I don't need basics, I know the causes how xenon flash "works" ; I need to know how do they minimise this kind of circuit in microprocessor? My question: The Flash tubes require kVs of potential difference to work. I am aware that big capacitors are required to make them work. This is okay upto digital cameras where they can put big capacitors. But cell phones? I read somewhere that microprocessors can't have big capacitors. So how come they work?