Nexperia USA Inc. BZX84W-B10X

Overview

BZX84W-B10X from Nexperia is a ±2 % tolerance Zener voltage regulator diode in SOT323 (SC-70) package, rated for 10 V nominal Zener voltage at 5 mA, 275 mW total power dissipation, and 150 °C maximum junction temperature. It provides stable reference voltage in low-power analog circuits, voltage clamping in signal conditioning stages, and overvoltage protection in microcontroller I/O interfaces.

For engineers reviewing the BZX84W-B10X datasheet, BZX84W-B10X pinout, BZX84W-B10X application, or BZX84W-B10X equivalent, key selection criteria include Zener voltage tolerance (±2 %), differential resistance (150 Ω at 5 mA), temperature coefficient (+6.4 mV/K), reverse leakage current (200 nA at 7 V), and thermal resistance (455 K/W).

Technical Context

This device operates as a two-terminal shunt voltage regulator, maintaining a stable 10 V output across its cathode-anode terminals when reverse-biased above its breakdown threshold. Its ±2 % tolerance ensures tight regulation for precision reference applications, while its 150 Ω dynamic impedance at 5 mA supports stable load regulation under moderate current variation.

The BZX84W-B10X exhibits a positive temperature coefficient of +6.4 mV/K at 5 mA, enabling predictable drift compensation in temperature-sensitive designs. Its 275 mW power rating is defined with FR4 PCB mounting (single-sided copper, tin-plated, standard footprint), and it withstands non-repetitive peak reverse power up to 40 W for 100 µs pulses.

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 high-density PCB layouts and reflow/wave soldering per Figures 9–10 in the datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84W-C10, the BZX84W-B10X delivers tighter voltage control at identical thermal and packaging constraints; versus MMSZ4689, it trades higher power capacity for smaller size and lower thermal resistance on FR4, making it preferable for miniaturized, thermally constrained designs.

Availability

BZX84W-B10X is available at Aetrix Electronics and suitable for voltage reference generation, signal clamping, overvoltage protection, and bias current sourcing requiring stable component supply across industrial automation, IoT sensor nodes, and portable electronics.

Supply support for BZX84W-B10X 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 logic, discrete, and MOSFET devices, serving automotive, industrial, and consumer markets with scalable manufacturing and rigorous quality systems.

The BZX84W series belongs to Nexperia's general-purpose Zener diode product line, engineered for stable voltage regulation in space-constrained SMT applications where precision, thermal robustness, and manufacturability are critical.

FAQ

What is the maximum continuous reverse current the BZX84W-B10X can handle at 25 °C?

The BZX84W-B10X supports a maximum forward current of 200 mA, but as a Zener diode operating in reverse breakdown, its continuous reverse current is limited by power dissipation. At 25 °C ambient and 10 V Zener voltage, the maximum sustainable reverse current is 27.5 mA (275 mW ÷ 10 V), assuming no additional thermal derating from PCB layout or ambient rise.

How does the "B" suffix in BZX84W-B10X differ from "C" in BZX84W-C10?

The "B" suffix denotes ±2 % Zener voltage tolerance (9.80 V–10.20 V), while "C" indicates ±5 % tolerance (9.40 V–10.60 V). Both share identical package (SOT323), power rating (275 mW), and thermal characteristics, but the "B" grade provides tighter regulation for precision reference applications where system-level calibration is impractical.

Can BZX84W-B10X be used in high-frequency signal clamping applications?

Yes - its typical junction capacitance is 3 pF at 0 V reverse bias (1 MHz), enabling effective clamping up to ~100 MHz with minimal signal distortion. The low capacitance, combined with fast response to transients (<10 ns turn-on), makes it suitable for RF front-end protection and high-speed digital I/O line clamping where parasitic loading must be minimized.

Is the not-connected (n.c.) pin in the SOT323 package electrically isolated or thermally coupled?

Pin 2 is electrically isolated with no internal connection, confirmed by the simplified outline and pinning table. However, as a metalized pad in the SOT323 package, it contributes to overall thermal conduction from the die to the PCB; Nexperia's thermal characterization assumes standard footprint mounting, so leaving it unconnected does not impair thermal performance under specified test conditions.