Nexperia USA Inc. BZX79-C27,133

Overview

BZX79-C27,133 from Nexperia is a ±5% tolerance Zener voltage regulator diode with nominal breakdown voltage of 27 V at 2 mA test current, 65 Ω typical differential resistance, and 18.0 mV/K temperature coefficient. It operates in low-power stabilization circuits requiring stable reference voltages up to 27 V, such as power supply feedback networks and analog sensor biasing.

For engineers reviewing the BZX79-C27,133 datasheet, BZX79-C27,133 pinout, BZX79-C27,133 application, or BZX79-C27,133 equivalent, key selection criteria include Zener voltage tolerance (±5%), thermal resistance (380 K/W), non-repetitive peak reverse power (40 W), and DO-35 package compatibility with through-hole PCB assembly.

Technical Context

This Zener diode functions as a two-terminal voltage reference device operating in reverse-biased breakdown mode. Its electrical behavior is defined by a specified Zener voltage (27 V) at 2 mA test current, with differential resistance of 65 Ω (typ.) and temperature coefficient of +18.0 mV/K - indicating positive drift with rising junction temperature.

The device uses a hermetically sealed glass SOD27 (DO-35) package with axial leads and cathode band marking. Thermal performance is characterized by R_{th j-a} = 380 K/W under standard mounting conditions (unmetallized PCB, 8 mm lead length), limiting continuous power dissipation to 400 mW at 50 °C ambient.

Key Specifications

Pinout & Package

Hermetically sealed glass SOD27 (DO-35) package with axial leads; cathode identified by a dark band on the glass body. Lead pitch is not standardized but conforms to JEDEC DO-35 mechanical dimensions (L min. = 25.4 mm, D max. = 1.85 mm, b max. = 0.56 mm).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4748A and BZX55C27, BZX79-C27,133 offers optimized thermal resistance (380 K/W) for compact layouts and tighter manufacturing consistency within the Nexperia BZX79 series, making it preferred for space-constrained industrial control modules.

Availability

BZX79-C27,133 is available at Aetrix Electronics and suitable for power supply feedback, sensor bias reference, overvoltage clamp, and microcontroller reset circuits requiring stable component supply and long-term parametric consistency.

Supply support for BZX79-C27,133 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 semiconductors, formed in 2017 from the former NXP Standard Products division, with focus on automotive, industrial, and computing applications.

The BZX79 series belongs to Nexperia's voltage regulator diode product line, designed specifically for low-power, cost-sensitive voltage reference and stabilization tasks in consumer and industrial electronics.

FAQ

What is the maximum continuous reverse current this diode can handle at 27 V?

The BZX79-C27,133 does not specify a maximum continuous reverse current independent of power dissipation. At 27 V, its absolute maximum continuous power is 500 mW at 50 °C ambient, implying a theoretical max reverse current of ~18.5 mA (500 mW ÷ 27 V). However, practical operation must stay within the 2 mA test current region to maintain specified Zener voltage and differential resistance.

Can this Zener diode be used in surface-mount designs?

No - the BZX79-C27,133 uses a through-hole SOD27 (DO-35) glass package with axial leads and is not compatible with SMT reflow processes. For surface-mount equivalents, consider Nexperia's MMBZ52xx series or PZMxx series Zeners in SOT-23 or SOD-123 packages.

How does the +18.0 mV/K temperature coefficient affect circuit accuracy?

A +18.0 mV/K coefficient means the Zener voltage increases by approximately 18 mV per Kelvin rise in junction temperature. Over a 100 °C range (−40 °C to +60 °C), this causes ~1.8 V shift - critical in precision references. Compensation techniques (e.g., complementary tempco components) are needed for sub-1% accuracy across wide temperature ranges.

Is the cathode marked on the physical device?

Yes - the cathode is clearly marked by a dark band on the glass body of the SOD27 (DO-35) package. This band aligns with the cathode terminal in the schematic symbol and must be oriented toward the higher-potential node in Zener operation.