8V fixed output, 300 mA — the dropout and the thermal pad decide the board fit
The BD80GA3MEFJ-ME2 is a single-output positive LDO from ROHM's automotive series, delivering a fixed 8 V at up to 300 mA. The 8-SOIC package with exposed pad (8-HTSOP-J) routes heat through the pad to the board copper — the RthJA depends on the pad area and via count, not just the ambient. For a 300 mA load at 14 V input, the 1.8 W dissipation demands a solid thermal land on the PCB.
Automotive temperature grade and protection suite
Qualified to AEC-Q100, the device operates from -40°C to 105°C ambient — the under-hood temperature band where an engine-bay ECU or transmission controller sees sustained 85°C plus transients. The 14 V max input covers nominal 12 V systems with load-dump margin. Built-in over-current and over-temperature protection, plus a soft-start ramp, handle the inrush into a discharged output capacitor without triggering the current limit. The enable pin lets a supervisor or GPIO sequence the rail on and off.
Quiescent current and supply budget
Quiescent current is 600 µA typical, with a maximum supply current of 1.2 mA — the LDO's own draw is well below the load current, but for always-on modules in the vehicle this Iq adds to the dark-current budget. The 600 µA figure is the standing loss when the output is enabled but unloaded.