Two NPNs with bias resistors baked in
The Toshiba RN1608(TE85L,F) packs two NPN transistors plus their base bias network — a 22 kΩ series resistor and a 47 kΩ resistor from base to emitter — into a single SC-74 (SOT-457) package.
Transition frequency of 250 MHz is more than adequate for logic-level translation up into the low-MHz range and for switching loads like relay coils or LED strings where the 100 nA collector cutoff keeps off-state leakage negligible. The 300 mV saturation at 250 µA base drive and 5 mA collector current means the output stage stays cool driving modest loads; the 80 minimum hFE at 10 mA, 5 V confirms decent gain headroom for typical microcontroller interface levels.
SC-74 package — footprint and thermal reality
The SC-74 (SOT-457) is a six-lead surface-mount package. The 300 mW maximum power dissipation is the total for both transistors combined — if you run both channels at high current, derate accordingly. The SM6 supplier device package code is Toshiba's internal designation for this footprint; the standard SOT-457 land pattern applies.