Dual pre-biased NPN in a 6-pin SOT-363
The ROHM UMH37NTN packs two NPN transistors with integrated bias resistors into a single SOT-363 (UMT6) package. Each transistor has a 10 kΩ base resistor (R1) and is rated for 20 V collector-emitter breakdown and 400 mA continuous collector current. The pre-biased configuration means the base drive resistor is already on-die, saving two external resistors per channel and shrinking the board footprint for switching loads like relay coils, solenoid drivers, or LED indicators. The low Vce(sat) of 100 mV maximum at 30 mA keeps conduction losses minimal in low-voltage switching. The 150 mW total power dissipation limits continuous current in free air; for loads above 100 mA per channel, check the derating against ambient temperature.
The surface-mount package is suited for automated assembly and reflow soldering. No special thermal management is needed at the 150 mW power level, but the small package limits heat sinking — keep trace connections to the collector pads generous if running both channels near the current limit.