A Novel Multiplexed Power Architecture for Improving Cross Regulation and Efficiency

摘要

With its simplicity and the lowest component count incorporating both energy storage and isolation, the flyback converter is an ideal candidate for power levels up to several hundred watts. One inherent drawback of the topology, however, is its poor cross regulation when used in multiple-output applications [1]. Much effort, therefore, has gone into techniques for improving cross regulation [2]. A novel multiplexed approach to the power architecture, where energy packets are steered by a controller to where they are needed, eliminates this drawback and achieves cross regulation within a fraction of 1% while significantly improving system efficiency when compared to conventional post regulation techniques. The new architecture supports multiple outputs driving both constant current and constant voltage loads, enabling the design of a single switch-mode power conversion stage that powers logic circuitry, USB ports, audio channels, and LED strings simultaneously. Examples of working designs along with respective operating characteristics are presented.