What this PNP pre-biased transistor does
The Infineon BCR158WE6327HTSA1 is a PNP pre-biased transistor in a SC-70 SOT-323 surface-mount package. It integrates a 2.2 kOhm base resistor (R1) and a 47 kOhm emitter-base resistor (R2), which simplifies board layout by reducing external component count. With a collector-emitter breakdown voltage of 50 V and a continuous collector current rating of 100 mA, it suits low-power switching and interface circuits in industrial control, consumer electronics, and general-purpose load driving. The 200 MHz transition frequency supports moderate-speed switching applications.
This part carries an obsolete product status.
The 50 V collector-emitter breakdown sets the maximum rail voltage this transistor can handle — stay below that for reliable switching. The 100 mA continuous collector current defines the load it can drive; for inductive loads or higher inrush, derate accordingly. The 250 mW power dissipation limit is the package ceiling at 25 °C ambient; in a dense SMT layout or elevated temperature, the usable current drops. The 70 minimum hFE at 5 mA, 5 V ensures adequate gain for base-drive calculations in saturated switching.
