1.5 A adjustable LDO — 40 V input ceiling, TO-220-3
The LT317AT#PBF is a positive adjustable linear regulator delivering up to 1.5 A from a 40 V maximum input rail, with the output set anywhere from 1.25 V up to 40 V via two external resistors. Housed in a TO-220-3 through-hole package, it mounts into a standard TO-220 footprint on the board — the tab is the output pin, so the heatsink pad connects to the load, not ground.
PSRR 80 dB to 65 dB at 120 Hz — ripple rejection across the line-frequency band
Power-supply rejection ratio is specified at 80 dB typical at 120 Hz, rolling off to 65 dB at the same frequency — this covers the full-wave-rectified ripple from a 60 Hz mains input, meaning the regulator attenuates the 120 Hz hum by a factor of 10,000 at the low end. For a 1 Vpp ripple on the input rail, the output sees roughly 100 µVpp at 120 Hz — clean enough to feed an analog front-end without additional post-filtering.
Over-temperature protection — the only built-in safeguard
The sole protection feature listed is over-temperature shutdown — the die shuts the pass element off when the junction exceeds the thermal limit, then re-enables after cooling. There is no built-in current limit or reverse-polarity protection, so the external circuit should handle those conditions if the application demands them.