Pre-biased PNP in a small SC-70 package
The Infineon BCR191WE6327HTSA1 is a PNP pre-biased digital transistor in a SC-70 (SOT-323) surface-mount package. It integrates two 22 kOhm resistors — one in series with the base (R1) and one between the emitter and base (R2) — so it switches on with a positive base voltage relative to the emitter, no external bias resistors needed. Collector-emitter breakdown is rated at 50 V, continuous collector current at 100 mA, and the transition frequency hits 200 MHz, making it suitable for low-speed switching and driver stages in compact, cost-sensitive designs.
Infineon has marked the BCR191WE6327HTSA1 as Obsolete.
The 50 V VCEO and 100 mA Ic ceiling define the operating window for a substitute. The 300 mV saturation voltage at 500 µA base drive and 10 mA collector current is typical for a pre-biased PNP — a replacement should match or beat that to avoid excess dissipation in the on-state. The 200 MHz fT is adequate for switching up to a few megahertz; a faster device would work but may cost more. The SC-70 footprint is the mechanical constraint — any drop-in alternate must be in the same SOT-323 package.