Nexperia USA Inc. BZX79-B51,143

Overview

BZX79-B51,143 from Nexperia is a ±2% tolerance Zener voltage regulator diode with nominal 51 V breakdown voltage at 2 mA test current, 90 Ω typical differential resistance, and −38.6 mV/K temperature coefficient at I_Z = 2 mA. It operates in hermetically sealed SOD27 (DO-35) glass package, rated for 500 mW total power dissipation at T_amb = 50 °C, and serves as a precision low-power voltage reference in analog sensor signal conditioning circuits.

For engineers reviewing the BZX79-B51,143 datasheet, BZX79-B51,143 pinout, BZX79-B51,143 application, or BZX79-B51,143 equivalent, this page delivers verified electrical parameters, thermal behavior under surge conditions, junction-to-ambient thermal resistance (380 K/W), and validated alternative parts for voltage reference design in industrial control and power supply feedback loops.

Technical Context

This Zener diode functions as a two-terminal shunt voltage regulator, maintaining stable reverse-biased conduction above its specified V_Z threshold. Its operation relies on controlled avalanche breakdown in silicon, with differential resistance (90 Ω typ.) defining regulation stiffness and temperature coefficient (−38.6 mV/K) indicating negative drift with rising junction temperature.

The device exhibits non-repetitive peak reverse power dissipation of 40 W for 100 μs pulses at T_j = 25 °C, and junction-to-ambient thermal resistance of 380 K/W under standard PCB mounting (lead length ≤ 8 mm, no metallization pad). Capacitance is 40 pF at f = 1 MHz and V_R = 0 V.

Key Specifications

Pinout & Package

Hermetically sealed axial-leaded SOD27 (DO-35) glass package with cathode indicated by a band on the body. Dimensions: D = 4.25 mm max., L = 25.4 mm min., b = 0.56 mm max., G1 = 1.85 mm max.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX79-B51,143, the 1N4733A trades precision for cost and availability, while the BZX85C51 offers higher power handling at the expense of tighter tolerance and increased thermal mass-making the BZX79-B51,143 optimal for space-constrained, low-current, high-stability reference designs.

Availability

BZX79-B51,143 is available at Aetrix Electronics and suitable for industrial sensor interfaces, linear regulator feedback networks, overvoltage protection circuits, and calibration standards requiring stable component supply and consistent parametric performance across production batches.

Supply support for BZX79-B51,143 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, serving automotive, industrial, computing, consumer, and wearable markets with high-volume, high-reliability components.

The BZX79 series belongs to Nexperia's precision Zener voltage regulator portfolio, engineered for low-power stabilization and referencing in analog signal chains where accuracy, thermal predictability, and long-term stability are critical.

FAQ

What is the maximum continuous reverse current the BZX79-B51,143 can sustain without degradation?

The device does not specify a maximum continuous reverse current; instead, it is limited by power dissipation. At T_amb = 50 °C, P_tot = 500 mW implies I_Z ≤ 9.8 mA (500 mW ÷ 51 V) for safe DC operation. Exceeding this risks junction overheating beyond 200 °C, triggering permanent parameter shift or failure.

How does the −38.6 mV/K temperature coefficient affect output voltage in a 0 °C to 70 °C operating range?

Over a 70 K span, the voltage shift is −38.6 mV/K × 70 K = −2.7 V, resulting in a V_Z range of ~47.3 V to 50.0 V. This drift must be accommodated in system-level accuracy budgets or compensated using matched components or lookup-table correction in digital systems.

Can the BZX79-B51,143 be used in series or parallel configurations for higher voltage or current capability?

Series connection is discouraged due to mismatched temperature coefficients causing unequal voltage sharing and thermal runaway. Parallel use is invalid-Zener dynamic resistance variations lead to current hogging. For higher voltage, select a single higher-V_Z part; for higher current, use an active buffer or series-pass transistor with this diode as reference.

Is the SOD27 package compatible with automated through-hole assembly processes?

Yes-the SOD27 (DO-35) package has standardized axial leads with 25.4 mm minimum length and 0.56 mm max. diameter, meeting IPC-7351B land pattern guidelines for wave soldering and selective soldering. Lead spacing and coplanarity support reliable insertion and wetting in high-yield manufacturing lines.