The LM78L15ACMX/NOPB is a positive fixed 15V linear regulator from Texas Instruments, delivering up to 100mA from a maximum input voltage of 35V. The 51dB PSRR at 120Hz means ripple from a full-wave rectified or switching supply is attenuated by a factor of ~350 — a 100mVpp input ripple drops to under 0.3mVpp at the output, which is sufficient for precision op-amp rails and 12-bit ADC references. Quiescent current is 3mA typical, so the regulator's own draw is a fixed overhead on the input rail regardless of load — relevant for battery-powered designs where the 100mA output is the ceiling, not the idle current.
Package, mounting, and protection
On-chip protection includes over-temperature shutdown and short-circuit current limiting — the regulator folds back safely under a sustained output short without external clamp diodes. Operating temperature spans 0°C to 125°C, covering commercial and most industrial ambient ranges; the 0°C lower bound means it is not rated for cold-start automotive or outdoor telecom enclosures below freezing.