This question has probably been answered before, but I am having a hard time finding explanations about the capacitors purpose. I have been looking at schematics of led matrix circuits and you can often see the anode row is controlled by a mosfet. The mosfet usually has a 100 uF capacitor connected between the source and gnd. Why is that? is it just to smooth the power supply current drop or is there another purpose. How important is the capacitance value, what would happen, if there was no capacitor.
If you know where I could look this up, just point me in the right direction. Thanks.