3.3V fixed LDO with 1.5A output for automotive power rails
The BD33HC5MEFJ-ME2 is a positive fixed-output LDO voltage regulator from ROHM Semiconductor, part of the Automotive series qualified to AEC-Q100. It delivers a regulated 3.3V rail at up to 1.5A continuous output current from a maximum input of 8V. The 1.2V maximum dropout at full 1.5A load defines the minimum headroom needed between the input rail and the 3.3V output — below that margin the regulator falls out of regulation. For a 5V input bus, the 1.7V differential provides comfortable margin even under transient dips.
Thermal and protection features for automotive environments
The 8-SOIC exposed-pad package (8-HTSOP-J) routes heat through the thermal pad to the PCB copper plane — layout must connect the pad to a sufficient copper area to keep junction temperature within limits at 1.5A load. Built-in protection includes over-current and over-temperature shutdown plus a soft-start feature that limits inrush current during power-up. The quiescent current is 0.6 mA typical, and the maximum supply current is 1.2 mA — relevant for always-on modules where the regulator's own draw must be budgeted against the system sleep current. An Enable control pin allows the output to be switched off externally, dropping the load current to near-zero for power-save modes. The output configuration is positive with a fixed 3.3V set point — no external resistor divider is needed for the output voltage.