Automotive-grade 3.3V rail: the BD33HA3MEFJ-ME2
The ROHM BD33HA3MEFJ-ME2 is a single-output, positive-voltage, fixed 3.3 V LDO regulator rated for 300 mA continuous output. The device integrates over-current, over-temperature, and soft-start protection, reducing external monitoring circuitry. Enable control is provided on-chip, allowing the regulator to be gated by a system supervisor or ignition signal.
Dropout margin at full load
Maximum dropout is specified at 1.2 V with the full 300 mA load. That means a 4.5 V pre-regulator rail (or a battery bus during cold-crank) still holds the 3.3 V output within regulation. For designs running near the 8 V input maximum, the dropout is effectively irrelevant, but the margin matters in start-stop automotive profiles where the supply dips below 5 V.
The device is housed in an 8-SOIC (3.90 mm width) with an exposed pad (8-HTSOP-J).
ROHS3 compliant. The series is flagged as Automotive, AEC-Q100, so the part is released under automotive change-notification and PPAP requirements.