3V rail for a 150mA load — the dropout tells you the headroom
The MAX8877EUK30+T is a single-output positive LDO from Analog Devices, delivering a fixed 3V output at up to 150mA. The typical dropout voltage is 165mV at full load — so the input rail needs to stay above 3.165V to keep the output in regulation. Below that, the output follows the input minus the dropout, and the PSRR collapses. In a battery-powered design where this LDO is always on, that standing current is the floor of the system power budget — it matters more than the dropout if the load is intermittent.
Protection set that saves external parts
The MAX8877EUK30+T integrates over-current, over-temperature, reverse polarity, and short-circuit protection. That means you don't need a separate eFuse or Schottky diode on the input for reverse-battery protection in single-supply designs — the LDO handles it internally. The thermal shutdown threshold is set above the 85°C ambient limit, so an output short pulls current until the die hits the trip point, then cycles. The enable pin lets a GPIO or supervisor pull the output to zero and drop the quiescent current to near-zero — useful for sequencing multiple rails or for a sleep state where the 3V bus is powered down entirely.
The part comes in an SC-74A / SOT-753 package, which is the standard SOT-23-5 footprint. The 5-pin layout has the input on pin 1, ground on pin 2, enable on pin 3, output on pin 4, and the die attach paddle on the bottom — that paddle is the thermal path, so a via under the package to the ground plane helps keep the junction temperature down at 150mA.
If the design needs the wider -40°C to +125°C automotive grade, this part is not the fit — the MAX8877 family does not carry an AEC-Q100 variant.