Nexperia USA Inc. BZX79-C39,113

Overview

BZX79-C39,113 from Nexperia is a ±5% tolerance Zener voltage regulator diode in a hermetically sealed SOD27 (DO-35) glass package, rated for 39 V nominal Zener voltage at 2 mA test current, 500 mW total power dissipation at 50 °C ambient, and 40 Ω typical differential resistance. It serves as a low-power voltage reference in analog front-ends, power supply feedback networks, and overvoltage protection circuits.

For engineers reviewing the BZX79-C39,113 datasheet, BZX79-C39,113 pinout, BZX79-C39,113 application, or BZX79-C39,113 equivalent, this page delivers verified electrical parameters, thermal behavior, junction-to-ambient thermal resistance (380 K/W), cathode-marked axial lead configuration, and direct alternatives with documented voltage tolerance and dynamic impedance differences.

Technical Context

This device operates in reverse breakdown mode to maintain stable DC voltage under varying load or input conditions. Its Zener voltage is specified at I_Ztest = 2 mA, with temperature coefficient of +28.7 mV/K (typical) and capacitance of 45 pF at 1 MHz and 0 V reverse bias - critical for noise-sensitive reference designs.

The diode exhibits non-repetitive peak reverse power dissipation up to 40 W for 100 μs pulses, enabling transient suppression in low-energy surge scenarios. Thermal resistance from junction to ambient is 380 K/W (lead length ≤8 mm, no PCB metallization pad), defining safe continuous power derating above 50 °C ambient.

Key Specifications

Pinout & Package

SOD27 (DO-35) is a 2-terminal axial-leaded glass package with cathode identified by a colored band. No PCB pad metallization assumed; leads ≤8 mm long. Device is not polarized for forward conduction in normal operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX79-C39,113, the 1N4739A offers double the power rating in a larger package, while BZX85C39 provides 1.8× higher surge current and 2.6× higher continuous power - both trade compact SOD27 size for enhanced ruggedness and thermal performance.

Availability

BZX79-C39,113 is available at Aetrix Electronics and suitable for industrial power supplies, sensor signal conditioning, overvoltage clamp circuits, and embedded reference designs requiring stable component supply with full traceability and lifecycle management.

Supply support for BZX79-C39,113 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.

The BZX79 series belongs to Nexperia's Zener diode product line, engineered for cost-effective, stable voltage regulation in space-constrained, low-power applications where hermetic sealing and E24-standardized voltages are essential.

FAQ

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

The BZX79-C39,113 does not specify a maximum continuous reverse current independent of power dissipation. At 39 V, its absolute maximum continuous reverse current is limited by P_tot = 500 mW, yielding I_Z ≤ 12.8 mA at 39 V - assuming full voltage drop across the diode and T_amb ≤ 50 °C. Derating applies above that temperature.

Is the cathode marked on the BZX79-C39,113 package?

Yes - the cathode is indicated by a distinct color band (typically black or dark stripe) on the glass body of the SOD27 (DO-35) package. This marking aligns with JEDEC DO-35 standards and is visible before and after PCB mounting.

Can this Zener diode be used in AC signal clipping applications?

Yes - its symmetric forward voltage (~0.9 V at 10 mA) and controlled reverse breakdown make it suitable for bidirectional clipping at ±39 V/±0.9 V. However, its 45 pF capacitance may attenuate signals above ~10 MHz, and thermal limits restrict duty cycle in repetitive pulse applications.

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

With a typical temperature coefficient of +28.7 mV/K, V_Z increases by ~4.7 V across a 165 K span. For a 39 V nominal rating, this yields ~12% drift - making it unsuitable for wide-temperature precision references but acceptable for coarse stabilization where drift is compensated elsewhere in the system.