Nexperia USA Inc. BC857AQC-QZ

Overview

BC857AQC-Q from Nexperia is a PNP general-purpose transistor in a DFN1412D-3 (SOT8009) leadless package, rated for −45 V V_CEO, −100 mA I_C, and DC current gain (h_FE) of 125–250 at V_CE = −5 V and I_C = −2 mA. It serves as a compact, AEC-Q101-qualified switching or amplification device in space-constrained automotive and industrial PCBs.

For engineers reviewing the BC857AQC-Q datasheet, BC857AQC-Q pinout, BC857AQC-Q application, or BC857AQC-Q equivalent, this part supports AOI-compatible solder joint inspection, operates up to 150 °C junction temperature, and delivers low saturation voltage (V_CEsat ≤ −650 mV at I_C = −100 mA / I_B = −5 mA), making it suitable for high-density, thermally demanding signal control circuits.

Technical Context

This PNP bipolar junction transistor features side-wettable flanks for automated optical inspection and is optimized for stable DC amplification and switching in low-power analog and digital interface stages. Its thermal resistance R_th(j-a) is 348 K/W on standard FR4 (35 µm Cu), enabling reliable operation under ambient temperatures from −55 °C to 150 °C.

The device exhibits V_BE ≈ −700 mV at I_C = −10 mA / I_B = −0.5 mA, with base-emitter saturation voltage (V_BEsat) ≤ −850 mV under heavy drive, and transition frequency f_T = 100 MHz at V_CE = −5 V / I_C = −10 mA - confirming suitability for audio-frequency and low-speed digital switching applications.

Key Specifications

Pinout & Package

DFN1412D-3 (SOT8009) is a 3-terminal, leadless surface-mount package with side-wettable flanks, measuring 1.4 mm × 1.2 mm × 0.48 mm and featuring a 0.8 mm pitch. Its low profile (0.5 mm max height) and exposed thermal pad enable efficient PCB heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC857BQC-Q and BC857CQC-Q, the BC857AQC-Q offers the lowest h_FE bin in the series - delivering superior consistency in temperature-sensitive bias networks and reduced risk of unintended saturation in marginally driven digital interfaces.

Availability

BC857AQC-Q is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor signal chains, and space-constrained IoT edge devices requiring stable component supply and AEC-Q101 compliance.

Supply support for BC857AQC-Q 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 efficiency technologies, delivering high-performance, reliable discrete and logic devices for automotive, industrial, and consumer markets.

The BC857xQC-Q series belongs to Nexperia's AEC-Q101-qualified general-purpose transistor portfolio, engineered specifically for robust, miniaturized switching and amplification in harsh-environment automotive and industrial control systems.

FAQ

Is BC857AQC-Q pin-compatible with BC847AQC-Q?

No - BC857AQC-Q is a PNP transistor while BC847AQC-Q is its NPN complement. They share identical DFN1412D-3 package and pinout (B-E-C), but polarity reversal means direct substitution would invert circuit behavior. Use only as functional complements in push-pull or complementary pair designs, not drop-in replacements.

What is the maximum allowable PCB copper thickness for thermal performance validation?

Nexperia specifies two thermal test conditions: 35 µm and 70 µm copper on FR4. The 70 µm case yields lower R_th(j-a) (278 K/W vs. 348 K/W) and higher P_tot (450 mW). For production designs, use 70 µm copper with standard footprint per Figure 17 to achieve rated power dissipation and junction temperature margin.

Does BC857AQC-Q support reflow soldering with lead-free profiles?

Yes - the DFN1412D-3 package is qualified for standard lead-free reflow (J-STD-020, peak 260 °C). Nexperia provides detailed footprint and stencil recommendations (0.1 mm thickness, 0.45 mm solder paste openings) in Figure 17. Side-wettable flanks ensure reliable solder fillet formation visible to AOI systems without requiring post-solder X-ray.

How does h_FE variation affect bias stability over temperature?

h_FE decreases by ~0.5%/°C above 25 °C and increases below it, with BC857AQC-Q maintaining ≥80% of nominal gain between −55 °C and +125 °C. At I_C = −2 mA, h_FE remains within 125–250 across this range, enabling stable bias in automotive cabin modules without active compensation.