Dual pre-biased NPN in a SOT-363
The BCR 141S E6727: Two NPN pre-biased transistors in a single SOT-363 package, each with 22kΩ series base and base-emitter resistors built in. This saves board space and external resistor count in switching and driver stages where the bias network is fixed.
The 50V Vce(max) gives comfortable headroom for 24V industrial rails and 12V automotive loads, though the part is not AEC-Q qualified. The 100mA Ic(max) is a per-transistor limit; the 250mW total package dissipation means you cannot run both transistors at full current simultaneously in a warm environment — derate for ambient temperature. The 300mV saturation voltage at 10mA is typical for a pre-biased part; expect a few hundred mV drop in the on-state, which matters if you are driving a low-voltage logic input. The minimum hFE of 50 at 5mA, 5V confirms adequate gain for most switching applications, but the integrated resistors set the base drive, so the actual forced beta is fixed by the 22kΩ R1.
Obsolete — sourcing and replacement reality
Infineon lists the BCR 141S as obsolete. No official successor part number appears in the record. For new designs, look at the current Infineon pre-biased dual NPN family in SOT-363 — the bias resistor combination (22kΩ base, 22kΩ base-emitter) is a common value, so a direct-fit replacement likely exists.