I am operating some mosfets in the 50-500khz range, and wish to improve performance, reduce losses and very important reduce emi. I am using a resistor on the gate on the drive with a 12v zener and 10k resistor to ground/0v to try and adsorb transient voltages at the gate.
My question is, if i wish to permit 50-500khz operation / switching, but reduce emi and parasitic oscillations from the device, while maintaining fast switching, would i benefit from ferrites and would you be able to suggest some suitable options/ where to place (is it between gate drive resistor and gate?)
I Occasionally detect parasitic of multiple mhz that i wish to suppress.posting an exact schematic is not possible at this time but looking for advice anyway.
Thanks in advance
Edit: I'm really sorry for not posting a schematic when asking the question originally, main reason is that i don't have permission for what im working on at the moment but i work with a number of switching circuits in the khz region and was postulating about how one might stop ringing at the gate, while not slowing switching, after choosing fast components and suitable gate drive etc. The question was general in that i understand a resistor on the gate of a mosfet can help provide some level of dampening, and routinely use them, but wished to know if a ferrite placed in the gate drive would be a good or bad idea in general to clean operation up more.
However to try and present something of a similar situation ive had a go this morning and dusted off an old mazilli zvs fly back driver from my tesla coil as i can switch it through a suitably sized inductor to achieve the same frequencies my circuit switches at and although the parasitics are slightly higher in frequency and amplitude in my test, they seem to occur in a similar fashion in that circuit too. I am scoping the gate and the source seperately and can see them occuring on switching. Although its a different circuit, my question, badly worded, was general as to whether a ferrite, placed on / inline to the gate of the fet would reduce ringing and emi? As a practical curiosity where i don't actually have any suitably sized ferrites in my parts boxes to test practically at the current point in time.
Link to a mazilli zvs (different situation but similar and somewhat exaggerated problem):