Nexperia USA Inc. BZX79-C51,143

Overview

BZX79-C51,143 from Nexperia is a ±5% tolerance Zener voltage regulator diode in a hermetically sealed SOD27 (DO-35) glass package, rated for 51 V nominal Zener voltage at 2 mA test current, 400–500 mW total power dissipation, and 40 W non-repetitive peak reverse power. It serves as a low-power voltage reference or stabilization element in power supply feedback loops, sensor biasing circuits, and overvoltage protection clamps.

For engineers reviewing the BZX79-C51,143 datasheet, BZX79-C51,143 pinout, BZX79-C51,143 application, or BZX79-C51,143 equivalent, this page delivers verified electrical parameters, thermal behavior, temperature coefficient, differential resistance, and real-world use context - all aligned with Nexperia's official 2002 product data sheet and post-NXP transition documentation.

Technical Context

This Zener diode operates in reverse breakdown mode with a specified nominal Zener voltage of 51 V at I_Ztest = 2 mA, exhibiting a typical differential resistance of 90 Ω and a positive temperature coefficient of +38.6 to +57.2 mV/K across its operating current range. Its junction-to-ambient thermal resistance is 380 K/W under standard PCB mounting conditions.

The device complies with IEC 60134 Absolute Maximum Ratings, supports non-repetitive surge pulses up to 100 μs at 40 W, and maintains stable regulation down to 0.7×V_Znom reverse bias while limiting leakage to ≤40 nA at that condition.

Key Specifications

Pinout & Package

Hermetically sealed axial-leaded SOD27 (DO-35) glass package with cathode indicated by a dark band on the body. Leads are tinned copper-clad steel, suitable for through-hole soldering. Package dimensions: D = 1.85 mm max, L = 25.4 mm min, b = 0.56 mm max, G1 = 4.25 mm max.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX79-B51,113, the BZX79-C51,143 trades voltage precision for lower cost and sufficient stability in non-critical biasing; versus 1N4733A, it offers smaller SOD27 footprint and better thermal performance on compact PCBs but lower absolute power handling.

Availability

BZX79-C51,143 is available at Aetrix Electronics and suitable for industrial sensor biasing, power supply feedback referencing, and overvoltage clamping requiring stable component supply across extended production lifecycles.

Supply support for BZX79-C51,143 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 leader in discrete, logic, and PowerMOS semiconductors, formed in 2017 from the former NXP Standard Products business, with focus on automotive, industrial, computing, and consumer markets.

The BZX79 series belongs to Nexperia's legacy Zener diode portfolio, engineered for reliable low-power voltage regulation and referencing in cost-sensitive, high-volume applications where hermetic stability and E24 voltage coverage are essential.

FAQ

What is the maximum continuous reverse current the BZX79-C51,143 can sustain at 51 V?

The device does not specify a maximum continuous reverse current independent of power dissipation. At 51 V, the absolute maximum continuous Zener current is limited by P_tot = 500 mW, yielding I_Zmax ≈ 9.8 mA at 51 V - assuming ambient temperature ≤50 °C and lead length ≤8 mm. Exceeding this risks thermal runaway due to junction temperature exceeding 200 °C.

Does the BZX79-C51,143 have a defined forward voltage drop, and how is it used in circuit design?

Yes - forward voltage is specified as ≤0.9 V at I_F = 10 mA. While primarily used in reverse breakdown, this parameter matters when the diode may experience forward conduction during startup, fault conditions, or AC-coupled signals. Designers use it to calculate forward power loss and ensure series resistors limit I_F to ≤250 mA.

How does the temperature coefficient affect regulation accuracy over –40 °C to +125 °C?

With a typical S_Z of +46.9 mV/K, the Zener voltage increases ~3.75 V across an 80 °C span (e.g., –40 °C to +125 °C). For a 51 V nominal device, this yields ~7.4% drift - acceptable for non-precision applications but requiring compensation in high-accuracy systems via resistor networks or digital calibration.

Can the BZX79-C51,143 replace the BZX79-C47,143 in a 48 V clamp circuit without redesign?

No - although both share the same ±5% tolerance and SOD27 package, their Zener voltages differ (47 V vs. 51 V). Substituting changes the clamping threshold by 4 V, potentially causing premature triggering or failure to protect. A full analysis of worst-case voltage margins, surge energy, and downstream component ratings is required before substitution.