Dual NPN pre-biased in SOT-563 — BOM simplification for low-power switching
The RN1910FE,LF(CT integrates two NPN transistors with built-in bias resistors (R1 = 4.7 kΩ) in a single SOT-563 / ES6 package. The 100 mW total power dissipation limits continuous duty in warm environments — derate for ambient above 25 °C if both channels run near the ceiling. The 250 MHz transition frequency keeps switching clean up into the low-MHz range, though the pre-biased configuration is primarily aimed at saturated on/off switching rather than linear amplification.
The 50 V collector-emitter breakdown provides comfortable margin for 24 V industrial rails and 12 V automotive loads, but leaves no headroom for 48 V bus voltages. The 100 mA continuous collector current suits small relays, solenoids, and LED strings; for loads above 80 mA, check the total package dissipation against the 100 mW ceiling, especially when both transistors are active simultaneously. The 300 mV saturation voltage at 250 µA base / 5 mA collector is typical for a pre-biased part at low current; expect higher Vce(sat) near the 100 mA limit.