The Infineon BCR198B6327HTLA1 is a PNP pre-biased transistor in a PG-SOT23 package. It integrates two 47 kΩ resistors — one in series with the base (R1), one from base to emitter (R2) — so you can drive it directly from a logic output without external bias components. The 50 V collector-emitter breakdown and 100 mA collector current rating suit low-power switching loads like relay drivers, LED indicators, or level shifters in industrial and consumer boards. The 190 MHz transition frequency gives it enough bandwidth for moderate-speed switching up to a few megahertz.
50 V / 100 mA — sizing the switching load
With a VCE(max) of 50 V and IC(max) of 100 mA, this transistor handles typical 12 V or 24 V relay coils, small solenoids, and indicator LEDs. The saturation voltage is 300 mV at 500 µA base current and 10 mA collector current, so it stays cool in lightly loaded switching. For loads above 80 mA, check the power dissipation ceiling of 200 mW — at 50 V and 100 mA you'd exceed that, so derate the current or voltage accordingly.
Obsolete — sourcing reality
Infineon lists the BCR198B6327HTLA1 as obsolete. If you are designing a new board, look at current Infineon pre-biased PNP families in SOT-23 with similar resistor values; the pinout is standard across the series, so a drop-in replacement may exist with a different base resistor ratio.