Nexperia USA Inc. BZX84W-B13-QX

Overview

BZX84W-B13-QX from Nexperia is a ±2% tolerance Zener voltage regulator diode in SOT323 (SC-70) package, rated for 13 V nominal regulation at 5 mA, with 170 Ω differential resistance, 9.4 mV/K temperature coefficient, and 2.5 pF capacitance at 1 MHz. It delivers stable reference voltage in automotive power supply rails and low-power sensor biasing circuits.

For engineers reviewing the BZX84W-B13-QX datasheet, BZX84W-B13-QX pinout, BZX84W-B13-QX application, or BZX84W-B13-QX equivalent, key selection criteria include Zener voltage tolerance, thermal coefficient stability over temperature, junction-to-ambient thermal resistance, and AEC-Q101 qualification status for automotive deployment.

Technical Context

This device operates as a two-terminal shunt voltage reference, maintaining regulated output by conducting reverse current above its specified Zener breakdown voltage of 12.7–13.3 V at 5 mA. Its 9.4 mV/K temperature coefficient ensures predictable drift behavior across −55 °C to +150 °C ambient range.

The SOT323 package enables high-density PCB layout while delivering 275 mW total power dissipation on FR4 board with single-sided copper. With 100 nA reverse leakage at 8 V and 170 Ω dynamic impedance, it supports precision regulation in low-current analog subsystems.

Key Specifications

Pinout & Package

SOT323 (SC-70) leadless surface-mount plastic package with 3 terminals; compact 2.2 mm × 1.35 mm footprint optimized for space-constrained automotive and portable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84W-B13-QX, the C13-Q offers lower cost but reduced voltage accuracy, while MMSZ4688T1G provides greater power headroom at the expense of automotive qualification and board space-making the B-series the optimal choice for AEC-compliant 13 V reference designs demanding precision and compactness.

Availability

BZX84W-B13-QX is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor transmitters, portable medical diagnostics, and smart home safety devices requiring stable component supply with guaranteed AEC-Q101 compliance.

Supply support for BZX84W-B13-QX 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-certified Zener diode portfolio, engineered specifically for stable voltage reference and overvoltage protection in harsh-environment automotive and industrial control systems.

FAQ

What is the maximum continuous reverse current this Zener can handle at 13 V?

The BZX84W-B13-QX has a maximum total power dissipation of 275 mW at 25 °C ambient on a standard FR4 PCB. At its nominal 13 V Zener voltage, this corresponds to a maximum continuous reverse current of approximately 21 mA (275 mW ÷ 13 V). Exceeding this value risks thermal runaway unless board-level cooling is enhanced.

Does this part require derating above 25 °C ambient temperature?

Yes. With a junction-to-ambient thermal resistance of 455 K/W, the device must be derated linearly above 25 °C. For every 1 °C rise in ambient temperature, the allowable power decreases by 0.605 mW (275 mW ÷ 455 K). At 85 °C ambient, maximum dissipation drops to ~135 mW, limiting usable reverse current to ~10.4 mA at 13 V.

Can Pin 2 (n.c.) be used as a mechanical ground or thermal pad?

No. Pin 2 is internally not connected and electrically isolated. Using it as a thermal pad or ground connection violates the SOT323 mechanical specification and may cause solder joint cracking or internal die stress. The datasheet explicitly requires Pin 2 to remain unconnected on the PCB layout.

How does the +9.4 mV/K temperature coefficient affect regulation accuracy over −40 °C to +125 °C?

Over a 165 K temperature span, the coefficient contributes ±1.55 V drift (9.4 mV/K × 165 K) relative to the 25 °C nominal 13 V. Combined with ±2 % initial tolerance (±0.26 V), total worst-case variation is ±1.81 V - meaning output ranges from 11.19 V to 14.81 V across temperature. This is acceptable for non-precision biasing but requires compensation in metrology-grade applications.