PNP pre-biased transistor with integrated bias network
The Infineon BCR 162 B6327 is a PNP pre-biased transistor in a SOT-23-3 package. It integrates two 4.7 kOhm resistors — one in series with the base, one from base to emitter — so the designer gets a complete switching stage in a single surface-mount device. This eliminates two passives from the BOM and shrinks the layout for low-side load switching, relay drivers, or logic-level interface circuits where the base drive is already set by the resistor divider.
Rated for a continuous collector current of 100 mA and a collector-emitter breakdown voltage of 50 V, this part handles the common 24 V industrial logic rail and 5 V / 12 V relay coils with margin. The 200 mW power dissipation limit in the SOT-23-3 body means the designer should check the junction temperature at the actual load current and ambient — at 100 mA continuous with a 300 mV Vce(sat) the dissipation is only 30 mW, well inside the budget, but a higher Vce from insufficient base drive could eat into that headroom.