Pre-biased NPN — one less resistor to place
The BCR 116T E6327: The Infineon BCR 116T is an NPN pre-biased digital transistor in a SC-75 SOT-416 surface-mount package. It integrates a 4.7 kΩ base resistor (R1) and a 47 kΩ base-emitter resistor (R2), so the switching threshold is set by the resistor divider rather than an external bias network. Collector-emitter breakdown is rated at 50 V, continuous collector current at 100 mA, and the transition frequency reaches 150 MHz — enough for low-speed switching, relay drivers, and logic-level translation up to a few megahertz.
R1 and R2 — what the ratio buys you
With R1 at 4.7 kΩ and R2 at 47 kΩ, the base current is limited while the emitter resistor provides a defined off-state. The minimum DC current gain is 70 at 5 mA collector current and 5 V VCE, and the saturation voltage is 300 mV maximum at 500 µA base drive and 10 mA collector current.