Automotive-grade pre-biased PNP for load-switching and interface circuits
The Infineon BCR191 is a PNP pre-biased transistor — a digital transistor with two 22 kΩ resistors (R1 and R2) integrated into the package. It is qualified to AEC-Q101, making it suitable for automotive environments where reliability screening and extended temperature operation are required. The device switches loads up to 100 mA collector current and blocks up to 50 V, with a transition frequency of 200 MHz, so it handles low-speed switching and level-shifting in ECU, sensor, and actuator interface circuits.
Built-in bias resistors simplify the BOM
The BCR191 integrates a 22 kΩ base resistor (R1) and a 22 kΩ emitter-base resistor (R2), eliminating two external passives per transistor. That saves board space and reduces pick-and-place cost — useful when populating multiple channels on a dense automotive PCB. The pre-biased topology also guarantees a known on/off threshold without trimming, which tightens the spread across temperature and lot.
Surface-mount SC-70 / SOT-323 package
Housed in a SC-70 / SOT-323 package (Infineon code PG-SOT323-3-1), the BCR191 is a three-pin surface-mount device. The small footprint suits space-constrained layouts in engine control modules, body controllers, and sensor modules. Maximum power dissipation is 250 mW — derate according to the thermal resistance of the board copper area when running near the limit.