Obsolete — sourcing through independent distribution
The Infineon BCR 108F E6327 is an NPN pre-biased digital transistor, officially listed as obsolete. It integrates a 2.2 kΩ base resistor (R1) and a 47 kΩ emitter-base resistor (R2), eliminating the need for external biasing components in low-power switching circuits. With a collector-emitter breakdown voltage of 50 V and a maximum collector current of 100 mA, it suits relay drivers, LED drivers, and logic-level interface stages. The 170 MHz transition frequency keeps switching losses low in applications up to a few MHz.
Package and footprint — SOT-723
Housed in a SOT-723 package (Infineon code PG-TSFP-3), the BCR 108F E6327 measures roughly 1.2 x 1.2 mm — a tiny three-lead surface-mount package. Hand-soldering is possible with a fine tip and steady hands, but a hot-air station or reflow profile is more reliable. The 250 mW power dissipation limit means the part is intended for low-power signal switching, not continuous high-current loads.
Saturation and gain — what the numbers mean
VCE(sat) is specified at 300 mV maximum with a base current of 500 µA and collector current of 10 mA — a typical drive condition for saturating the transistor in a switching application. The minimum DC current gain (hFE) of 70 at 5 mA collector current and 5 V VCE gives enough headroom for logic-level drive. Collector cutoff current is a low 100 nA, so leakage won't load down a high-impedance node in off state.