Can MOSFET Works on AC ??

[asking]

Hello,

Recently i have seen MOSFET's installed in the circuit on the AC part....so i m confused... because BJT's works on DC only can MOSFET Work on AC ?

Thanks

 

[ArNvC]

Actually, AC can be switched with mosfets in totem-pole config. source to source connected.
This works because fets are actually bi-directional. A positive voltage on the gate (with respect to the source) switches the channel to a low resistance regardless of the direction of current in the channel. So if you choose a fet with a sufficiently low on resistance, the body diode on the reversed fet will not conduct. This can make a very low voltage drop AC switch.

 

[crutschow]

Actually, AC can be switched with mosfets in totem-pole config. source to source connected.
This works because fets are actually bi-directional. A positive voltage on the gate (with respect to the source) switches the channel to a low resistance regardless of the direction of current in the channel. So if you choose a fet with a sufficiently low on resistance, the body diode on the reversed fet will not conduct. This can make a very low voltage drop AC switch.

View attachment 88775

The trick is to keep the gate-source voltage at or above the ON voltage, independent of the AC voltage moving the source voltage over the AC peak to peak value.

 

[goldsmith]

Hello,

Recently i have seen MOSFET's installed in the circuit on the AC part....so i m confused... because BJT's works on DC only can MOSFET Work on AC ?

Thanks

Hi Asking !
Of course they can be easily used in every applications . there is nothing to be surprised about this issue . for more help can you please bring me one of the circuits that you've saw ? then i'll explain it to you .
Best Wishes
Goldsmith