PSRR and noise rejection across the audio band
The MCP1791-3002E/ET delivers 90 dB PSRR at 100 Hz, tapering to 80 dB at 1 kHz — this is the range where switching regulator ripple and 50/60 Hz mains hum sit. For an analog front-end or sensor bias rail, that rejection means the LDO cleans up the supply before the downstream amplifier sees it.
Dropout and quiescent current for always-on rails
Maximum dropout is 1.3 V at the full 70 mA load — the input rail needs at least 4.3 V to hold 3 V regulation at full current. Quiescent current is 130 µA typical, with a maximum supply current of 210 µA, so the regulator's own draw stays low enough for battery-backed memory or microcontroller keep-alive rails.
Industrial temperature range and protection
On-chip over-temperature and short-circuit protection keep the output from failing into a hard fault.