Can I use a normal high current diode as a transient voltage suppressor(TVS) ?

Thread Starter

abraar_sameer

Joined May 29, 2017
37
The question is self explanatory. I cannot find a TVS diode with a suitable voltage rating for my application. So, can I use a 'typical' fast diode to clamp high reverse voltages by breaking down? Or will repeated reverse breakdown hurt the diode?
 

Alec_t

Joined Sep 17, 2013
10,907
Reverse voltages are usually clamped (e.g. in logic IC inputs) by a diode passing forward current. Why do you want to rely on a diode's reverse breakdown?
 

Thread Starter

abraar_sameer

Joined May 29, 2017
37
So what is your "application" and what is the source of the voltage you want to clamp?
Sorry for being inactive for a while. My application is to protect the IGBTs in a half bridge inverter for a tesla coil that I'm making from di/dt induced voltage spikes. The switching frequency will be quite high, somewhere around 250 Khz running from rectified 220VAC. I obviously don't need a precision reverse breakdown voltage for that, just somewhere below the 600V collector-emitter voltage rating of the transistor.

By the way, many people get away without a protection diode, even a commercial Tesla coil producer called OneTesla doesn't include it in their boards and instead leave an 'optional' space in the PCB for installing TVS diodes. But, the IGBTs are expensive so I thought I should add a little bit of protection. Here is a schematic from OneTesla:



Those diodes you see attached across the IGBTs are exactly what I'm talking about(at least the purpose).

But I can't find a TVS diode with suitable clamping voltage. Back to my question, can I use a usual diode, probably a fast, high current one ?
 
Last edited:

shortbus

Joined Sep 30, 2009
7,454
I can't find them. I wouldn't have posted this question if I could,
I found them for you. Or you could take the values from the data sheet of that link and look for another brand. Part of doing this electronics hobby is learning to find the parts, or the hunt for the parts.

The only problem is... it will take at least a month to arrive.
So it takes time to get the parts, I can't imagine how the need for a Tesla coil is life threatening.
 
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