Overheating IRF540 causes gate-drain short?

Thread Starter

AlbertHall

Joined Jun 4, 2014
12,396
I have a circuit using an IRF540 well within its current and voltage ratings.
The MOSFET failed. 54Ω drain-source and 5.1Ω drain-gate.

Would overheating result in a drain-gate short or was there some other problem that caused this?
 

Thread Starter

AlbertHall

Joined Jun 4, 2014
12,396
That's what I was afraid of. I can increase cooling without too much effort but I don't know where any spike could have come from. The circuit is below. I could put a 15V zener directly between the gate and source. Any other suggestions?
 

Thread Starter

AlbertHall

Joined Jun 4, 2014
12,396
Having read the the third link above, I will be adding a capacitor and ferrites at the motor. This is fairly easy to do.
 

Thread Starter

AlbertHall

Joined Jun 4, 2014
12,396
I have added more heatsinking and capacitors (10n & 100n) across the motor and added ferrite rings on the motor wires.
A few, perhaps a dozen, on-off cycles and the MOSFET is short again (all three terminals).:oops:
I am going to use a relay instead. :rolleyes:
 

hrs

Joined Jun 13, 2014
414
Hi Albert,

Just in case you intended to add a diagram in post #5, it's not visible for me. Not that I could help but I thought I'd point that out.
 

Thread Starter

AlbertHall

Joined Jun 4, 2014
12,396
Yes, it seems I did forget to include the diagram but it's too late now. It's been overwritten by the relay version.
 

xainnasir

Joined Nov 8, 2012
15
Hi,

I would recommend you to use IRF540. IRF540 is an NPN MOSFET, which gives excellent results, when it comes to fast switching. :p It works on HEXFET technology and is capable of perforing under critical temperatures. You should have a look at IRF540 Pinout and laso downlaod its Proteus simulation. It will help you in its better understanding.

Thanks.

Moderators note : removed hidden link which is site promotion
 
Last edited by a moderator:

ebp

Joined Feb 8, 2018
2,332
Zombie thread, but ...

The IRF540 is, by modern standards, a very mediocre MOSFET. For reasons I don't understand, possibly that a few million got dumped on the hobby market at low price, it pops up all over the place in the hobby world. If you don't get them at a deep discount there a many much better FETs that cost less.

Note that #11 is yet another occasion of the same person resurrecting a zombie thread in order to promote the webiste at the link.
 

wayneh

Joined Sep 9, 2010
17,498
Note that #11 is yet another occasion of the same person resurrecting a zombie thread in order to promote the webiste at the link.
Did you report that post? I usually do when I see them, even if they are borderline. This one seems blatant.
 

Thread Starter

AlbertHall

Joined Jun 4, 2014
12,396
I don't remember where they came from.
It is switching the spindle (48V 6A) on my CNC so it's only one on/off cycle per tool and the relay seems to be able to cope with that.
 
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