Transient Voltage Suppressor Diode Working

[SACHIN C]

GUMY,
So P6KE13A should be used?
Observing datasheet don't think so?



Thanks & waiting for support to enhance the knowledge,:thinker:

 

[FvM]

I fear, the question misses basic specifications. What's the regular gate-source voltage in the application (e.g. driver supply voltage), what's the expected surge current driving the suppressor diode?

I agree, that a 18 V TVS diode won't protect against exceeding Vgs,max of e.g. 20 V for standard MOSFETs.

 

[SACHIN C]

FvM,
The expected surge current through Gate path will be around 1.5A & Vgs = 18V nominal.Driver Supply Voltage is also 18V.MOSFET can work upto 24V maximum.

Thanks & waiting for support to enhance the knowledge,:thinker:

 

[FvM]

Sounds like you have exotic devices, e.g. SiC MOSFET?

 

[SACHIN C]

FvM,
Yes the device is SiC.
But,what is selection criteria for TVS Diode?
Can we connect TVS diode across Drain to Source?


Thanks & waiting for support to enhance the knowledge,:thinker:

 

[FvM]

Can we connect TVS diode across Drain to Source?

Literally, this depends on your solder skills.
I guess you are asking if it serves a purpose respectively involves disadvantages.

The answer depends on the nature and level of expected overvoltage events. Firstly I would ask if the transistor's avalanche capability can't keep up with possible voltage spikes. Regarding disadvantages, TVS diodes have slow recovery and considerable capacitance. In so far you should check for increased switching losses. Similarly it's questionable if you should connect regular 600W (or even larger) TVS diodes parallel to the gate source terminals of a fast switcher. It's probably O.K. for slow high power IGBTs. For MOSFETs, I would rather use small high speed limiter diodes. The problem of finding a suitable voltage threshold is unfortunately the same.

 

[SACHIN C]

FvM,
So in place of TVS Diode at Gate to Source we can use high speed Diode in reverse condition?
The Surge wattage,Reverse time,Voltage rating parameter of Diode will play big role in selection of fast acting diode?

Thanks & waiting for support to enhance the knowledge,:thinker: