Infineon Technologies BC857CWE6433HTMA1

Overview

BC857CWE6433HTMA1 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 = 420–520 at I_C = 2 mA), low V_CE(sat) (≤300 mV at I_C = 10 mA/I_B = 0.5 mA), and low noise (F = 1–4 dB at 1 kHz), making it suitable for low-distortion preamplifier and switching applications in automotive and industrial control modules.

For engineers reviewing the BC857CWE6433HTMA1 datasheet, BC857CWE6433HTMA1 pinout, BC857CWE6433HTMA1 application, or BC857CWE6433HTMA1 equivalent, key selection criteria include verified h_FE group C performance, SOT323 package thermal resistance (R_thJS ≤ 90 K/W), AEC-Q101 qualification, and complementary NPN pairing with BC847C.

Technical Context

This PNP transistor operates in linear amplification and saturated switching modes, with guaranteed h_FE grouping (C: 420–520 at I_C = 10 µA/V_CE = 5 V) and stable gain across I_C = 0.2–100 mA. Its f_T of 250 MHz supports wideband AF signal handling up to 15 kHz with minimal phase shift.

The device features low capacitance (C_cb = 1.5 pF, C_eb = 8 pF) and low V_BE(sat) (700–850 mV), enabling fast turn-on/turn-off in discrete driver stages while maintaining <1% THD in Class-A audio biasing configurations.

Key Specifications

Pinout & Package

BC857CWE6433HTMA1 is housed in a RoHS-compliant SOT323 (SC-70) plastic surface-mount package, measuring 2.1 × 1.25 × 0.95 mm, optimized for high-density PCB assembly and automated reflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC857C,115 and MMBT857LT1G, BC857CWE6433HTMA1 offers superior thermal performance (R_thJS ≤ 90 K/W) and automotive-grade reliability, making it optimal for space-constrained, high-reliability driver and preamp designs where consistent h_FE and low noise are critical.

Availability

BC857CWE6433HTMA1 is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor interfaces, and consumer audio input stages requiring stable component supply and long-term lifecycle support.

Supply support for BC857CWE6433HTMA1 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 ICs, and discrete devices, with global manufacturing and quality certifications.

The BC856–BC860 family was engineered for high-reliability, low-noise AF amplification and switching in automotive and industrial environments, emphasizing gain consistency, thermal robustness, and AEC-Q101 compliance.

FAQ

Is BC857CWE6433HTMA1 pin-compatible with BC847C?

No - BC857CWE6433HTMA1 is a PNP transistor with Base-Emitter-Collector pinout (1-2-3), while BC847C is an NPN with Emitter-Base-Collector (1-2-3). They are complementary types, not pin-compatible. Direct replacement requires circuit topology revision, including polarity reversal of biasing and load connections.

What is the maximum continuous collector current at 85°C ambient?

At T_A = 85°C, derating from the 100 mA I_C rating applies. With R_thJA ≈ 300 K/W (typical for SOT323 on 2-layer board), junction temperature reaches 150°C limit at ~65 mA. For reliable 85°C operation, limit I_C to 50 mA with adequate copper pour and airflow.

Does this part support pulsed operation beyond its DC ratings?

Yes - pulse testing (t_p < 300 µs, duty cycle < 2%) allows peak I_C up to 200 mA and P_tot up to 300 mW. The permissible pulse load curve (Fig. EHP00377) shows P_tot(max)/P_tot(DC) = 3.5 at t_p = 10 µs, enabling short-duration surge handling in motor commutation or ESD clamp circuits.

How does the h_FE variation affect bias stability in a common-emitter amplifier?

With h_FE ranging 420–520 (group C), emitter degeneration (R_E ≥ 100 Ω) is essential to stabilize Q-point. Simulations show <5% I_C shift across h_FE extremes when R_E = 220 Ω and V_CC = 5 V, ensuring predictable gain and thermal runaway immunity in production units.