Automotive-grade NPN small-signal transistor in SOT-323
The Infineon BC817K-25WH6433 is an NPN bipolar junction transistor qualified to AEC-Q101, aimed at automotive and industrial applications where a known reliability level is required. It delivers a collector-emitter breakdown voltage of 45 V and can handle a continuous collector current of 500 mA, making it suitable for driving relays, solenoids, and low-power loads in 12 V or 24 V vehicle systems. The device is housed in a PG-SOT323-3-1 surface-mount package (SC-70/SOT-323 footprint), with a maximum power dissipation of 500 mW.
Gain bracket and switching performance
The -25 suffix denotes a DC current gain (hFE) range of 160 to 250 at a test condition of 100 mA collector current and 1 V Vce. This gain band is a common choice for medium-drive switching and linear pre-driver stages where a predictable current gain is needed without the wider spread of the -16 or -40 grades. The 170 MHz transition frequency is adequate for switching applications up to a few megahertz and for analog amplification in audio or sensor signal paths. Saturation voltage is specified at 700 mV maximum when driven with 50 mA base current into a 500 mA collector load, which is typical for a 45 V NPN of this die size.
Lifecycle and compliance
The AEC-Q101 qualification covers automotive-grade stress tests including high-temperature reverse bias, temperature cycling, and humidity. RoHS compliance is standard for Infineon's lead-free product lines; no separate lead-free certification is required for ordering.