Pre-biased NPN in SC-70 — why the integrated resistors matter
The Infineon BCR108WH6327 is a pre-biased NPN transistor that integrates the base bias resistor (R1 = 2.2 kOhms) and a base-emitter resistor (R2 = 47 kOhms) into a single SC-70 / SOT-323 package. This eliminates two external passives from the board, shrinking the footprint and reducing pick-and-place cost on high-volume assemblies. It is rated for a collector current of 100 mA and a collector-emitter breakdown voltage of 50 V, with a transition frequency of 170 MHz — suitable for switching and interface applications up to the low-MHz range.
250 mW power dissipation in a SOT-323 footprint
Maximum power dissipation is 250 mW. In a SOT-323 case, that limits continuous collector current in free air — at 100 mA the device is near its thermal ceiling unless the duty cycle is low or the ambient is well below 85 °C. For linear-mode operation at higher currents, budget the junction temperature rise against the 250 mW ceiling.