3V fixed LDO with 80 dB PSRR — what that means for your analog rail
The BH30NB1WHFV-TR is a 150 mA positive-output linear regulator from ROHM, delivering a fixed 3 V from a maximum 5.5 V input. The 80 dB PSRR at 1 kHz is the standout spec here — it attenuates switching ripple from a buck converter by a factor of 10,000, so a 10 mVpp ripple on the input rail becomes roughly 1 µVpp at the output. That matters when you're feeding a 16-bit ADC reference or a low-noise op-amp front-end. Quiescent current is 100 µA — not a micropower part, but acceptable for always-on analog sections where the load current dominates the power budget.
Package and board-fit — SOT-665 / 5-HVSOF
The exposed pad on the bottom side is the thermal path — the datasheet's RthJA assumes a copper land on the PCB under the pad. The Enable pin lets you shut down the output to near-zero quiescent current when the rail is not needed — useful for sequencing or power-saving modes. Protection features include over-current and over-temperature shutdown, so a shorted load on the output won't kill the regulator permanently.
Lifecycle and compliance — active, ROHS3, no obsolescence watch needed
The tape-and-reel packaging (TR suffix) is standard for SOT-665 reels; cut-tape samples are also available for prototyping. Store the reels dry — the MSL level for this package is typically MSL 1 or 2, but confirm the reel label before assuming no bake needed.