Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Discrete Semiconductor Products > Diodes > Zener > Single Zener Diodes

Nexperia USA Inc. BZX79-B39,143

Name: BZX79-B39,143
Brand: Nexperia USA Inc.
SKU: BZX79-B39,143
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: BZX79-B39,143

Manufacturer:: Nexperia USA Inc.

Category:: Single Zener Diodes

Package:: DO-204AH, DO-35, Axial

Datasheet:: BZX79-B39,143.pdf

Description:: DIODE ZENER 39V 400MW ALF2

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:8,473

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

BZX79-B39,143 from Nexperia is a ±2% tolerance Zener voltage regulator diode with nominal working voltage of 39 V at 2 mA test current, 80 Ω typical differential resistance, and −28.7 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 power supply feedback paths.

For engineers reviewing the BZX79-B39,143 datasheet, BZX79-B39,143 pinout, BZX79-B39,143 application, or BZX79-B39,143 equivalent, this part is selected for stable 39 V regulation in space-constrained linear regulators, sensor biasing circuits, and overvoltage protection clamps where ±2% initial tolerance and predictable thermal drift are critical.

Technical Context

This Zener diode functions in reverse-bias breakdown mode, delivering stable DC reference voltage under controlled current conditions. Its 39 V nominal Zener voltage is specified at I_Ztest = 2 mA, with 80 Ω typical differential resistance ensuring minimal output voltage variation across load current changes.

The device exhibits a negative temperature coefficient of −28.7 mV/K at I_Z = 2 mA, indicating predictable voltage decrease with rising junction temperature - a key parameter for thermal compensation design in precision references and analog front-ends.

Key Specifications

Parameter	Value and Actual Design Meaning
Nominal Zener Voltage (V_Z)	39 V at I_Z = 2 mA - defines primary regulation point in feedback loops
Zener Tolerance	±2% - ensures tight initial voltage accuracy without post-manufacture trimming
Differential Resistance (r_dif)	80 Ω typical - limits output impedance and improves load regulation performance
Temperature Coefficient (S_Z)	−28.7 mV/K at I_Z = 2 mA - enables thermal drift modeling for stability analysis
Total Power Dissipation (P_tot)	500 mW at T_amb = 50 °C - sets maximum continuous power handling in PCB-mounted operation
Reverse Current (I_R)	50 nA max at V_R = 0.7 × V_Znom - ensures low leakage in high-impedance reference nodes
Package	SOD27 (DO-35) - axial-leaded hermetic glass package compatible with through-hole assembly

Pinout & Package

Hermetically sealed axial-leaded SOD27 (DO-35) glass package with cathode indicated by a colored band on one end. No active pin configuration - two-terminal device with anode and cathode leads.

Pin/Terminal	Circuit Role	Design Meaning
Cathode (banded end)	Breakdown terminal	Connected to regulated output node; reverse-biased to maintain fixed voltage drop
Anode (unbanded end)	Reference terminal	Typically grounded or connected to lower potential; completes Zener conduction path

Key Features

Feature	Design Value
±2% Zener voltage tolerance	Enables direct use in precision references without calibration or trimming circuitry
Hermetic SOD27 glass package	Provides long-term reliability and moisture resistance in industrial ambient conditions
500 mW power rating at 50 °C ambient	Supports robust operation in compact PCB layouts without forced cooling
Non-repetitive peak reverse power: 40 W	Allows transient surge suppression capability during short-duration overvoltage events

Applications

Power Supply Feedback Reference

Sensor Biasing Circuit

Use Scenario: Stabilizing output voltage in discrete linear regulators using TL431-like topology with external pass transistor.

IC Role / Device Role / Timing Role: Zener diode provides precise 39 V reference for error amplifier comparison.

Use Value: ±2% tolerance and low r_dif ensure <±1% output regulation accuracy across line/load variations.

Use Scenario: Providing stable excitation voltage to resistive bridge sensors in industrial transmitters.

IC Role / Device Role / Timing Role: Acts as low-drift voltage source for Wheatstone bridge biasing.

Use Value: −28.7 mV/K temperature coefficient allows predictable drift compensation in analog signal conditioning.

Overvoltage Clamp Protection

ADC Reference Buffer

Use Scenario: Limiting input voltage to microcontroller GPIO pins exposed to 48 V field wiring.

IC Role / Device Role / Timing Role: Shunts excess energy above 39 V to ground during ESD or surge events.

Use Value: 40 W non-repetitive peak power rating absorbs 100 μs surges without degradation.

Use Scenario: Generating clean 39 V reference for high-resolution SAR ADC driver stages.

