Pre-biased PNP in a small SC-70 package
It integrates two 22 kOhm resistors — one in series with the base (R1) and one between the emitter and base (R2) — so it switches on with a positive base voltage relative to the emitter, no external bias resistors needed. Collector-emitter breakdown is rated at 50 V, continuous collector current at 100 mA, and the transition frequency hits 200 MHz, making it suitable for low-speed switching and driver stages in compact, cost-sensitive designs.
The 50 V VCEO and 100 mA Ic ceiling define the operating window for a substitute. The 200 MHz fT is adequate for switching up to a few megahertz; a faster device would work but may cost more. The SC-70 footprint is the mechanical constraint — any drop-in alternate must be in the same SOT-323 package.