Automotive-grade NPN for general-purpose switching and drive
The Infineon BC817K-25E6327 is an NPN bipolar junction transistor from the automotive-qualified BC817K series, carrying AEC-Q101 certification for use in vehicle electronics. With a DC current gain (hFE) of 160 minimum at 100 mA collector current and a transition frequency of 170 MHz, this part suits relay and solenoid drivers, load switches, and signal amplification stages in automotive body control modules, infotainment, and power distribution units.
Gain and drive margin at 100 mA
The hFE of 160 minimum at 100 mA and 1 V VCE gives a guaranteed current gain that allows a microcontroller GPIO (3.3 V logic, 5 mA drive) to saturate the transistor and switch a 500 mA load. The 700 mV VCE(sat) maximum at 50 mA base and 500 mA collector confirms the transistor will saturate cleanly in high-side or low-side switching configurations, keeping dissipation within the 500 mW package limit.
Package and thermal considerations for SOT-23
The SOT-23-3 footprint (TO-236 / SC-59 variant) is a common small-signal transistor land pattern. For continuous operation near 500 mA and 1 V VCE(sat), the junction temperature approaches the 150 °C rating — derating is advised for ambient temperatures above 85 °C.
There is no imminent supply risk for production builds.