IC Role / Device Role / Timing Role: Supplies low-noise, low-drift reference to op-amp buffer stage.

Use Value: 50 nA max reverse leakage prevents loading of high-impedance reference dividers.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
1N4763A	39 V, ±5% tolerance, 1 Ω higher r_dif, DO-41 package	Higher leakage (100 nA), less suitable for ultra-low-power biasing	Select when cost sensitivity outweighs precision requirements and board space permits larger DO-41 footprint
BZX85C39	39 V, ±5% tolerance, 1.3 W power rating, DO-41 package	Higher P_tot but looser tolerance and no guaranteed r_dif spec	Choose for higher-power clamping where ±5% voltage variation is acceptable

Compared with BZX79-B39,143, the 1N4763A trades tighter thermal stability for lower cost and wider availability, while BZX85C39 sacrifices initial accuracy for greater surge handling - making the BZX79-B39,143 optimal for precision analog references where size, stability, and repeatability are prioritized.

Availability

BZX79-B39,143 is available at Aetrix Electronics and suitable for industrial power supplies, sensor interface modules, and overvoltage protection circuits requiring stable component supply and traceable sourcing.

Supply support for BZX79-B39,143 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, with focus on automotive, industrial, and consumer applications.

The BZX79 series belongs to Nexperia's voltage regulator diode product line, designed specifically for low-power, high-stability voltage reference and clamping in space-constrained through-hole applications.

FAQ

What is the maximum continuous reverse current this diode can handle at 39 V?

The BZX79-B39,143 is not rated for continuous reverse current at full Zener voltage. Its maximum continuous forward current is 250 mA, but in Zener operation, it must be current-limited externally - typically to ≤20 mA for reliable 500 mW power dissipation at 39 V. Exceeding this risks thermal runaway due to its negative temperature coefficient.

Does this diode have a specified Zener impedance curve?

Yes - differential resistance (r_dif) is specified as 80 Ω typical at I_Z = 2 mA, with a maximum of 350 Ω. This value is measured under DC conditions and reflects small-signal AC impedance near the operating point, critical for evaluating regulation stability in feedback networks.

Can BZX79-B39,143 replace BZX79-C39 in existing designs?

No - BZX79-C39 has ±5% tolerance and different test current (I_Ztest = 0.5 mA), resulting in higher r_dif (up to 400 Ω) and looser voltage control. Substituting requires revalidation of regulation accuracy, thermal drift, and loop stability, especially in precision references.

Is the SOD27 package RoHS compliant and lead-free?

Yes - Nexperia confirms the SOD27 package for BZX79-B39,143 meets RoHS Directive 2011/65/EU and is lead-free, with termination finish specified as matte tin (Sn) over nickel (Ni) on copper leads, per manufacturer documentation dated 2022.

BZX79-B39,143 Specifications

Product attributes: Attribute value

Manufacturer:: Nexperia USA Inc.

Series:: -

Package/Case:: DO-204AH, DO-35, Axial

Packaging:: Tape & Box (TB)

Product Status:: Active

Voltage - Zener (Nom) (Vz):: 39 V

Tolerance:: ±2%

Power - Max:: 400 mW

Impedance (Max) (Zzt):: 130 Ohms

Current - Reverse Leakage @ Vr:: 50 nA @ 27.3 V

Voltage - Forward (Vf) (Max) @ If:: 900 mV @ 10 mA

Operating Temperature:: -65°C ~ 200°C

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: ALF2

BZX79-B39,143 FAQ

1.How can I place an order for BZX79-B39,143 through Aetrix?

Please submit a Request for Quotation (RFQ) for BZX79-B39,143 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for BZX79-B39,143 reliable?

The price and inventory of BZX79-B39,143 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX79-B39,143 is usually 5 days.

3.What payment methods are accepted for BZX79-B39,143?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX79-B39,143 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BZX79-B39,143?

BZX79-B39,143 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BZX79-B39,143 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for BZX79-B39,143?

For technical support, including BZX79-B39,143 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX79-B39,143 requirements.

6.How does Aetrix verify that BZX79-B39,143 is sourced from the original manufacturer or authorized distributors?

All BZX79-B39,143 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that BZX79-B39,143 meets industry standards.

7.What is the process for return or replacement of BZX79-B39,143?

All BZX79-B39,143 units undergo pre-shipment inspection (PSI). If there is an issue with BZX79-B39,143, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The BZX79-B39,143 part is unused and in its original packaging.

Return procedure for BZX79-B39,143:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

Tech Hub

2026-09-03 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-01 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…

2026-08-14 Jumper Cables: How to Use, Connect and Choose Them Safely

Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…