I'm seeking recommendations for an inexpensive capacitor that will handle fairly-large pulse currents. Maximum voltage is 15 Vdc applied to the capacitor and I'd like to see current pulses in the 100A range if possible.
I will increase the supply voltage if necessary.
Expected pulse width is determined by the total circuit resistance and is expected to be less than 20us. Repetition rate is about 500 Hz.
My current setup is using a IRF540 MOSFET (RDSon 44 milliOhms max) and a 2u2 250V MKT film capacitor from Epcos (TDK) discharging into a total resistance of less than 0.2 Ohms. Gate drive is about 12V with rise time better than 100ns and fall time better than 200ns.
This current setup is giving me a peak current somewhat more than 20 A and the film capacitor is running slightly above ambient temperature.
I can go to a much better MOSFET but I think that my main limiting factor is the capacitor.
My gut tells me that a ceramic capacitor is going to give me better results than the film capacitor. Question is: Which ceramic capacitor?
Or is there a better capacitor choice that I should be exploring?