ABSTRACT When designing with switching regulators, application requirements determine how much input an output capacitance is needed. There are a number of key concerns which effect your selection. The electrical performance requirements of your design play a big part in determining the amount of capacitance required. The transient requirements of your system are very important. The load transient amplitude, voltage deviation requirements, and capacitor impedance each affects capacitor selection. Other important issues to consider are minimizing PCB area and capacitor cost. When selecting input and output capacitance each design has specific requirements which much be addressed. System requirements set hard limits for a design. Depending on what you are trying to accomplish, the amount and type of capacitance can vary.