The ROHM BD78310EFJ-ME2 is a Class AB monaural speaker amplifier delivering 1.6W into an 8Ω load from a single 5V supply. That power level suits dashboard chimes, seatbelt alerts, or any automotive cabin audio tone that doesn't need a full head-unit output stage. The 1.6W rating is specified per channel into 8Ω, so a single 8Ω speaker gets the full output; for a 4Ω load the available power will be higher but limited by the package thermal capability.
AEC-Q100 — why it matters for the BOM
This part carries the Automotive, AEC-Q100 series designation, meaning it has passed the Automotive Electronics Council's stress tests for ICs used in vehicle-mounted electronics. If your BOM requires a qualified automotive-grade audio amp, this is a direct fit — no need for a separate qualification run.
Supply and package realities
Supply voltage range is 4V to 5.5V, which aligns with standard automotive 5V rails and allows margin during cold-crank dips. Without that thermal connection, the junction temperature will exceed the 105°C limit under continuous full-power operation.
ROHS3 compliant.