Infineon Technologies BC 817-40W E6327

Overview

BC 817-40W E6327 from Infineon Technologies is an NPN silicon general-purpose audio-frequency transistor in SOT323 package, rated for 45 V V_CEO, 500 mA I_C, and minimum DC current gain (h_FE) of 250 at I_C = 100 mA / V_CE = 1 V. It delivers low V_CE(sat) ≤ 0.7 V at I_C = 500 mA / I_B = 50 mA and operates up to 150 °C junction temperature, commonly used in discrete switching and linear amplification stages of power supply feedback loops and LED drivers.

For engineers reviewing the BC 817-40W E6327 datasheet, BC 817-40W E6327 pinout, BC 817-40W E6327 application, or BC 817-40W E6327 equivalent, key selection criteria include verified h_FE group 40 performance across temperature, SOT323 thermal resistance (R_thJS ≤ 80 K/W), RoHS-compliant Pb-free construction, and AEC-Q101 qualification for automotive-grade reliability.

Technical Context

This transistor operates as a single-element NPN bipolar junction device optimized for linear amplification and saturated switching in low-to-medium power analog and digital interface circuits. Its design supports stable h_FE over wide collector current range (10 mA–500 mA) and maintains V_CE(sat) ≤ 0.7 V under high-current drive conditions.

The BC 817-40W E6327 features a maximum f_T of 170 MHz at I_C = 50 mA / V_CE = 5 V, C_cb = 3 pF at V_CB = 10 V, and C_eb = 40 pF at V_EB = 0.5 V - enabling use in AF signal paths up to several tens of MHz with predictable small-signal behavior.

Key Specifications

Pinout & Package

Package: SOT323 (SC-70), surface-mount, 3-terminal plastic package with standard lead pitch and thermal pad compatibility.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN general-purpose transistor applications.

Compared with BC817-40W E6327, BC847BW offers lower cost but reduced h_FE consistency at high current, while MMBT3904LT1G provides broader industry availability but inferior thermal performance and unverified high-current gain behavior.

Availability

BC 817-40W E6327 is available at Aetrix Electronics and suitable for automotive lighting control, industrial sensor interface, DC-DC converter feedback, and relay driver applications requiring stable component supply, AEC-Q101 compliance, and SOT323 thermal performance.

Supply support for BC 817-40W E6327 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Infineon Technologies is a German semiconductor manufacturer specializing in power management, automotive electronics, and industrial control ICs and discrete devices.

The BC817 series belongs to Infineon's AEC-Q101-qualified general-purpose transistor product line, designed specifically for robust, high-reliability switching and amplification in automotive and industrial environments.

FAQ

Is BC 817-40W E6327 pin-compatible with BC817-40?

Yes - both share identical SOT323 pinout (B-E-C), but BC817-40W E6327 uses a thermally enhanced variant with R_thJS ≤ 80 K/W versus 70 K/W for BC817-40 in SOT23. The SOT323 package has different mechanical dimensions and thermal characteristics, so PCB layout must match the SOT323 footprint.

What does the "40" in BC 817-40W indicate?

The "40" denotes h_FE group 40, specifying a guaranteed minimum DC current gain of 250 at I_C = 100 mA / V_CE = 1 V, with typical values reaching 400–630. This distinguishes it from BC817-16 (h_FE = 100–160) and BC817-25 (h_FE = 160–250), enabling tighter base drive tolerance in production designs.

Can BC 817-40W E6327 replace BC847 in existing designs?

Only with verification: BC847 variants typically have lower V_CEO (45 V same), but h_FE group B (110–220) is significantly lower than BC817-40W's 250–630. Base resistor values must be recalculated, and thermal performance must be re-evaluated due to differing R_thJS and package types (SOT323 vs SOT23).

Does BC 817-40W E6327 support pulsed operation beyond 500 mA?

Yes - peak collector current I_CM is rated at 1000 mA for pulse widths < 300 µs with duty cycle < 2%. Permissible pulse load curves in the datasheet confirm P_tot(max)/P_tot(DC) ratios up to 10× for short durations, provided junction temperature remains within 150 °C limits.