Nexperia USA Inc. BZX79-B12,143

Overview

BZX79-B12,143 from Nexperia is a ±2% tolerance Zener voltage regulator diode with nominal 12 V breakdown voltage at 5 mA test current, 50 Ω typical differential resistance, and −65 °C to +200 °C junction temperature range, housed in hermetically sealed SOD27 (DO-35) glass package for low-power voltage reference and stabilization in linear power supplies and sensor biasing circuits.

For engineers reviewing the BZX79-B12,143 datasheet, BZX79-B12,143 pinout, BZX79-B12,143 application, or BZX79-B12,143 equivalent, key selection criteria include Zener voltage tolerance (±2%), thermal resistance (380 K/W), non-repetitive peak reverse power (40 W), and reverse leakage (100 nA at 8 V) under defined test conditions.

Technical Context

This discrete Zener diode operates in reverse-biased breakdown mode to maintain stable voltage across load terminals. Its 12 V nominal Zener voltage is specified at I_Ztest = 5 mA, with temperature coefficient of +6.0 mV/K and typical differential resistance of 50 Ω - enabling predictable regulation in low-current reference paths.

The device uses axial-leaded hermetic glass construction (SOD27/DO-35) with cathode band marking, supporting operation up to 200 °C junction temperature and meeting IEC 60134 absolute maximum ratings. It delivers 400 mW total power dissipation at T_amb = 50 °C with no PCB metallization pad.

Key Specifications

Pinout & Package

Hermetically sealed axial-leaded SOD27 (DO-35) glass package with cathode identified by a colored band; leads are tinned copper alloy, suitable for through-hole soldering on FR-4 PCBs.

Key Features

Applications

Availability

BZX79-B12,143 is available at Aetrix Electronics and suitable for linear power supply references, sensor biasing circuits, overvoltage protection clamps, and microcontroller reset circuits requiring stable component supply with traceable sourcing and long-term lifecycle support.

Supply support for BZX79-B12,143 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 semiconductors, formed in 2017 from the former NXP Standard Products division, specializing in high-volume, high-reliability components for automotive, industrial, and consumer markets.

BZX79-B12,143 belongs to the BZX79 series of low-power Zener diodes designed specifically for precision voltage regulation and reference applications in cost-sensitive, space-constrained designs.

FAQ

What is the maximum continuous power dissipation for BZX79-B12,143 at 50 °C ambient?

The maximum continuous total power dissipation is 500 mW when mounted on a PCB with 8 mm lead length and tie-point temperature ≤50 °C, per IEC 60134 limiting values. Derating applies above 50 °C ambient per the R_{th j-a} = 380 K/W thermal resistance specification.

How does the temperature coefficient affect regulation accuracy over temperature?

At 12 V nominal, the BZX79-B12 exhibits a typical temperature coefficient of +6.0 mV/K. Over a −40 °C to +125 °C junction range, this introduces up to ±0.99 V drift, requiring compensation in high-accuracy references or limiting use to narrow-temperature applications.

Can BZX79-B12,143 be used as a replacement for BZX79-C12?

No - BZX79-C12 has approx. ±5% tolerance (11.4–12.7 V), while BZX79-B12,143 offers tighter ±2% (11.8–12.2 V). Substitution may cause out-of-spec reference voltage in precision circuits, though it is electrically compatible in non-critical clamping roles.

What is the reverse leakage current specification at 8 V?

The maximum reverse leakage current is 100 nA at V_R = 8 V and T_j = 25 °C, as specified in the Electrical Characteristics table. This low leakage supports ultra-low-power applications such as battery-backed sensor references.