Modified switched power convertor with zero ripple

A modified power conversion scheme suitable for switched mode converters which addresses the problem of output ripple without incurring an appreciable loss of efficiency is presented. An analog controlled current source is used to inject a current into the load which is equal and opposite to the ripple current due to the switching circuit. The control system ensures that most of the load current is supplied by the switch, and that the current through the controlled current source is limited to small values. In this way high efficiency is maintained. A modified DC-to-DC buck convertor based on this principle has been designed, analyzed, and implemented yielding good agreement with the theory. >