DC/DC step-up converter is applicable on battery-powered equipment. DC/DC step-up converter can be used to generate supply voltages for internal circuits that require higher voltages than the available battery voltage. There’s two kind of converters, inductive and capacitive. Inductive step-up converters have a high efficiency over the entire input voltage range. Capacitive converters-i.e., charge pumps give us a high efficiency over selected input voltage ranges.
To decrease the design time to minimum, using charge pumps is good choice because charge pumps are easier to implement. On capacitive converters, we better use ceramic capacitors to get a low output ripple. The low output ripple can be reduced again with adding L-C filter to the output. With connecting FB to the filter output, we can prevent the spikes enter the error amplifier. The regulation of the output voltages is influenced by the series resistance of the inductor. To avoid loop stability issues, a filter corner frequency of 2.3 MHz was chosen above the 300-KHz switching frequency. [Source: Texas Instruments Application Note]