4-DSBGA footprint and the PSRR story
The LP5904TME-3.1/NOPB: The fixed 3.1 V output at 200 mA is enough for a sensor or MCU analog rail, but the dropout is 150 mV max at full load, meaning the input must stay above 3.25 V to hold regulation. What sets this part apart is the PSRR curve: 88 dB at 100 Hz, dropping to 30 dB at 2 MHz. That 88 dB at line frequency means it rejects 60/120 Hz ripple from a rectified supply almost completely — useful when the LDO follows a switching pre-regulator. The roll-off above 100 kHz is typical for a low-Iq LDO; the 50 µA quiescent current keeps the battery draw low in always-on applications, but the trade-off is less rejection of switching noise above 1 MHz. Enable pin lets the system power down the rail — the 230 µA max supply current when enabled drops to near zero when the pin is pulled low. Over-temperature and short-circuit protection are built in, so the regulator survives a momentary output short without latching off.
ROHS3 compliant per, so it clears European and domestic RoHS requirements without an exemption.