AEC-Q100 LDO for always-on automotive rails
The BU12JA2MNVX-CTL is a fixed 1.2 V output LDO from ROHM's automotive-grade series, qualified to AEC-Q100. It delivers 200 mA continuous output with a maximum dropout of 0.9 V at full load — the input rail must stay at least 0.9 V above 1.2 V across the operating range to keep the output in regulation. The 90 µA quiescent current suits always-on modules — body controllers, gateway ECUs, or sensor power supplies — that must stay under a sleep-current budget while the ignition is off.
PSRR and protection — what the numbers mean for the rail
PSRR is 70 dB at 1 kHz — the LDO attenuates 1 kHz ripple on the input by a factor of 3160. Upstream switching noise from a buck converter or alternator ripple at that frequency is effectively removed before it reaches the load. Above 100 kHz the rejection rolls off, so the input filter ahead of the LDO still matters for high-frequency hash. Built-in over-current and over-temperature protection prevent the regulator from failing short under a load fault or thermal runaway. The ON/OFF control pin lets a system supervisor or ignition signal gate the output — useful for sequencing multiple rails in a power-up scheme.
Housed in a 4-UDFN exposed pad package (SSON004R1010), the part is surface-mount with a thermal pad underneath. The fixed 1.2 V output means no feedback resistor divider is needed; the BOM rail voltage is locked.
Listed as active with ROHS3 compliance.