2.8V fixed LDO with 150mA output and low dropout
The LP3999ITLX-2.8/NOPB from Texas Instruments is a fixed-output low-dropout linear regulator delivering 2.8 V at up to 150 mA. Its maximum dropout voltage of 0.1 V at full load means the input rail can sit as low as 2.9 V and still maintain regulation — useful in battery-powered designs where every millivolt of headroom matters. Power-supply rejection ratio (PSRR) is 60 dB at 1 kHz, rolling off to 50 dB at 10 kHz. That's enough attenuation to clean up ripple from a switching pre-regulator before it reaches sensitive analog loads like an ADC reference or audio codec.
Package, footprint, and hand-soldering reality
The part comes in a 5-bump DSBGA (Wafer-Level Chip Scale Package) measuring 1.41 x 1.08 mm — roughly the size of a grain of rice. The 0.5 mm pitch and lack of exposed side leads mean it's not a breadboard-friendly part; you'll need a PCB with matching land pattern and a reflow oven or hot-air station. Cut tape and reel options are available for prototyping quantities. Enable pin (active high) lets you shut down the output and drop quiescent current to near zero — handy for battery-powered devices that sleep most of the time. Over-temperature and short-circuit protection are built in, so a momentary output short won't kill the regulator.
ROHS3 compliant, so it meets current EU and global environmental requirements without exemption.