Infineon Technologies BC 817K-25W E6433

Overview

BC817K-25W from Nexperia is an NPN silicon general-purpose audio-frequency transistor in SOT323 package, featuring 45 V V_CEO, 250 mA I_C (DC), h_FE = 160–400 (at I_C = 100 mA), V_CE(sat) ≤ 0.7 V (at I_C = 500 mA, I_B = 50 mA), and RoHS-compliant construction. It serves as a low-voltage switching and amplification device in automotive signal conditioning and industrial sensor interface circuits.

For engineers reviewing the BC817K-25W datasheet, BC817K-25W pinout, BC817K-25W application, or BC817K-25W equivalent, this page delivers verified electrical parameters, thermal derating curves, h_FE group-specific gain behavior across temperature, and validated SOT323 terminal mapping for PCB layout and reliability validation.

Technical Context

This transistor operates in linear and saturation regions with guaranteed DC current gain grouping (h_FE-grp.25: 160–400 at I_C = 100 mA, V_CE = 1 V) and supports pulsed operation up to 1 A peak collector current. Its f_T = 170 MHz enables stable small-signal amplification up to mid-VHF range.

Thermal design is constrained by R_thJS ≤ 80 K/W (SOT323 package, T_S ≤ 130 °C), and maximum power dissipation drops linearly from 250 mW at T_S = 25 °C to zero at T_S = 130 °C - critical for thermally dense automotive modules.

Key Specifications

Pinout & Package

SOT323 (SC-70) surface-mount plastic package, 3-terminal, lead-free, RoHS-compliant. Dimensions: 2.2 × 2.2 × 0.95 mm (L × W × H), standard tape-and-reel packaging.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC847BW and MMBT3904LT1G, BC817K-25W uniquely combines AEC-Q101 qualification, 45 V breakdown, and h_FE group binning in SOT323 - making it optimal for automotive signal switching where reliability and thermal density are prioritized over absolute gain ceiling.

Availability

BC817K-25W is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor interfaces, and medical front-end buffers requiring stable component supply, long-term lifecycle support, and traceable RoHS-compliant sourcing.

Supply support for BC817K-25W 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

Nexperia is a global semiconductor expert focused on essential semiconductors, delivering high-performance, reliable discrete and logic devices for automotive, industrial, and consumer markets.

BC817K-25W belongs to Nexperia's BC817K/BC818K family of AEC-Q101-qualified general-purpose transistors designed specifically for robust signal switching and amplification in harsh-environment automotive electronics.

FAQ

What is the maximum allowable base current for continuous operation?

The absolute maximum DC base current (I_B) is 100 mA per datasheet Section 2. Maximum Ratings. However, for reliable long-term operation at ambient temperatures up to 85 °C, design practice limits I_B to ≤ 20 mA to prevent excessive junction heating and maintain h_FE stability across temperature.

Does BC817K-25W support pulsed collector currents above 500 mA?

Yes - the peak collector current (I_CM) is rated at 1000 mA for pulse widths < 300 µs and duty cycle < 2 %. This capability is validated in the datasheet's permissible pulse load curves (Fig. 7–8), enabling short-duration surge handling in relay drive and fault protection circuits.

How does h_FE vary with temperature for group 25 devices?

At I_C = 100 mA and V_CE = 1 V, h_FE for group 25 decreases approximately 25 % from 25 °C to 105 °C, remaining within 120–300 range. The datasheet's Figure 5 shows this monotonic decline, confirming usable gain down to –40 °C and up to 105 °C junction temperature.

Can BC817K-25W replace BC817-25 in existing SOT23 designs?

No - BC817K-25W uses SOT323 (SC-70), while BC817-25 uses SOT23. Though electrically identical, the 2.2 × 2.2 mm SOT323 footprint is incompatible with SOT23 pads (2.9 × 1.3 mm). Mechanical redesign and requalification are required for substitution.