Nexperia USA Inc. BZX84J-C51,115

Overview

BZX84J-C51,115 from Nexperia is a ±5 % tolerance Zener voltage regulator diode with nominal 51 V working voltage, 350 mW total power dissipation, and AEC-Q101 qualification for automotive use in SOD323F (SC-90) surface-mount package. It provides stable reverse-biased voltage reference in low-power supply regulation and overvoltage protection circuits.

For engineers reviewing the BZX84J-C51,115 datasheet, BZX84J-C51,115 pinout, BZX84J-C51,115 application, or BZX84J-C51,115 equivalent, this device serves as a precision 51 V voltage clamp with low differential resistance (rdiff = 350 Ω at IZ = 2 mA), temperature coefficient of +57.2 mV/K, and non-repetitive peak reverse current of 0.4 A under 100 µs surge conditions.

Technical Context

This Zener diode operates in reverse breakdown mode to maintain a stable 51 V reference across its terminals when reverse-biased above its nominal Zener voltage. Its junction temperature range spans −55 °C to +150 °C, supporting operation in harsh automotive environments.

It exhibits a positive temperature coefficient (+57.2 mV/K at IZ = 2 mA), indicating voltage increases with temperature - critical for thermal drift compensation in feedback networks. The device uses silicon planar technology with cathode-anode polarity defined by a marking bar on the SOD323F package.

Key Specifications

Pinout & Package

The BZX84J-C51,115 is housed in a SOD323F (SC-90) plastic surface-mount package measuring 2.7 mm × 1.35 mm × 0.95 mm, with flat leads optimized for reflow soldering on high-density PCBs. The cathode is marked by a visible bar on the package body.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84J-C51,115, the BZX84-C51,115 offers identical voltage rating but reduced power and reliability assurance, while MMSZ5257B-TP trades smaller size for higher thermal resistance and missing automotive qualification - making the BZX84J-C51,115 the sole option meeting AEC-Q101, 550 mW, and SOD323F constraints simultaneously.

Availability

BZX84J-C51,115 is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC input protection, DC-DC converter feedback references, and medical equipment overvoltage monitors requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for BZX84J-C51,115 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 specializing in high-performance, reliable discrete, logic, and MOSFET devices, with leadership in automotive-qualified components and energy-efficient solutions.

The BZX84J series belongs to Nexperia's AEC-Q101-qualified Zener diode product line, engineered specifically for robust voltage regulation and transient suppression in automotive and industrial power systems demanding high reliability under thermal and electrical stress.

FAQ

What is the maximum continuous power dissipation for BZX84J-C51,115 at 70 °C ambient?

At Tamb = 70 °C, the device's total power dissipation must be derated linearly from 550 mW at 25 °C using Rth(j-a) = 230 K/W. This yields a maximum Ptot of approximately 340 mW to maintain Tj ≤ 150 °C, calculated as (150 − 70) °C × (1/230 K/W) = 0.348 W. Operation beyond this risks thermal runaway.

How does the +57.2 mV/K temperature coefficient affect regulation accuracy over −40 °C to +125 °C?

Over that 165 K range, the Zener voltage shifts by +57.2 mV/K × 165 K = +9.44 V - resulting in a total VZ span of 48.0 V to 57.4 V. Designers must account for this ±9.2 % variation in feedback networks or pair with complementary TC components to achieve net-zero drift.

Can BZX84J-C51,115 replace BZX84-C51 in an existing design?

Yes, electrically - both share identical 51 V nominal voltage, ±5 % tolerance, and SOD323F package. However, BZX84J-C51,115 adds AEC-Q101 qualification and 550 mW Ptot versus 300 mW for BZX84-C51. No layout change is needed, but automotive applications require the J-series' enhanced reliability validation.

What is the recommended PCB pad layout for optimal thermal performance?

The datasheet specifies a 1 cm² tin-plated copper pad for the cathode on FR4. For best results, use a solid thermal pad connected to internal ground planes via ≥4 thermal vias (0.3 mm diameter), avoid solder mask over the pad, and maintain ≥0.2 mm clearance to adjacent traces to minimize thermal coupling and ensure Rth(j-a) ≤ 230 K/W.