Pre-biased PNP in a tiny footprint
The Infineon BCR 191L3 E6327 is a PNP pre-biased transistor — the 22 kOhms base resistor (R1) and 22 kOhms emitter-base resistor (R2) are integrated on-chip, saving two external passives and one placement step per channel on the pick-and-place line. It comes in the SC-101 (SOT-883) package, a three-lead leadless package suited for dense portable or module-level designs where board area is at a premium.
Switching speed and drive headroom
Transition frequency of 200 MHz means this part handles switching up into the low-VHF range — think load switches for RF front-ends or level shifters in sensor interfaces running a few megahertz. The 50 V collector-emitter breakdown gives comfortable margin for 24 V industrial rails or 48 V telecom supplies, while the 100 mA continuous collector current covers small relay and LED drive. Saturation voltage is 300 mV at 500 µA base drive and 10 mA collector current, so it stays cool in saturated switching.
Power budget in the leadless package
Maximum power dissipation is 250 mW, which is the thermal ceiling for the PG-TSLP-3-4 (SOT-883) body. In a 25 °C ambient with no airflow, that limits continuous collector current to about 50 mA at 5 V Vce — above that, pulse duty cycling or a layout with thermal vias under the package is needed. The 100 nA collector cutoff (ICBO) ensures negligible leakage at high temperature, a common concern in automotive cabin or outdoor telecom enclosures.