Infineon Technologies BC 857BF E6327

Overview

BC857BF E6327 from Infineon Technologies is a PNP silicon small-signal transistor designed for audio-frequency input stages and driver circuits. It delivers high DC current gain (h_FE = 220–480 at I_C = 2 mA), low V_CE(sat) (max 300 mV at I_C = 10 mA/I_B = 0.5 mA), and low noise (1 dB typical at 1 kHz, 0.2 mA). It is AEC-Q101 qualified and RoHS-compliant in TSFP-3 package.

For engineers reviewing the BC857BF E6327 datasheet, BC857BF E6327 pinout, BC857BF E6327 application, or BC857BF E6327 equivalent, key selection criteria include its PNP polarity, 45 V V_CEO, 100 mA I_C, thermal resistance (R_thJS ≤ 90 K/W), and suitability for automotive-grade analog signal conditioning and discrete biasing networks.

Technical Context

The BC857BF E6327 operates as a linear PNP bipolar junction transistor with fixed emitter-base and collector-base junctions optimized for stable DC amplification and switching in low-power analog paths. Its h_FE grouping (B) ensures predictable gain spread across production lots, and its f_T of 250 MHz supports bandwidth-critical AF and low-speed digital interface applications.

Thermal design is constrained by its TSFP-3 package's R_thJS ≤ 90 K/W and P_tot = 250 mW at T_S ≤ 128 °C. The device exhibits low C_cb (1.5 pF typ) and C_eb (8 pF typ), enabling minimal Miller effect in common-emitter configurations up to 100 kHz.

Key Specifications

Pinout & Package

BC857BF E6327 is housed in a leadless, surface-mount TSFP-3 (Thin Small Outline Transistor, Flat Lead) package measuring 1.7 × 1.3 × 0.5 mm, optimized for high-density automotive PCBs and thermally demanding environments.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP small-signal transistor applications.

Compared with BC857B,215 and MMBT857LT1G, BC857BF E6327 offers superior thermal resistance (≤90 K/W), guaranteed low-noise performance, and full AEC-Q101 validation-making it the only option for thermally dense, safety-critical automotive and industrial control applications requiring long-term parametric stability.

Availability

BC857BF E6327 is available at Aetrix Electronics and suitable for automotive interior lighting control, industrial sensor signal conditioning, consumer audio pre-amplifier stages, and medical wearable biopotential front-end designs requiring stable component supply and long-lifecycle support.

Supply support for BC857BF 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 BC857BF belongs to Infineon's BC856–BC860 family of AEC-Q101-qualified PNP transistors engineered for robust, low-noise analog signal handling in harsh automotive and industrial environments.

FAQ

Is BC857BF E6327 pin-compatible with standard SOT-23 PNP transistors?

No. BC857BF E6327 uses the TSFP-3 package (1.7 × 1.3 mm), which has different pad layout and thermal pad geometry than standard SOT-23. Pin numbering matches (1=Base, 2=Emitter, 3=Collector), but solder footprint and thermal relief must be redesigned per Infineon's TSFP-3 land pattern guidelines.

What is the maximum allowable junction temperature during pulsed operation?

The absolute maximum junction temperature remains 150 °C regardless of pulse duration. For pulsed conditions, peak power must stay within the permissible pulse load curve (EHP00377), where P_tot(max)/P_tot(DC) ≤ 10 at t_p = 10 µs (D = 0.005), decreasing to ≤ 2.5 at t_p = 10 ms (D = 0.02).

Does BC857BF E6327 support operation at –55 °C?

Yes. While storage temperature extends to –65 °C, the device is fully characterized and functional down to –40 °C per AEC-Q101. Operation at –55 °C is possible but requires derating V_CEO and h_FE based on the published I_CBO vs. T_A curve (EHP00381) and consultation with Infineon's reliability team.

How does the TSFP-3 package improve thermal performance over SOT-23?

TSFP-3 features an exposed thermal pad on the bottom side that enables direct thermal coupling to inner PCB copper layers. This achieves R_thJS ≤ 90 K/W-nearly 3× better than standard SOT-23's ~240 K/W-allowing 250 mW continuous dissipation at board temperatures up to 128 °C without external heatsinking.