The LM1117MPX-ADJ/NOPB adjustable LDO sets its output via an external resistor divider from a 1.25 V reference up to 13.8 V, with a 15 V input ceiling. The 1.2 V maximum dropout at 800 mA requires the input to stay at least that margin above the target output.
75 dB PSRR — ripple rejection for noise-sensitive rails
That 75 dB of ripple attenuation at line frequency (120 Hz) knocks a 1 Vpp ripple down to roughly 0.18 mVpp at the output — clean enough to feed an analog front-end or a precision reference without a second-stage filter. The PSRR rolls off at higher frequencies, so for switching-regulator post-filtering, add a ferrite bead or a small RC at the input.
Protection features and quiescent current
On-chip over-current and over-temperature protection are included — the part folds back current and shuts down if the junction exceeds the thermal limit, then auto-recovers. That Iq is higher than modern CMOS LDOs, but acceptable for post-regulated rails where the load current dominates the power budget.
Supplied in the SOT-223 surface-mount package, the LM1117MPX-ADJ/NOPB is rated for operation from 0°C to 125°C — the commercial-plus temperature range covers most indoor and industrial equipment that does not see extreme cold.