45 V, 500 mA NPN in a SOT-323 footprint
The BC 817-25W E6327: The Infineon BC 817-25W is a general-purpose NPN bipolar transistor in the compact SC-70 (SOT-323) surface-mount package. It handles a 45 V collector-emitter breakdown and 500 mA continuous collector current, making it a fit for low-to-medium current switching and linear amplification in space-constrained designs. The -25W suffix selects a DC current gain bracket of 160 minimum at 100 mA collector current and 1 V Vce, which is the mid-range gain group for the BC 817 family.
With a transition frequency of 170 MHz, this transistor is fast enough for general-purpose switching up to a few megahertz and for analog amplifier stages in the audio band and low RF. The 250 mW power dissipation limit in the SOT-323 body is the real constraint — continuous collector current near the 500 mA maximum will exceed the package's thermal capability unless the duty cycle is low or the ambient is well below the 150°C junction temperature rating. For a saturated switch at 100 mA, the 700 mV Vce(sat) maximum at 50 mA base drive is typical for a medium-gain NPN.
Infineon has classified the BC 817-25W E6327 as obsolete. That means the manufacturer has stopped production and no further last-time-buy windows are open through the factory channel. Any available stock is what remains in the independent distribution pipeline. When you source this part through us, we confirm the date-code provenance and condition before quoting — every lot is sourced against your RFQ, not from a standing inventory that may have sat past its moisture-sensitivity floor life.
Pin-compatible alternatives and the BC 817 gain group
The -25W designates a specific hFE range of 160 to 400 at 100 mA. If the exact gain bin is not critical to the circuit's bias point, a standard BC 817-25 or BC 817-40 in the same package may work with a resistor adjustment. For a direct replacement with identical gain grouping, look for a BC 817-25W from another manufacturer that still produces the part — but verify the package suffix matches the SOT-323 variant. No official Infineon successor has been released for this order code.