Fixed 5 V rail for noise-sensitive loads
The LP2980IBP-5.0/NOPB is a single-output positive LDO regulator from Texas Instruments that delivers a fixed 5.0 V output at up to 50 mA. Its PSRR of 63 dB at 1 kHz makes it a candidate for powering analog blocks — ADC references, op-amp rails, or sensor front-ends — where a switching regulator would inject ripple into the signal path.
Dropout and quiescent current — the headroom trade-off
Maximum dropout is 0.22 V at the full 50 mA load, so a 5.0 V rail needs an input above about 5.22 V to stay in regulation. Quiescent current is 95 µA typical, rising to 1.2 mA max under all conditions — low enough for always-on domains in battery-powered gear, though not the ultra-low-Iq tier for coin-cell designs.
For a production BOM, the realistic path is sourcing remaining factory inventory or verified surplus through independent distribution.
5-µSMD — board area vs. assembly care
The 5-µSMD package measures 0.93x1.11 mm — roughly the size of a grain of pepper. It saves real estate on a dense mixed-signal board, but the fine-pitch bumps demand a controlled reflow profile and post-assembly X-ray inspection. The Enable pin (active-high) lets a system supervisor gate the output during power sequencing or sleep modes.