Standard disclaimer: I'm not an EE, just a hobbyist. I could be missing some fundamental concept here.
Though not limited to regulators this is how this question started for me. When looking at linear regulator datasheets you always see something like this (values and regulator model are just for show):
I get the point of the capacitors is to bypass: filter high frequency noise and provide fast response to spikes (with larger caps). I will restrict the thread to the first question I have.
Regarding CIN, it's supposed to shunt high frequency noise. I know it works but I don't understand how this setup actually doesn't cause issues. If
Zcin = 1/(2*pi*f*Cin) and
f = 10khz and
Cin = 220uF then
Zcin = 0.07 ohms (ignoring ESR). I'm not sure if there's an integration trick to calculate the noise current but simplistically I'm thinking if the amplitude of the noise is 100mv then
I = 1.38A. That's a ton to draw, no?
I must be thinking about this wrong because I've also tried another experiment. I connected a signal generator with a sine wave with an amplitude of 0.1V on top of a DC 1V offset to the power rails of a breadboard. I placed a 47uF cap on the rails as well and the scope showed an almost fully attenuated signal. However if the logic I applied above was sound I would have burnt out the scope/generater but I didn't. Someone please explain this to me and put me out of my misery :)