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What is the difference bweteen TVS diode and ESD. Though both of the functions are the same, which do we need to choose for what application?

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    \$\begingroup\$ A TVS is a type of diode that can be used to suppress ESD. An ESD diode describes what a diode is being used for and isn't a specific construction of diode. Similar to how a poodle is a breed of dog that can be used for hunting, whereas a hunting dog more how a dog is used than a breed of dog. A poodle is always a poodle, even if it isn't trained for hunting. Only if it (or any dog of another breed) is trained for hunting is it a hunting dog. \$\endgroup\$
    – DKNguyen
    Aug 6, 2021 at 5:04

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A TVS diode is typically capable of much higher power than ESD diodes.

TVS - "Transient Voltage Suppression" can, if rated accordingly, be capable of suppressing surge pulses - these are pulses that have several hundred volts (and a generator capable of sourcing several hundred of amperes) for a few microseconds. A few microseconds might not sound like much, but if you apply these pulse to a normal component it will literally explode. As a result many TVS components are quite large.

ESD diodes - "ElectroStatic discharge" are designed to protect against ESD. These pulses can have even higher voltage than a surge pulse, but they are below 1 nanosecond. Similar to surge these short pulses can destroy a normal component but the damage will be invisible and often latent. Still, there are several order of magnitude in difference between a surge and a ESD pulse, so many ESD diodes are tiny, but the internal bonding, junctions, etc, are larger than normal components.

So a TVS can be used for ESD protection, but many diodes with ESD protection will explode if you try to use them as a TVS component.

All of these components have detailed datasheets listing the ratings, so those must be read and the component must be used correctly.

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    \$\begingroup\$ Also: they are really specialized kind of avalanche diodes, sold as 'zener' for the higher voltages. Handle then in calculation as zeners. They are simply optimized for speed and dissipation \$\endgroup\$ Aug 6, 2021 at 7:27
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    \$\begingroup\$ The TVS diodes I have looked at were rated according to working voltage and also clamping voltage upon application of a specific test waveform (current waveform). So the idea is that the transient energy will be dissipated in the diode when it conducts and clamps the voltage to a level that is survivable for the protected device or equipment. \$\endgroup\$
    – user57037
    Aug 6, 2021 at 8:03
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I have found that the terms TVS and Zener diodes are used many times to mean the same as far as ESD application is concerned.

As someone has said, my understanding is that a TVS is a kind of Zener that is used for EMC protection.

The parameters to watch are diode cap (lower the better), peak power, continuous operational withstand and min & max breakdown voltages and the clamping voltage.

Usually a diode (Zener or TVS) would have a bigger package and be more expensive as the peak power rating goes up.

One must ensure that the energy withstand of the diode is above the energy supplied by the EMC surge (ESD or surge waveforms). One can use LTSpice to simulate the ESD, surge, etc. to calculate various parameters and ensure the diode used is suitable.

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    – Community Bot
    Jul 11, 2022 at 4:43

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