9V fixed output, 2A continuous — the dropout ceiling at full load
The BA90DD0T is a single-output positive linear regulator from ROHM Semiconductor, delivering a fixed 9V rail at up to 2A. Quiescent current is 120 µA typical, so the regulator's own draw is negligible against the load current — it does not materially affect efficiency in always-on rails where the load cycles between sleep and active.
TO-220FP-3 — through-hole mounting and thermal path
The full-pack TO-220-3 (TO-220FP-3) isolates the metal tab from the die, so the back of the package can be bolted to a heatsink or chassis without an insulating pad.
Protection set — over-current, over-temperature, over-voltage
Built-in over-current, over-temperature, and over-voltage protection circuits cover the common failure modes: a shorted load triggers current limiting before the junction exceeds the 125°C limit; an over-voltage event on the input clamps the output. The part does not require an external protection diode for reverse-bias conditions — the internal structure handles it.