The MIC2951-03YN is a positive-output linear regulator from Microchip Technology, delivering up to 150 mA from a 30V maximum input rail. The output is adjustable from 1.24V up to 29V, with a fixed 5V option selected by the internal resistor divider — one part number covers two rail voltages depending on the feedback pin connection. The tube packaging means it ships in anti-static tubes, not tape-and-reel — store it in the tube or transfer to a conductive foam strip; the leads are tin-plated and solder readily with a standard iron.
Key ratings and what they mean for the BOM
150 mA output current is a local rail regulator — it powers an op-amp supply, a sensor bias, or a microcontroller's analog section, not a whole board. The 0.6V dropout at full load means the input must stay at least 200 mV above the output voltage to maintain regulation; a 5V output needs a 5.2V minimum input, which a standard 5V rail cannot deliver unless it is post-regulated from a higher voltage. This regulator sits in an engine-bay ECU, an outdoor telecom enclosure, or a factory-floor sensor head without derating the output current at high ambient — the 150 mA rating holds across the band. Quiescent current is 300 µA typical — not a micropower part, but low enough for always-on industrial rails where the load current dwarfs the Iq. The 8 mA maximum supply current is the worst-case figure when the regulator is not in dropout; it is not a concern for a 150 mA rail. Built-in protection covers over-current, over-temperature, and reverse polarity on the input. The reverse-polarity clamp means an accidental battery reversal does not blow the regulator — the internal diode conducts and limits the reverse voltage to about 0.7V, saving the downstream load.