EMI requirements, both radiated and conductive, apply to an overall electronic system. Power modules are one of many components within a system. Since the EMI requirements apply to the overall system, significant effort must be expended on system design to limit noise. Most electronic equipment has only one interface with the power source, which is through the power supply. If adequate EMI filters are inserted between the power supply and the power source, conducted emissions from the power module can be sufficiently suppressed to meet the FCC or CISPR limits without the power module meeting the EMC standard as a standalone component. However, it should be noted that power supplies in stand-alone applications, typically in the form of external power adapters, are required to operate below the conducted EMI limits.