Fixed 2.5V LDO with 150mA output
The Texas Instruments LP5951MF-2.5/NOPB is a fixed-output linear regulator delivering 2.5V at up to 150mA from a maximum input of 5.5V. Maximum dropout is 0.35V at full load, so a 2.85V input rail leaves enough headroom for regulation across temperature and load steps.
PSRR and noise rejection across frequency
PSRR measures 60dB at 100Hz, rolling off to 50dB at 10kHz — the regulator attenuates low-frequency ripple from a switching pre-regulator or AC line hum by a factor of 1000 at the lower end. Above 10kHz the rejection continues to drop; for sensitive analog front-ends, a post-filter cap at the output helps maintain clean rails at switching frequencies above 100kHz.
Quiescent current and enable for battery duty
The Enable pin lets a system controller shut down the output completely, dropping the load to near-zero when the rail is not needed.
Temperature grade and protection
Built-in over-current, over-temperature, and short-circuit protection allow the regulator to survive output faults without external clamp diodes.
Supplied in SC-74A / SOT-753 (SOT-23-5) surface-mount package, the footprint is standard for 5-pin SOT-23 with 0.95mm pitch — no special layout beyond a 1µF ceramic input cap and 1µF output cap placed close to the pins.