The 1N4734A 5.6V Zener Diode is a widely used electronic component designed to provide stable voltage regulation, reliable over-voltage protection, and consistent reference performance in a broad range of circuits. This article will discuss the 1N4734A’s specifications, features, pinout, circuit operation, applications, and more.

Catalog

1N4734A Overview

The 1N4734A 5.6V Zener Diode is a silicon Zener diode designed for reliable voltage regulation and reference applications. It maintains a stable 5.6 V output when operated in reverse bias, making it a simple and effective solution for controlling voltage levels in electronic circuits.

The 1N4734A is rated for 1 W power dissipation and comes in a DO-41 axial lead package, which makes it easy to install in through-hole designs. Thanks to its good thermal stability and predictable breakdown behavior, it is suitable for general-purpose power supplies, signal conditioning circuits, and over-voltage protection.

If you are interested in purchasing the 1N4734A 5.6V Zener Diode, feel free to contact us for pricing and availability.

1N4734A CAD Models

1N4734A Pinout Details

Alternatives & Equivalent Model

BZX55C5V6

MMSZ5V6

NTE136A

1N4734A Specifications

1N4734A Features

Silicon planar power Zener diode

The 1N4734A is manufactured using silicon planar technology, which improves junction stability and long-term reliability. This construction helps the diode maintain consistent electrical characteristics under continuous operation and varying electrical stress.

Designed for voltage stabilization and clipping circuits

This Zener diode is well suited for stabilizing voltage levels and limiting signal peaks in electronic circuits. By maintaining a steady Zener voltage, it helps protect sensitive components from voltage fluctuations and transient spikes.

High power dissipation capability

With a power rating of up to 1.3 W, the 1N4734A can safely handle higher energy levels compared to low-power Zener diodes. This makes it suitable for power supplies and regulator circuits where heat dissipation is a concern.

Standard Zener voltage tolerance of ±5 %

The diode offers a controlled Zener voltage with a ±5 % tolerance, allowing predictable circuit performance. This balance between accuracy and cost makes it practical for general-purpose regulation designs.

Low dynamic (Zener) impedance

A low Zener impedance improves voltage regulation by minimizing voltage variation as current changes. This characteristic helps deliver a more stable output voltage in real operating conditions.

Wide operating temperature range

The 1N4734A operates reliably across a broad temperature range, supporting performance in both industrial and automotive environments. This allows use in systems exposed to heat, cold, or changing thermal conditions.

AEC-Q101 qualified for automotive applications

Qualification under AEC-Q101 indicates the diode meets strict automotive reliability and stress-testing standards. This makes it suitable for use in vehicle electronics where durability and consistency are required.

Axial-lead DO-41 package

The standard DO-41 axial package allows easy through-hole mounting and strong mechanical support. This package is widely supported in PCB designs and simplifies manual or automated assembly.

Good surge and transient handling capability

The device can tolerate short-duration voltage surges, helping protect circuits from unexpected electrical disturbances. This feature enhances overall system robustness and longevity.

1N4734A Working in Circuit

1N4734A as Voltage Sense and Transistor Control (Solar Panel LM317 Circuit)

In the first diagram, the 1N4734A Zener diode is used as a voltage reference and control element for the LM317 regulator and BC547 transistor. The solar panel supplies power through a Schottky diode to the LM317, which regulates the output voltage. When the output voltage rises and reaches the Zener breakdown level of the 1N4734A, the Zener begins to conduct. This conduction provides base drive to the BC547 transistor through the resistor network. As the transistor turns on, it pulls current from the LM317 adjustment pin, effectively reducing the regulator’s output voltage. In this way, the 1N4734A senses over-voltage conditions and, with the help of the transistor, actively limits the output to protect the USB load from excessive voltage.

1N4734A as a Signal Clamp in a Diode–Zener Limiter Circuit

In the second diagram, the 1N4734A operates as a voltage clamping device for an AC input signal. The input sine wave is coupled through a capacitor, allowing only the AC component to reach the output node. When the signal voltage remains below the Zener voltage, the 1N4734A stays off and the output follows the input waveform. Once the signal exceeds the Zener breakdown level, the 1N4734A conducts and clamps the voltage to a fixed level relative to ground. The series diode ensures correct current direction and protects the Zener during opposite polarity swings. This arrangement prevents the output from exceeding a safe voltage, making it suitable for protecting transistor inputs or sensitive signal-processing stages.

1N4734A as Over-Voltage Protection in a Transistor Power Supply Circuit

In the third diagram, the 1N4734A is used to protect a transistor-based power supply feeding a linear regulator and microcontroller. The transistor and transformer stage generate a DC voltage that is filtered by a capacitor before entering the regulator. Under normal conditions, the Zener diode remains inactive. If the supply voltage rises above the Zener voltage due to load changes or switching behavior, the 1N4734A conducts and clamps the voltage to a safe level. This prevents excessive voltage from reaching the regulator input and downstream electronics. By limiting voltage spikes, the Zener diode reduces stress on the transistor, improves supply stability, and enhances overall circuit reliability.

1N4734A Applications

• Voltage regulation in low-power DC power supplies

• Output voltage limiting for linear regulators such as LM317

• Over-voltage protection for microcontrollers and logic circuits

• Signal clipping and waveform limiting in analog circuits

• Voltage reference source in transistor biasing networks

• Input protection for ADC and sensor interfaces

• Solar charger output voltage control circuits

• Battery-powered device voltage stabilization

• Transient voltage suppression in low-energy circuits

• Protection of communication and control signal lines

• Level shifting and voltage threshold detection circuits

1N4734A Safely Operation

Operate the 1N4734A within its rated Zener voltage and power dissipation limits to avoid overheating and long-term damage. Ensure adequate series resistance to limit Zener current during breakdown operation. Maintain proper heat dissipation, especially in continuous regulation circuits. Avoid reverse or forward current beyond specified limits, and keep operation within the recommended temperature range. Proper PCB spacing and correct polarity connection help ensure stable and reliable performance.