The 125°C ceiling is the junction limit, not the ambient — derate the 1 A output according to the thermal resistance of the TO-220 tab-to-ambient path.