How to Choose the Right TVS Diode for Transient Protection

In the modern context of an electronic environment, TVS diodes are indispensable to safeguarding essential electronic subassemblies from variations in voltage. These diodes are intended to behave effectively to the sudden and unpredicted voltage fluctuations in the circuit, it gives adequate protection against the high dangerous voltages that result from sources such as lightening, ESD and others.

Selecting the right TVS diode for your application is very important for offering good protection and longevity of the devices. Understanding of the workings of a TVS diode, it’s applications and how to determine the right type to use in protection against transients can be better explained using this blog.

 How TVS Diodes Work

TVS diodes are semiconductor devices that are used exclusively to shield electronic circuits against transient voltages. During an input voltage surge, the television surge protection diode becomes very conductive and provides a controlled low value, which limits the applied voltage and effectively redirects high energy to the ground. However, when the event is transient, the TVS diode switch to a non-conductive state thus enabling normal operation to take place.

TVS diodes are remarkable at providing fast responses dependent on voltage fluctuation and most TVS diodes have response times of below nanoseconds and they protect high-speed data lines as well as other sensitive electronics. These are available in the forms of unidirectional and bidirectional to meet various circuit necessities.

 Applications of TVS Diodes

TVS diodes are employed in voltage applications, to or across several industries and forms of technology where transient voltage management is significant. Some common applications include:

1. Automotive Electronics: Shielding from voltage transients resulting from load dump, ESD and other transient phenomena on electronic control units (ECUs), Sensors, and infotainment systems.

2. Telecommunications: Protection of Modem / routers / base station etc. That are affected by lightening surge and ESD.

3. Consumer Electronics: Shielding gadgets such as Smartphone’s, tablets, laptops, and other electrical devices against ESD, other types of TVS.

4. Industrial Equipment: Protection of industrial control systems, automation devices, and power supplies from the impact of transients.

5. Medical Devices: The shielding of critical medical devices from ESD and transient voltage to prevent harm to the patient and failure of the equipment.

 How to Choose the Right TVS Diode for Transient Protection

To decide on which TVS diode will be most suitable for the specific protection needs of the application we need to consider the following parameters. Here are the essential parameters to evaluate:

 1. Working Voltage

The working voltage, also known as the reverse standoff voltage is the maximum operational voltage the TVS diode can tolerate without conducting. When selecting the TVS diode it would be most appropriate the select one whose voltage rating is slightly higher than the normal voltage in the circuit.

 2. Breakdown Voltage

Breakdown voltage, this is the voltage at which the TVS diode starts to conduct as well as limit the amount of voltage. Usually, one should choose the breakdown voltage of the TVS diode which is enough to protect the circuit from higher voltage but did not affect the normal working of circuit.

 3. Clamping Voltage

Clamping voltage refers to the maximum voltage which the TVS diode will let through across its terminals during a transient event. In order to provide optimum protection, it is mandatory to select a TVS diode with clamping voltage lower as compared to the maximum voltage rating of the components to be shielded.

 4. Peak Pulse Current

The pulse current at the maximum is the limiting current level that the TVS diode can accommodate during a transient event. It is recommended to choose a TVS diode with a higher rating than anticipated spike current through the transients in your application.

5. Power Dissipation

The power dissipation rating specifies the maximum power that the TVS diode can at any given period of time transfer in case of a transient event. Some applications demand high energy transients and thus require higher power dissipation ratings of the device.

 6. Response Time

TVS diodes have to reflect to transient events adequately in order to protect the equipment. It is therefore important to choose a TVS diode with a high response time for radar systems and other high speed data lines.

 7. Packaging and Mounting

Look at the packing and mounting constraints of the system in the chosen application. TVS diodes come in several package forms for mounting although the most common forms include SMT and TH. It is recommended to select a package that will be suitable for your design and manufacturing activities.

 8. Unidirectional vs. Bidirectional

Decide whether you need a one-way or an alternative TVS diode on your application. Unidirectional TVS diodes are normally applied in DC systems, bidirectional TVS diodes on the other hand are well-suited for AC systems and bidirectional signal conducts.

 Conclusion

Safe your devices and their service life by selecting suitable TVS diode for your project. Visit, Millennium Semiconductors website for more information on our TVS diode products and how we can help you to find the right part for your transient protection application. Currently at Millennium Semiconductors work with many top suppliers that include Littelfuse, Vittorsemi, JJM, Taiwan Semiconductor, YJ, ROHM, Panjit, and Semtech for our lineup of high quality TVS diodes for consumer electronics, telecommunications, automotive or industrial, our staff is ready to provide with the most suitable TVS diode solution.