AEC-Q101 automotive-qualified NPN transistor in SOT-23
The Infineon BC817K-16E6327 is an NPN bipolar junction transistor in the BC817K series, explicitly qualified to AEC-Q101 for automotive-grade applications. It is housed in a PG-SOT23 surface-mount package (equivalent to TO-236-3 / SC-59 / SOT-23-3) and rated for a maximum collector current of 500 mA with a collector-emitter breakdown voltage of 45 V. The DC current gain (hFE) at 100 mA / 1 V is a minimum of 100 — the -16 gain group — and the transition frequency is 170 MHz. With a junction temperature rating of 150°C and 500 mW maximum power dissipation, this part is suited for switching and linear amplification in 12 V and 24 V automotive electrical systems, engine control modules, body electronics, and industrial control boards where the AEC-Q101 pedigree provides the PPAP-ready documentation an OEM auditor expects.
The 500 mA maximum collector current (Ic) is the continuous rating; the part can handle higher peak currents as long as the junction temperature stays within the 150°C TJ limit. For a typical automotive relay or solenoid driver, leaving 20 % derating margin means sizing the load to 400 mA or less. The 45 V VCEO breakdown provides adequate headroom for 12 V and 24 V systems, including load-dump transients that can exceed 40 V in an unclamped 12 V bus.
hFE of 100 at 100 mA — gain for saturated switching
The minimum DC current gain of 100 at Ic = 100 mA / VCE = 1 V means the base drive requirement is roughly 1 mA per 100 mA of collector current. For a 500 mA load, a base current of 5 mA saturates the transistor with VCE(sat) typically under 700 mV. This gain group (-16) covers hFE values from 100 to 250, giving consistent saturation behaviour across the reel. The 100 nA maximum collector cut-off current (ICBO) ensures negligible leakage at high temperature, important in automotive off-state current budgets.