3V fixed LDO in a 1.0×1.0 mm package
The ROHM BU30TD2WNVX-TL is a single-output positive fixed LDO regulator delivering 200 mA at 3 V from a maximum 6 V input rail. The 60 µA quiescent current keeps the self-consumption low in always-on or battery-backed rails, while the 0.46 V max dropout at full load means the input needs only 3.46 V to hold regulation — useful when the front-end rail sags under transient load. The Enable pin lets a system controller gate the output rail, pulling the regulator into a low-power state when the downstream load is idle. Over-current and over-temperature protection are built in — the part folds back or shuts down rather than letting the junction run past the safe operating area.
70 dB PSRR — what it buys the analog rail
For a 100 mVpp switching ripple from a buck converter feeding the LDO, the output sees roughly 32 µVpp — clean enough to bias a 16-bit ADC reference or a sensitive analog front-end without additional post-filtering. PSRR rolls off with frequency; the 1 kHz figure is the mid-band sweet spot. Above a few hundred kHz the rejection drops, so the upstream switching frequency and the LDO's own bandwidth determine whether the output ripple stays within the load's supply-rejection budget.
The 4-UDFN exposed pad package with the SSON004X1010 supplier designation measures 1.0 × 1.0 mm — a footprint that fits into space-constrained wearable, sensor-module, or IoT-endpoint designs. Surface-mount assembly with tape-and-reel or cut-tape packaging suits both prototyping and volume pick-and-place.
ROHS3 compliance covers the EU RoHS exemption list, so the part fits into products destined for European markets without a substance-restriction waiver.