Fixed 2.9V rail for precision analog and sensor bias
The LP2980AIM5X-2.9/NOPB is a positive fixed 2.9 V output LDO regulator with a single 50 mA output. The 2.9 V fixed output and 63 dB PSRR at 1 kHz suit noise-sensitive loads.
Dropout and quiescent current — sizing the headroom budget
Maximum dropout is 0.22 V at the full 50 mA load. For a 2.9 V output, the input must stay above 3.12 V worst-case — a 3.3 V rail with 5 % tolerance (3.135 V min) barely clears it. In battery applications, the dropout figure sets the end-of-discharge voltage: a Li-ion cell at 3.0 V is too low; a 3.6 V or 5 V rail provides comfortable margin.
No official successor or pin-compatible second source is recorded in the lifecycle data — each replacement candidate must be validated for output voltage, dropout, and enable logic.
Built-in protection includes over-current, over-temperature, and short-circuit shutdown. The Enable control feature allows the regulator to be shut down by a logic signal, reducing quiescent current to near zero when the load is idle — useful for power-gated sensor nodes or intermittent-duty RF transceivers.