Fixed 4.5 V rail with 120 mA headroom
The MAX8510EXK45: The dropout voltage is 0.12 V typical at full load, so a 4.62 V input rail keeps the output in regulation across the load range. Power-supply rejection ratio (PSRR) runs 78 dB at 1 kHz, rolling off to 54 dB at 100 kHz — that 24 dB of attenuation above 10 kHz means the LDO cleans up switching ripple from a preceding buck converter well enough for an analog front-end that cannot tolerate feedthrough. Quiescent current is 90 µA typical, low enough for battery-powered equipment that spends most of its time in a light-load state, though the 120 mA ceiling keeps it in the low-current regulator class rather than a general-purpose rail.
Protection and temperature range
On-chip over-current and over-temperature protection cover the LDO against a hard short or a stalled load — the thermal-shutdown threshold sits above the 85°C ambient limit, so the part cycles into and out of protection rather than failing open. A shutdown pin (active-low logic) lets a microcontroller or supervisor pull the output to zero and cut the rail.
The MAX8510EXK45 comes in an SC-70-5 (SOT-353) surface-mount package with a 1.25 mm pitch — a two-layer board can route the input, output, ground, and shutdown traces without a via under the part. The bulk packaging means it ships in tubes or trays rather than tape-and-reel, so a pick-and-place line needs to handle the non-reel format.