This application note presents practical design considerations for battery chargers employing Green Mode FPS (Fairchild Power Switch). It includes designing the transformer and output filter, selecting the components and implementing constant current / constant voltage control. The step-by-step design procedure described in this paper will help engineers design battery chargers more easily. In order to make the design process more efficient, a software design tool, FPS design assistant that contains all the equations described in this paper is also provided. The design procedure is verified through an experimental prototype converter.
This document presents practical design considerations for battery chargers employing Green Mode Fairchild Power Switch (FPS). It covers the design of transformers and output filters, component selection, and the implementation of constant current and constant voltage control. A step-by-step design procedure is described to help engineers design battery chargers more efficiently.
The typical power conversion efficiency is about 0.65 to 0.7.
It is typical to select the DC link capacitor as 2-3uF per watt of input power.
It is typical to set K RF = 0.5- 0.7 for the universal input range.