CGD current in Boost SMPS FET...goes through boost inductor?

[treez]

Hello,
When a CCM boost converter switches its FET on, the FET Cgd capacitor has to discharge....can you confirm that the discharge current in the Cgd capacitor must go through the fet.

 

[dimmich]

I believe, Cgd discharge current must pass through the driver circuit, but not through the FET transistor. By the same way as shown in the figure for the displacement current. Because the "gate" end of the capacitor is connected only with the driver circuit and driver circuit in a low output impedance. Through this resistance will discharge the capacitor Cgd. Same Cgs.

The gate of the FET - is isolate electrode, how to can discharge current to go through the insulation? :shock:

 

[treez]

it goes thru the capacitance.
The cgd must discharge thru the fet....the only other routes is thru the inductor or the output diode, and it wont discharge thru those