15 V fixed rail, 1 A continuous — the dropout margin matters
The LM2940CSX-15/NOPB is a positive fixed-output LDO from Texas Instruments delivering a regulated 15 V at up to 1 A. The output is fixed at 15 V with no external resistor divider needed — it is a drop-in rail for post-regulator or point-of-load stages that need a clean 15 V supply from a higher unregulated bus. Maximum dropout is 0.8 V at the full 1 A load, so the input rail needs at least 15.8 V to maintain regulation. That 0.8 V headroom is tight for a 12 V bus — this part is designed for input rails from 15.8 V up to 26 V, not for 12 V-to-15 V conversion.
Protection set reduces external clamp circuitry
On-chip protection includes over-current, over-temperature, reverse polarity, and short-circuit. The reverse polarity protection is a practical feature for automotive or battery-backed rails where a reversed input connection can happen — it saves a series Schottky diode and its voltage drop.
TO-263-3 package — thermal pad and board layout
The package is a TO-263-3 (DDPAK) with an exposed tab on the back side.