Pre-biased NPN — what the built-in resistors buy you
The Infineon BCR142B6327HTLA1 is an NPN pre-biased transistor in a PG-SOT23 package. It integrates a 22 kΩ base resistor (R1) and a 47 kΩ emitter-base resistor (R2), eliminating two external passives from the board — a space and placement-cost win for high-volume switching loads like relay drivers, LED indicators, and logic-level interface circuits. Collector-emitter breakdown is rated at 50 V, with a maximum collector current of 100 mA and a transition frequency of 150 MHz — adequate for low-frequency switching up to a few hundred kilohertz. Saturation voltage is 300 mV at 500 µA base drive and 10 mA collector current, keeping conduction losses modest in saturated switching. DC current gain minimum is 70 at 5 mA, 5 V, and collector cutoff current is just 100 nA, so off-state leakage won't load a CMOS output or pull down a bias rail.
Infineon lists the BCR142B6327HTLA1 as Obsolete. No last-time-buy window remains open through the factory channel. Because the pre-biased resistor network is the distinguishing feature, a direct replacement must match the 22 kΩ / 47 kΩ divider ratio and the PG-SOT23 footprint. The BCR142 family shares the same base part number; other suffix variants may carry different resistor values or package options — verify the full order code before substituting.