What Are Zener Diodes and Their Operation?

In the realm of electronics, a diode is simply a two-terminal component capable of conducting current in a single direction. The single conducting path is made possible through a low resistance being present in one direction while having high resistance in the other, and this capability allows diodes to be used as rectifiers, voltage regulators, switches, signal mixers, oscillators, and more. Depending on one’s needs, there are a number of diode types that are commonly available, each featuring distinct properties that allow them to benefit certain applications. One of these distinct diode types is the Zener diode, that of which we will briefly discuss in this piece.

While a stark majority of diodes follow the standard process of only permitting current to flow in a single direction, Zener diodes are specialized as they can actually permit backward flow when a specific voltage value known as Zener voltage is reached. When a typical solid-state diode faces current values that surpass reverse breakdown voltage levels, it will often result in an avalanche breakdown which can cause damage from overheating. To prevent such an occurrence, diodes in these environments are designed with a Zener voltage value that ensures a controlled breakdown occurs instead of damage. For example, if a diode exhibits a Zener breakdown voltage of 3.2 V, it will have a voltage drop that is close to 3.2 V across a high range of reverse current values. As a result of this functionality, Zener diode components are regularly used for overvoltage protection and voltage stabilization for low-current applications, as well as for machinery that requires the production of a reference voltage.

Different Zener diodes may vary in their Zener voltage and operations baked on the doping of their p-n junction. In order for electrons to effectively tunnel between the p-type material’s valence band and the n-type material’s conduction band, the depletion region of the diode will be kept very thin, even for very low reverse bias voltages. To best manage the breakdown voltage, the doping process is controlled with tolerances of 5%, 10%, and more. For most Zener diodes, breakdown voltage values will sit between 1.2 V and 200 V on average.

As discussed before, Zener diodes can perform a number of useful roles based on their construction and capabilities, and we will discuss a few examples. For small circuity, Zener diodes regularly act as voltage reference or shunt regulators for voltage regulation. When a Zener diode is implemented with parallel connection to a variable voltage source, it will conduct voltage in the reverse direction when the breakdown value is surpassed. From there, the diode will maintain the value through its low impedance. Another example of use is when two diodes are placed in series while facing each other, allowing each to clip a half of an input signal to act as waveform clippers. While this can be used to reshape a signal, it can also deter voltage spikes. Alongside such examples, Zener diodes find many other uses that increase their importance.

Like all electronic components, Zener diodes may eventually break down and fail, necessitating their regular inspection and maintenance. If you have an application or system that has aging or defective Zener diodes, it may be time to begin sourcing replacement parts. Luckily for you, Fulfillment 3sixty is the perfect distribution platform with countless new, used, obsolete, and hard-to-find electronic components readily available for purchase at any time.

Fulfillment 3Sixty is a premier purchasing platform belonging to the ASAP Semiconductor family of websites, and we operate with AS9120B, ISO 9001:2015, and FAA AC 00-56B accreditation as a result of our steadfast dedication to quality control and regulation compliance. If you happen to be facing a time constraint and require parts fast, rest easy as we offer expedited shipping speeds that are made possible through our expansive supply chain network stretching across the United States, Canada, and the United Kingdom. To begin the purchasing process, first start with a quote for your comparisons which you can receive through the submission of an online RFQ form. Once we receive your request, a team member will rapidly formulate a customized solution and present it to you within 15 minutes. See why customers continuously rely on us for all their operational needs when you begin sourcing Zener diodes and other electronics from our platform.


October 21, 2020

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