PNP small-signal transistor for general-purpose switching and amplification
The ROHM 2SA1037AKT146R is a PNP epitaxial planar transistor in a three-lead SOT-23-3 surface-mount package, designed for general-purpose switching and amplifier applications. The 140 MHz transition frequency keeps switching edges clean for moderate-speed digital or analog stages, though it is not intended for RF power or high-current regulation.
The SOT-23-3 footprint (TO-236-3 / SC-59) is a compact three-lead SMD that reflows well with standard profiles. The small thermal mass means it heats up fast under a hot-air station; use a fine nozzle at 300 °C and lift the part, not the pad. No exposed pad, so no via-stitch requirement. The 200 mW power limit is the package ceiling — derate above 25 °C ambient per the datasheet curve if dissipating near the max.