Automotive LDO with AEC-Q100 qualification
The BU18JA2MNVX-CTL from ROHM Semiconductor is a single-output, fixed 1.8V LDO regulator rated for 200 mA continuous output. It is qualified to AEC-Q100, the automotive IC stress test standard, and operates across -40°C to 125°C — covering the under-hood and cabin temperature envelope without derating.
Key parametrics for the BOM
A PSRR of 70 dB at 1 kHz means the LDO attenuates switching ripple from upstream converters by a factor of over 3000 — useful for powering sensitive analog front-ends or RF circuits in an automotive ECU where the 12V rail carries alternator whine. Quiescent current is 90 µA typical, which keeps the regulator's own draw low enough for always-on modules like a CAN transceiver or body controller that sit on the battery even when the ignition is off. For a 3.3 V supply feeding this LDO, the headroom is roughly 0.8 V, which is adequate across line and temperature. Input voltage range extends to 6 V max, so the part tolerates 5 V ±10% rails directly without an intermediate regulator. The 1.8 V fixed output is the nominal voltage for many low-power MCU cores, DDR termination, or sensor bias lines. Integrated over-current and over-temperature protection shut down the pass transistor under fault conditions — the LDO recovers automatically when the fault clears, so no external crowbar or latch-up recovery circuit is needed.
The 4-UDFN exposed pad package (SSON004R1010) mounts on a surface-mount board. ON/OFF control pin is available for sequencing — pulling it low disables the output and drops the quiescent current to near zero, which is useful for power-rail sequencing in multi-rail automotive modules.
ROHS3 compliance is confirmed on the manufacturer's documentation, covering the substance restrictions for automotive programs that require IATF 16949 material declarations.