2.5V fixed rail, 500 mA, and the thermal pad story
The TPS73525DRVR is a single-output positive LDO from Texas Instruments, fixed at 2.5 V, rated for 500 mA continuous output. The dropout voltage maxes out at 0.5 V at full load — so the input rail needs to sit at least 3.0 V to keep the output in regulation when you pull the full 500 mA. It comes in a 6-WDFN exposed pad package (6-WSON, 2x2 mm). Quiescent current is 65 µA typical — low enough for battery-powered gear that spends most of its time in a light load state. The Enable pin lets you shut the output off entirely when the rail is not needed.
PSRR roll-off — what it means for the noise budget
Power supply rejection ratio (PSRR) is 66 dB at 100 Hz, dropping to 22 dB at 100 kHz. That means the regulator does a good job cleaning up 100/120 Hz ripple from a rectified AC source, but above 1 kHz the rejection falls off fast. If your upstream supply is a switching converter running at 500 kHz or higher, most of that switching noise passes straight through to the 2.5 V rail unless you add a post-filter LC stage. The protection set includes over-current, over-temperature, reverse polarity, and under-voltage lockout (UVLO). The reverse polarity protection is a nice field-safety feature — if someone clips the input backwards during a bench swap, the regulator does not let the smoke out. UVLO holds the output off until the input rail is stable above the threshold, which prevents glitched power-on sequences on a marginal supply.