NPN pre-biased transistor with integrated bias resistors
The Infineon BCR108E6433HTMA1 is an NPN pre-biased transistor in a SOT-23-3 package, integrating a 2.2 kΩ base resistor and a 47 kΩ emitter-base resistor. It switches loads up to 100 mA collector current at a 50 V collector-emitter breakdown voltage, with a 170 MHz transition frequency. The built-in bias network eliminates two external resistors per channel, saving board area and reducing pick-and-place cost in high-volume digital switching, relay drivers, and logic-level interface circuits.
New designs should evaluate a pin-compatible pre-biased NPN transistor in the same SOT-23-3 footprint to avoid a future last-time-buy event.
The 100 mA maximum collector current and 200 mW power dissipation limit this part to low-current switching — think driving a small relay coil, an LED string, or a logic-level buffer. The 100 nA collector cutoff leakage suits battery-powered or high-impedance nodes where off-state current matters.
SOT-23-3 — rework-friendly footprint
The SOT-23-3 package is one of the easiest small-signal packages to rework by hand. With a hot-air station at 300°C and a fine tip, you can lift the part without lifting the pad, provided the board has adequate copper relief. The PG-SOT23 supplier device package is electrically identical to the standard SOT-23-3 footprint.