20V MOSFETs for speed 370

[Hell-e-Guy]

I have an e-sky 4 in one that I need to fix. One of the main rotor's speed control MOSFETs burned.
E-Sky use MOSFETs made by Analogic Tech (never heard of the company before) rated at 30V/12A.
I ran out of 30V MOSFETs and I have only 20V/13.5A SO8 MOSFETs.
Can I replace the 30V with 20V FETs?
Will the motor Voltage spikes be a proben for 20V FETs?

[Comatose]

Probably not, unless the board is really poorly designed.

And even so, then you'd just be left with a burned fet, same place you are now, no? I say go for it.

[vintage1]

I agree.

Most boards have a clamp diode to the rails to clamp any spikes that go over rail voltage.

And use the braking FET to clamp reverse spikes.

Biggest problem might be turn on voltage on the gates...if your FETS need more than 5v to turn hard on...you may end up with them getting hot and bothered instead ;)

[z-matrix]

mosfets in half bridge can take huge spikes ;)

[Hell-e-Guy]

Thanks for all the answers !
The FETs that I have now are also logic level with even less gate capacitance than the original.
Comatose, you are right what do I have to loose ???

[z-matrix]

but also check the drivers are not dead, cause, mosfets usually go short to gate - source - drain, thus, gate drivers die too.

[vintage1]

da man speekah da troof, listen to de wise words. :D

[Hell-e-Guy]

Hi,
I replaced the MOSFETs and all is back to normal (for how long ???)
Z-matrix, I checked and the gate was also shorted to ground as you said.
Probably the 100 ohm gate resistor saved the Micro's I/O.

Thanks

[vintage1]

Hi,
I replaced the MOSFETs and all is back to normal (for how long ???)
Z-matrix, I checked and the gate was also shorted to ground as you said.
Probably the 100 ohm gate resistor saved the Micro's I/O.

Thanks

No reason it should not work forever.