PNP pre-biased transistor with integrated bias resistors
The Infineon BCR158W is a PNP pre-biased transistor in a compact SC-70 / SOT-323 package. It integrates a 2.2 kΩ base resistor (R1) and a 47 kΩ base-emitter resistor (R2), eliminating the need for external biasing components in digital switching applications. The device is rated for a collector-emitter breakdown voltage of 50 V and a continuous collector current of 100 mA, with a maximum power dissipation of 250 mW.
The 50 V VCEO breakdown gives headroom for switching 24 V or 48 V industrial loads, while the 100 mA continuous collector current handles small relays, LEDs, or logic-level interface signals. The 250 mW power limit in the SC-70 package means the device is suited for low-power auxiliary switching rather than output drivers — keep the load current and duty cycle within the thermal budget. The 200 MHz transition frequency is adequate for general-purpose switching up to several megahertz, but not for RF output stages.