Relationship between MOSFET and Magnetic field.

magnetic fields affect all types of circuits (electrical), independent from the nature of the component!

but there are circuits were it is more "visible" the interference, this is , more sensitive.

other factors; temperature, voltage in the gate , etc...

I suppose it's theoretically possible to affect the operation of a MOSFET circuit with a strong magnetic field, but it would have to be a changing magnetic field to induce currents.

Other factors may be switching speed, which can cause failure at high switching speeds.

Too little time and too much to tell about the subject. More later?

You don't say specifically what's happening, other than hinting that something may be affecting the characteristics of a MOSFET.

You also mention "MOSFET circuit." What kind of circuit? What's the MOSFET doing?

What specific characteristic changed?

When I mentioned switching speed above, there are a couple of things which happen to MOSFET's, expecially in older devices, and those are slow reverse recovery time of the internal reverse diode (not necessarily present in all MOSFET's), which makes the MOSFET to appear to not turn OFF as fast as it is should based on values in data sheet. And there's a phenomena called "punch-through" (of the oxide layer) due to inductive voltage spikes when shutting OFF. Punch-through may not destroy the device immediately, but it will certainly have an effect on the characteristics, and it will eventually destroy the device if it is continuously subjected to voltage spikes.

I looked up "Failure modes of MOSFET's" and got a few hits on Ask.com.

well, you are all allright, but the question is a bit general, so I´ve given a general answer.

magnetic interference is always unwellcome in circuits and that´s the idea that I was trying to explain.

or not?

In practice probably no.

But doubtless a strong enough magnetic field will effect just about anything (it makes my tail fluff out!)

ofcause it is, especially mosfet is a high resistance device, its very sensitive to those field change.

but most conditin is the field is change frequently.

use shield wire or good grounding to avoid it as possible as you can.

if you have a gate current and you add a magnetic field you might get some hall type effect since they are high impedance devices. an experiment will tell you if the effect if trivial or not.

http://www.google.ca/search?hl=en&sa=X&oi=spell&resnum=1&ct=result&cd=1&q=FET+%2B%22magnetic+field%22&spell=1

lots of hits

Its useful, I hvnt ever pay attation to this application.

thanks for yor web list.

I think it's going to take one heck of a large magnetic field to generate a current in a MOSFET because there isn't any analog of a coil device in the silicon. If you had an inductor in the circuit close to the MOSFET without protection diodes that could be a problem. But overall I don't think there's going to be an effect unless you are at an extreme level of magnetic flux density.

You won't get a Hall effect in a MOSFET because there is no coil or ferrous material.

you do have a flat conductor in the two gate FET and a mag field you will get charge deflection.

Well, I learned something . . .

See Two Drain MOSFET or MAGFET

in one site, one guy ask can he control jfet by magnetic field?

I think he can implement it by using GMR method.

despite it add cost.

Also need to be note flyback voltage, which occurs during turn-off inductive load. In this case MOSFET are in avalanche state because of drain-source voltage exceeded breakdown voltage. There is no connection with magnetic field, just with energy stored in coil.

Magnetic field is too weak at room temperature to affect conventional devices.