12 V fixed rail, 100 mA capacity, TO-92-3
The ST L78L12ABZ-AP is a positive fixed linear regulator delivering a 12 V output at up to 100 mA. It comes in the TO-92-3 through-hole package with formed leads, a staple for low-power board-level regulation. Input voltage tolerance goes to 35 V max, giving enough headroom for unregulated supplies or multi-rail designs without a pre-regulator.
PSRR and quiescent draw
Power supply rejection ratio is 42 dB at 120 Hz — this is the ripple attenuation the regulator provides from the input to the output at full-wave rectifier frequency. For a 1 Vpp ripple on the input, the output sees roughly 8 mVpp, which keeps downstream analog or logic rails clean enough for most mixed-signal boards. Quiescent current is 6 mA typical (6.5 mA max supply current), so the regulator's own draw is a small fraction of the 100 mA output budget — relevant for always-on circuits where every milliamp counts.
Protection and temperature range
Built-in protection covers over-current, over-temperature, and short-circuit conditions — the regulator survives an output short indefinitely without external clamp diodes in most applications. Operating temperature spans -40°C to 125°C, making it suitable for industrial enclosures and automotive-adjacent environments where the ambient sees wide swings.
Active lifecycle, RoHS3 compliance
Product status is Active per the manufacturer, with RoHS3 compliance confirmed. Available in Tape & Box (TB) or Cut Tape (CT) packaging, the TO-92-3 body fits standard 0.1-inch pitch prototyping boards and production through-hole layouts alike.