Mosfet gate charge with no voltage across D-S

AI Thread Summary
A MOSFET can still exhibit gate charge even when no voltage is applied across the drain-source (D-S) terminals due to its inherent capacitance. The gate charge is influenced by the gate voltage applied, which can induce a response in the MOSFET's channel, regardless of D-S voltage. This characteristic is important for testing MOSFET driving circuits, as it affects current requirements when the MOSFETs are not connected to a voltage source. Understanding this behavior is crucial for accurately replicating working conditions and diagnosing faults in the circuit. Therefore, even without D-S voltage, gate charge can still be present and impact circuit performance.
Salvador
Messages
505
Reaction score
70
Hi , I would like to find out does a mosfet have any gate charge if there is no voltage applied across D-S or no ?
my intuition tells me that there shouldn't be any gate chrge as there is no voltage on the " second plate" to attract that charge like would be the case in a capacitor, although mosfte being a semiconductor maybe because its current carrying channel is doped with current carriers it responds to gate signal even with no voltage across D-S, ?

I am asking this because I need to test for a fault in my mosfet driving circuit but I need to know whether it has the same current need driving the mosfets without them being attached to voltage or no?otherwise i couldn;t fully replicate working condition and also determine the fault.
 
Physics news on Phys.org
You still have a small capacitance, so applying a gate voltage will lead to a gate charge.
 
Thread 'Motional EMF in Faraday disc, co-rotating magnet axial mean flux'
So here is the motional EMF formula. Now I understand the standard Faraday paradox that an axis symmetric field source (like a speaker motor ring magnet) has a magnetic field that is frame invariant under rotation around axis of symmetry. The field is static whether you rotate the magnet or not. So far so good. What puzzles me is this , there is a term average magnetic flux or "azimuthal mean" , this term describes the average magnetic field through the area swept by the rotating Faraday...
Back
Top