The Infineon BCR112WE6327BTSA1 is an NPN pre-biased transistor — a digital transistor with a 4.7 kΩ base resistor (R1) and a 4.7 kΩ emitter-base resistor (R2) integrated into the same SC-70 SOT-323 package. This configuration eliminates the two external resistors normally needed for a saturated switch, saving board area and BOM line items in high-volume designs. With a collector current rating of 100 mA and a collector-emitter breakdown voltage of 50 V, it handles typical low-side switching loads like relay coils, LED strings, and logic-level interface circuits in consumer, industrial, and automotive modules.
Switching performance at low base drive
The Vce saturation is specified at 300 mV maximum with only 500 µA base current driving 10 mA collector current. The 140 MHz transition frequency confirms it can handle PWM frequencies well into the megahertz range, though practical switching speed in a saturated circuit will be lower due to storage time.
Infineon lists the BCR112WE6327BTSA1 as obsolete. No successor order code appears on the official record. If you have this on a BOM, you are looking at last-time-buy or surplus-channel sourcing. The SC-70 SOT-323 footprint is shared by many pre-biased NPN transistors from multiple manufacturers, but a drop-in replacement requires matching the 4.7 kΩ / 4.7 kΩ resistor divider, the pinout (base-collector-emitter in SOT-323), and the 100 mA / 50 V ratings. A direct cross to a DTC143 series part, for example, would need checking — DTC143 uses a different resistor ratio (4.7 kΩ / 4.7 kΩ in some variants, 10 kΩ / 10 kΩ in others).
Package and board-fit note
Surface-mount in SC-70 (also called SOT-323), supplier package designation PG-SOT323. The 250 mW power dissipation limit means you cannot pull 100 mA continuously at any significant Vce — derate for ambient temperature above 25 °C. For a 10 mA load at 300 mV saturation, dissipation is only 3 mW, well within the budget.