Small-signal PNP in a tiny SMD package
It comes in the SC-75 / SOT-416 package (ROHM designates the supplier device package as EMT3), a three-lead surface-mount case about 1.6 x 0.8 mm — roughly the size of a 0805 resistor. The 140 MHz transition frequency puts it in the small-signal switching and amplifier class, not a power device.
The 50 V Vceo and 150 mA Ic are the hard ceilings for the collector circuit. The 150 mW maximum power dissipation is the real limiter in this tiny package — at 150 mA you're already at the Vce(sat) drop of 500 mV (at 5 mA base, 50 mA collector), which eats 75 mW. Push the dissipation past 150 mW and the junction temperature climbs above the 150°C rating; there's no heatsink on an SC-75, so the ambient and the copper pad area are what keep it alive. The 100 nA collector cutoff (ICBO) is low enough for most battery-operated bias networks.
ROHS3 compliant — no exemptions that expire soon.