Nexperia USA Inc. BZX79-C36,133

Overview

BZX79-C36,133 from Nexperia is a ±5% tolerance Zener voltage regulator diode in a hermetically sealed SOD27 (DO-35) glass package, rated for 36 V nominal working voltage at 2 mA test current, 500 mW total power dissipation at 50 °C ambient, and 45 nA reverse current at 25.2 V (0.7 × V_Znom). It serves as a low-power voltage reference in analog signal conditioning and power rail stabilization circuits.

For engineers reviewing the BZX79-C36,133 datasheet, BZX79-C36,133 pinout, BZX79-C36,133 application, or BZX79-C36,133 equivalent, this part is selected for precision low-current biasing, fixed-voltage clamping in sensor interfaces, and overvoltage protection in battery-powered instrumentation where ±5% tolerance and 80 Ω differential resistance at 2 mA are design-critical parameters.

Technical Context

This Zener diode operates in reverse breakdown mode with a specified 35.3–36.7 V working voltage range at I_Ztest = 2 mA. Its temperature coefficient is +26.0 to +37.4 mV/K, indicating positive drift with junction temperature - critical for thermal stability analysis in unregulated supplies.

The device exhibits 80 Ω typical differential resistance at 2 mA, enabling predictable dynamic impedance behavior under small-signal AC perturbations. Its 45 pF capacitance at 0 V reverse bias and 1 MHz makes it suitable for DC/low-frequency regulation but not RF bypass applications.

Key Specifications

Pinout & Package

Hermetically sealed axial-leaded SOD27 (DO-35) glass package with cathode indicated by a band. Leads are tinned copper-clad steel; body diameter 1.85 mm, length 4.25 mm, lead spacing 25.4 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4738A, BZX79-C36,133 offers smaller SOD27 footprint and lower leakage but less surge robustness; compared with BZX79-B36,113, it trades ±2% accuracy for lower unit cost while retaining identical thermal and dynamic characteristics.

Availability

BZX79-C36,133 is available at Aetrix Electronics and suitable for industrial sensor conditioning, portable instrumentation power clamping, and automotive cabin control panel designs requiring stable component supply with consistent parametric performance across production lots.

Supply support for BZX79-C36,133 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 designed specifically for low-power voltage regulation and reference applications in cost-sensitive, high-reliability embedded systems.

FAQ

What is the maximum continuous reverse current this diode can handle at 36 V?

The BZX79-C36,133 is not rated for continuous reverse current at its nominal Zener voltage. Its specified continuous forward current is 250 mA, but in reverse breakdown, power dissipation must stay within 500 mW at 50 °C ambient. At 36 V, that limits continuous Zener current to approximately 13.9 mA - exceeding this risks thermal runaway and permanent damage.

Can this diode replace a BZX79-B36 in an existing design?

Yes, electrically - both share identical V_Z range (35.3–36.7 V), package (SOD27), and thermal specs. However, the ±5% tolerance of the C-series introduces up to ±1.8 V variation versus ±0.7 V for the B-series. If system accuracy depends on tight voltage matching, revalidation of bias points and regulation margins is required before substitution.

How does the +26 to +37.4 mV/K temperature coefficient affect circuit performance?

This positive temperature coefficient causes the Zener voltage to increase ~0.1% per °C rise in junction temperature. In a 50 °C ambient-to-junction rise, V_Z shifts +1.5 to +2.2 V - significant in precision references. Designers mitigate this via thermal isolation, low-power operation, or pairing with negative-TC components like forward-biased diodes in compensated references.

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

Yes - the SOD27 (DO-35) package has standardized axial leads with 25.4 mm pitch and tinned finishes, fully compatible with wave soldering and selective soldering equipment. Lead diameter (0.56 mm max) and body dimensions meet IPC-7351 Class L requirements for manual and automated insertion, provided board hole size and pad layout follow Nexperia's recommended land pattern.