PSRR — the spec that decides fit for sensitive rails
Rated 80 dB PSRR at 100 Hz, rolling off to 60 dB at 100 kHz. That 80 dB figure at line-frequency ripple means the regulator attenuates 100/120 Hz rectifier hum by a factor of 10,000 — relevant when this LDO follows a switching preregulator or powers an analog front-end where power-supply rejection at the ADC reference matters. The 60 dB floor at 100 kHz still knocks down switching-regulator ripple by 1,000:1. Compare this to the STLQ020C33R peer, which lists 52 dB to 45 dB over 100 Hz to 10 kHz — the LDLN025PU25R holds roughly 28 dB more rejection at line frequency and maintains useful attenuation an order of magnitude higher in frequency.
Dropout, quiescent current, and the 2.5 V rail
Maximum dropout is 0.25 V at the full 250 mA output. The 25 µA quiescent current (Iq) makes this a candidate for always-on rails in battery-powered designs where the regulator's own draw matters more than the load's sleep current. Output is fixed at 2.5 V, positive configuration, single regulator.
Protection set and temperature grade
Over-current, over-temperature, short-circuit, and soft-start protection are all integrated — no external watchdog or current-limit resistor needed.
Package reality — 1x1 mm DFN
The 4-XDFN exposed pad package measures 1x1 mm (supplier device package 4-DFN). Surface-mount only; no through-hole variant exists.