Fixed 5 V LDO for noise-sensitive 50 mA rails
The LP2980IM5X-5.0/NOPB: Key protection features include over-current, over-temperature, and short-circuit, and an enable pin gives the designer a shutdown path for power sequencing.
Dropout and PSRR — the deciding specs for a 5 V rail
Dropout voltage is 0.22 V max at 50 mA output — that means the input rail can sag to 5.22 V before the output drops out of regulation. For a 5 V rail fed from a 5.5 V or 6 V bus, that headroom is tight; you need a clean input above 5.22 V to hold regulation. PSRR is 63 dB at 1 kHz, which attenuates 1 mV of input ripple to roughly 0.7 µV at the output. That matters when this LDO feeds a noise-sensitive load like an ADC reference or an audio codec.
Quiescent current and supply budget
At 50 mA load, the efficiency is dominated by the dropout voltage, not the Iq — but in a standby or always-on rail, the 95 µA Iq keeps the battery drain low.