Pre-biased NPN in a small SOT-323 package
The Infineon BCR135WH6327XTSA1 is an NPN pre-biased transistor in the SC-70 (SOT-323) surface-mount package, integrating a 10 kOhm base resistor and a 47 kOhm emitter-base resistor. This built-in bias network reduces external component count in switching and interface applications where a single transistor with known turn-on characteristics is needed.
Last Buy — plan the BOM transition
Infineon has placed the BCR135WH6327XTSA1 into Last Buy status. This means the factory has a final order window; after that date, new-issue supply will come only from the independent surplus and broker channel. For a production BOM that depends on this exact order code, the sourcing strategy needs to secure the last-time-buy quantity or qualify a replacement before the window closes.
Ratings that matter for the design
The 50 V collector-emitter breakdown voltage and 100 mA maximum collector current cover low-side switching, level shifting, and signal gating in 3.3 V to 24 V logic and industrial control circuits. The 150 MHz transition frequency means it switches cleanly at moderate speeds — suitable for GPIO-driven loads and low-frequency PWM, not for RF output stages. The 250 mW power dissipation limit in the SOT-323 package is the thermal ceiling: at 5 V and 10 mA the junction stays well within the safe area, but driving a 100 mA load near the Vce saturation voltage of 300 mV at 500 µA base current needs a check against the derating curve.
