Nexperia USA Inc. BZX84W-B56-QF

Overview

BZX84W-B56-QF from Nexperia is a ±2% tolerance Zener voltage regulator diode with 56 V nominal breakdown voltage, 425 Ω typical differential resistance at I_Z = 2 mA, and AEC-Q101 qualification for automotive use. It operates in SOT323 (SC-70) package, delivers 275 mW total power dissipation on FR4 PCB, and maintains stable regulation in high-frequency power supply feedback loops.

For engineers reviewing the BZX84W-B56-QF datasheet, BZX84W-B56-QF pinout, BZX84W-B56-QF application, or BZX84W-B56-QF equivalent, this page provides verified Zener voltage, thermal resistance, reverse leakage, temperature coefficient, and automotive qualification status - critical for precision voltage reference and overvoltage protection design in harsh-environment electronics.

Technical Context

This Zener diode functions as a two-terminal shunt voltage reference, clamping reverse-biased voltage at 56 V ±2% under 2 mA test current. Its 57.0 mV/K temperature coefficient ensures predictable drift across −55 °C to +150 °C ambient range, and its 0.3 pF capacitance at 1 MHz supports high-frequency noise suppression.

Designed for surface-mount reflow assembly on standard FR4 PCBs, it exhibits 455 K/W junction-to-ambient thermal resistance and withstands non-repetitive 40 W surge pulses (100 µs), enabling robust transient voltage suppression in automotive ECUs and industrial power rails.

Key Specifications

Pinout & Package

SOT323 (SC-70) leadless surface-mount plastic package: 1.3 mm × 1.75 mm footprint, 0.95 mm height, tin-plated terminations compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener regulation applications.

Compared with MMBZ5256B and BZX84-C56, BZX84W-B56-QF offers tighter ±2% tolerance, lower 425 Ω differential resistance, higher 275 mW power rating, and guaranteed AEC-Q101 compliance - making it optimal for next-generation automotive voltage references where accuracy and reliability are non-negotiable.

Availability

BZX84W-B56-QF is available at Aetrix Electronics and suitable for automotive engine control units, industrial programmable logic controllers, and medical infusion pump power monitoring systems requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for BZX84W-B56-QF 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 high-volume, high-reliability discrete and logic devices, with leadership in automotive-qualified components and energy-efficient solutions.

The BZX84W-Q series belongs to Nexperia's AEC-Q101-qualified Zener diode product line, engineered specifically for precision voltage regulation and transient suppression in automotive power systems and industrial control interfaces.

FAQ

What is the maximum continuous reverse current the BZX84W-B56-QF can handle at 25 °C?

The device has no specified maximum continuous reverse current; instead, its safe operating limit is defined by total power dissipation. At 25 °C ambient on FR4 PCB, it supports up to 275 mW, corresponding to ~4.9 mA at 56 V (P = V × I). Exceeding this requires thermal derating per the 455 K/W R_th(j-a) value.

Does the 'QF' suffix indicate a specific packaging or testing variant?

Yes - the 'QF' suffix denotes Nexperia's automotive-grade qualification variant: full AEC-Q101 stress testing, extended temperature screening (−55 °C to +150 °C), and enhanced traceability per PPAP Level 3 documentation. It is distinct from commercial 'Q' versions lacking automotive validation.

Can BZX84W-B56-QF replace BZX84-C56 in existing designs without layout changes?

Yes - both use identical SOT323 (SC-70) package and pinout (Anode–n.c.–Cathode). However, BZX84W-B56-QF offers ±2% tolerance vs. ±5%, 425 Ω vs. 500 Ω r_dif, and 275 mW vs. 225 mW P_tot, enabling improved regulation accuracy and thermal headroom without PCB modification.

How does the 2nd pin (n.c.) affect PCB layout and thermal performance?

Pin 2 is internally unconnected and must remain unattached on the PCB. Leaving it floating avoids unintended coupling; connecting it risks parasitic capacitance increase or solder bridging. Its presence does not contribute to thermal conduction - heat flows only through pins 1 and 3 and the exposed die pad area beneath the package body.