1.2V fixed rail for automotive ECUs — the LDO that cleans up the supply
The ROHM BU12SD2MG-MTR is a single-output positive fixed LDO regulator delivering 200 mA at 1.2 V from a maximum 6 V input rail. The 68 dB PSRR at 1 kHz means this LDO attenuates switching ripple from a pre-regulator or alternator noise by a factor of roughly 2500 — a 100 mVpp ripple on the input becomes roughly 40 µVpp on the output, which keeps the analog supply clean for sensor interfaces or microcontroller ADC references.
Dropout and quiescent — the headroom and idle draw
Maximum dropout is 0.55 V at 100 mA load.
Package and board-fit for the 5-SSOP
Supplied in SC-74A / SOT-753 (5-SSOP), a 5-lead surface-mount package roughly 2.9 mm × 1.6 mm. The enable pin allows the system processor to shut down the LDO output during standby, cutting the load current to the quiescent level. Protection features include over-current and over-temperature shutdown — the LDO folds back or latches off before the junction exceeds the safe operating area, which is important in an automotive environment where the ambient can spike above the 105 °C rated limit during a fault condition.