Often, the best transient protection is a simple capacitor or ferrite bead designed to slow any change in voltage or current due to an induced transient.

TVS Diode
The Transient Voltage Suppressor diode (also known as a TVS Diode) is a protection diode designed to protect electronic circuits against transients and overvoltage threats such as EFT (electrically fast transients) and ESD (electro-static discharge).

TVS diodes are inherently unidirectional. A bidirectional device can be created by combining two unidirectional diodes, as shown in Figure 5. The electrical characteristics of a common cathode and common anode device are typically equivalent.

Common Types Of Transient Voltage Suppressor

• TVS Diode. A TVS diode shares the same fundamentals of a Zener diode.
• Metal Oxide Varistor. The metal oxide varistor or MOV is an excellent surge suppression device made of ceramic material with zinc oxide grains pressed into it.
• Gas Discharge Tube.
• Polyfuse.

Zener diode
One such common device used for this purpose is known as the transient voltage suppression diode that is simply a Zener diode designed to protect electronics device against overvoltages.

TVS diodes are particularly efficient in countering medium-voltage high-energy pulses that last milliseconds, in comparison to ESD protection devices which address higher voltage pulses of lower energy and shorter duration.

A transient voltage is a temporary unwanted voltage in an electrical circuit that range from a few volts to several thousand volts and last micro seconds up to a few milliseconds. Transient voltages differ from swells by being larger in magnitude and shorter in duration.

The primary way to protect a circuit from overvoltage is to place these TVS devices in parallel with the circuit. There are many types of TVS device that can be used for Transient Voltage Suppression namely Metal Oxide Varistor, TVS Diode, Zener Diode or a Bypass Capacitor.

Types of Transient Voltage Suppressor. There are many types of TVS device that can be used for Transient Voltage Suppression namely Metal Oxide Varistor, TVS Diode, Zener Diode or a Bypass Capacitor. Based on operation, Transient Voltage Suppressors can be divided into two classes, clamping, and crowbar.

Although standard diodes and Zener diodes can both be used for transient protection, they are actually designed for rectification and voltage regulation, and, therefore, are not as reliable or robust as transient voltage suppressor diodes. Transient Voltage Suppressor (TVS) Diode Symbols: Unidirectional (left) and bidirectional (right).

Transient Voltage Suppression (TVS) diodes are useful in protecting electronic circuits from electrostatic discharge (ESD). The TVS diodes used for ESD protection are silicon-avalanche diodes. With a high impedance at the stand-off voltage and low impedance at the breakdown voltage, silicon-avalanche diodes are well suited for ESD protection.