Dual pre-biased transistor for automotive and space-constrained designs
The Infineon BCR35PNH6433 is a dual NPN/PNP pre-biased transistor in a single SOT-363 package, qualified to AEC-Q101 for automotive applications. Each transistor integrates base bias resistors (R1 = 10kΩ, R2 = 47kΩ), eliminating two external resistors per channel and simplifying PCB layout. With a 50V collector-emitter breakdown voltage and 100mA maximum collector current, it suits 12V and 24V automotive loads, relay drivers, and logic-level interface circuits where board space is tight.
Key ratings for the BOM decision
The 50V VCEO breakdown gives ample headroom for 12V and 24V automotive power rails, including load-dump transients. The 100mA collector current rating covers most low-side switch and signal-level driver applications. The 150MHz transition frequency ensures adequate switching speed for PWM and digital interface signals up to several MHz. The 300mV saturation voltage at 500µA base current and 10mA collector current keeps conduction losses low in saturated switching. The integrated 10kΩ base resistor and 47kΩ base-emitter resistor set a fixed bias point, so the transistor turns on with a typical logic-level input (3.3V or 5V) without external components. This simplifies the BOM and reduces placement cost, particularly in high-volume automotive modules.
Package and footprint
Housed in a PG-SOT363-6-1 (SC-88) surface-mount package, the BCR35PNH6433 occupies roughly 2.1mm × 2.0mm of board area. The 250mW power dissipation limit governs thermal design — ensure adequate copper area on the PCB for heat spreading when driving near the 100mA collector current continuously.