Built-in bias resistors shrink the BOM
The RN1415,LF is a Toshiba NPN pre-biased transistor that integrates a 2.2 kΩ base resistor (R1) and a 10 kΩ base-emitter resistor (R2) inside the package. That means you skip two external passives and the associated PCB real estate — a clean fit for dense boards where every 0402 counts.
Maximum power dissipation is 200 mW, which limits continuous collector current depending on the Vce drop. At 5 mA Ic and 300 mV Vce(sat) (the rated saturation condition at 250 µA base drive), dissipation is roughly 1.5 mW — well within margin. If you push closer to 100 mA continuous at higher Vce, the thermal budget fills fast; the SOT-23-3 package has modest copper area for heat spreading. Keep the ambient below 85 °C for sustained high-current duty, or derate accordingly.
No last-time-buy or discontinuation notice is in effect. If you need a second-source option, the RN1417(TE85L,F) is a functional peer with different internal resistor values (10 kΩ base, 4.7 kΩ base-emitter) — verify the bias network matches your drive conditions before substituting.