I am working on a powerboard that may need to switch up to 2kA and while working on some simulations the question occurred to me. How much current can flow in/out of a ceramic smd capacitor when constrained to a very small time frame? For example; the capacitor is 10uF and 100V and the pulse is 0.1-1us, which equates to a frequency of 1-10MHz, and in the datasheet for the capacitor this gives an ESR and characteristic impedance of about 0.01 Ohms. Staying within the 100V rating, this gives a peak current of up to 10kA. Will capacitors actually allow current at that level, even for such a short duration, or is there some other factor that comes into play?
Assume 10nH total inductance. Given V = L * dI/dT, or conversely, I = 1/L * integral (V * dT),
the peak I = 1/10nH * integral (100V * 100nS) = 10^+8 * 100 * 1e-7 = 1,000 amps.
If your total inductance (caps plus solder pads plus GND inductance of vias + vias to a shared high current bus) is 100nH, the peak current is only 100 amps.