Nexperia USA Inc. BZX84W-B56F

Overview

BZX84W-B56F from Nexperia is a ±2 % tolerance Zener voltage regulator diode rated at 56 V nominal working voltage, 275 mW total power dissipation, and 455 K/W junction-to-ambient thermal resistance in SOT323 (SC-70) package; used for precision voltage reference and overvoltage protection in compact DC power rails.

For engineers reviewing the BZX84W-B56F datasheet, BZX84W-B56F pinout, BZX84W-B56F application, or BZX84W-B56F equivalent, key selection criteria include Zener voltage tolerance (±2 %), low differential resistance (425 Ω at I_Z = 2 mA), temperature coefficient (+57.0 mV/K), reverse leakage current (50 nA at V_R = 39.2 V), and SOT323 footprint compatibility with high-density PCB layouts.

Technical Context

This Zener diode operates in reverse breakdown mode to maintain stable 56 V regulation across load and line variations, with a typical differential resistance of 425 Ω at 2 mA test current ensuring minimal voltage deviation under dynamic current changes.

Its positive temperature coefficient of +57.0 mV/K enables predictable drift behavior in temperature-varying environments, and its 50 nA reverse leakage at 70 % of nominal Zener voltage supports low-power standby circuit integrity.

Key Specifications

Pinout & Package

SOT323 (SC-70) leadless surface-mount plastic package: 1.35 mm × 1.75 mm footprint, 0.65 mm pitch, 0.9 mm max height; optimized for automated reflow assembly and space-constrained designs.

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-B56F delivers tighter voltage control (±2 % vs. ±5 %), lower dynamic impedance (425 Ω vs. ≥700 Ω), and significantly lower leakage (50 nA vs. ≥500 nA), making it optimal for precision reference and low-quiescent-power applications.

Availability

BZX84W-B56F is available at Aetrix Electronics and suitable for power supply reference, overvoltage clamp, and low-power sensor bias applications requiring stable component supply, consistent parametric performance, and long-term SMT production continuity.

Supply support for BZX84W-B56F 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 and industrial-grade components.

The BZX84W series belongs to Nexperia's general-purpose Zener diode product line, engineered for stable voltage regulation and transient suppression in space-constrained, cost-sensitive consumer, industrial, and telecom applications.

FAQ

What is the maximum continuous reverse current the BZX84W-B56F can sustain without degradation?

The device supports a maximum continuous forward current of 200 mA, but for Zener operation, sustained reverse current must be limited by power dissipation. At 25 °C ambient on a standard FR4 PCB, the 275 mW rating allows up to ~4.9 mA average reverse current (275 mW ÷ 56 V) before thermal derating applies. Exceeding this requires active cooling or reduced ambient temperature.

Does the 'n.c.' pin (Pin 2) require grounding or isolation on the PCB?

Pin 2 is internally not connected and must remain electrically floating-no trace, pad, or solder mask opening is required. Connecting it to ground or any net risks mechanical stress on the die bond wire or unintended parasitic coupling; Nexperia's recommended footprint (Fig. 9) omits copper at Pin 2 location.

How does the +57.0 mV/K temperature coefficient affect regulation accuracy over −40 °C to +125 °C?

Across that range, the Zener voltage shifts by approximately +4.8 V (57.0 mV/K × 85 K), resulting in a final value near 60.8 V at +125 °C. This predictable drift enables first-order compensation in feedback networks; for example, pairing with a negative-TC resistor network can reduce net drift to <±0.5 % over the full range.

Can BZX84W-B56F replace older BZX84-B56 in existing SOT23 designs?

No-it uses SOT323 (SC-70), which has smaller dimensions (1.35 mm × 1.75 mm) and 0.65 mm pitch versus SOT23's 2.9 mm × 1.3 mm and 0.95 mm pitch. Footprint, stencil aperture, and placement accuracy must be updated; electrical parameters differ slightly (e.g., lower P_tot, tighter tolerance), requiring validation in the target circuit.